CALOR 2016

15 May 2016, 08:00 → 20 May 2016, 22:00 Asia/Seoul

EXCO in Daegu, Republic of Korea

​​CALOR 2016 - Daegu, Korea

• Title: XVII^th International Conference on Calorimetry in Particle Physics (CALOR 2016) 
• Date: May 15-20, 2016
• Organizer: Kyungpook National University 
• Venue: EXCO, Daegu

Contact: CALOR 2016 Secretariat ​

Phone: +82-53-746-9966/ Fax: +82-53-746-9007​ Email: calor2016@gmail.com

Sunday, 15 May

Registration

Monday, 16 May

Registration

Opening Session and Invited Talks

Convener: Seh Wook Lee (Kyungpook National University (KR))

1 Welcome address

Speaker: Dongchul Son (Kyungpook National University (KR))

2 Diphoton searches in CMS

Speaker: Paolo Meridiani (Universita e INFN, Roma I (IT))

20160516_DiphotonsAtCMS_final.pdf

3 Searches for BSM physics at ATLAS

Speaker: Luis March Ruiz (Universite de Geneve (CH))

ATLAS_BSM_2016_May_16_LMarch.pdf

10:20 Break

Opening Session and Invited Talks

Convener: Seh Wook Lee (Kyungpook National University (KR))

4 Rare event searches with ultra-low background scintillating calorimeter

Scintillating calorimeter is one of the best detector for interesting rare events searches in nuclear and astroparticle physics such as WIMP-like dark matter as well as neutrinoless double beta decay. In this talk, I will summarize activety on developing low background scintillating calorimeter and its physics achievement in Korea.

Speaker: Hyun Su Lee (CUP, Institute for Basic Science)

Rare_event_search_CALOR2016.pdf

5 Seventy Years of Calorimetry

Speaker: Richard wigmans (Texas Tech)

S1-5.pdf

12:10 LUNCH

Large Hadron Collider

Convener: Francesca Nessi-Tedaldi (Eidgenoessische Tech. Hochschule Zuerich (CH))

6 ATLAS Tile calorimeter calibration and monitoring systems

The ATLAS Tile Calorimeter (TileCal) is the central section of the hadronic calorimeter of the ATLAS experiment and provides important information for reconstruction of hadrons, jets, hadronic decays of tau leptons and missing transverse energy. This sampling calorimeter uses steel plates as absorber and scintillating tiles as active medium. The light produced by the passage of charged particles is transmitted by wavelength shifting fibres to photomultiplier tubes (PMTs), located on the outside of the calorimeter. The readout is segmented into about 5000 cells (longitudinally and transversally), each of them being read out by two PMTs in parallel. To calibrate and monitor the stability and performance of each part of the readout chain during the data taking, a set of calibration systems is used. The TileCal calibration system comprises Cesium radioactive sources, laser and charge injection elements and it allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitization. Based on LHC Run 1 experience, several calibration systems were improved for Run 2. The lessons learned, the modifications, and the current LHC Run 2 performance are discussed.

Speaker: Arthur Chomont (Univ. Blaise Pascal Clermont-Fe. II (FR))

CALOR2016_CalibTileCal.pdf

7 ATLAS Tile Calorimeter time calibration, monitoring and performance

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the central region of the ATLAS experiment at the LHC. This sampling device is made of plastic scintillating tiles alternated with iron plates and its response is calibrated to electromagnetic scale by means of several dedicated calibration systems. The accurate time calibration is important for the energy reconstruction, non-collision background removal as well as for specific physics analyses. The initial time calibration with so-called splash events and subsequent fine-tuning with collision data are presented. The monitoring of the time calibration with laser system and physics collision data is discussed as well as the corrections for sudden changes performed still before the recorded data are processed for physics analyses. Finally, the time resolution as measured with jets and isolated muons particles is presented.

Speaker: Tomas Davidek (Charles University (CZ))

tilecal_time.pdf

8 The CMS Calorimeter Trigger for LHC Run II

The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. During Run II, the LHC has increased its centre-of-mass energy up to 13 TeV and will progressively reach an instantaneous luminosity of 2e34cm-2s-1. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition (DAQ) system has been upgraded. A novel concept for the L1 calorimeter trigger is introduced: the Time Multiplexed Trigger (TMT). In this design, which is similar to the CMS DAQ or High Level Trigger (HLT) architecture, nine main processors each receive all of the calorimeter data from an entire event via 18 preprocessors. The advantage of the TMT architecture is that a global view and full granularity of the calorimeters can be exploited by sophisticated algorithms. The goal is to maintain the current thresholds for calorimeter objects and improve the performance for their selection. The introduction of new triggers based on the combination of calorimeter objects is also foreseen. The performance of these algorithms will be presented, both in terms of efficiency and rate reduction using the proton collision data collected in 2016. The challenging aspect of pile-up mitigation will be addressed. The impact of the improved selection criteria on benchmark physics channels such as Higgs and Supersymmetry will be presented as well in this talk.

Speaker: Aaron Bundock (Imperial College Sci., Tech. & Med. (GB))

ABundock_CMSCaloTrigUp_CALOR_2016_3.pdf

9 Overview of energy reconstruction and electron and photon performances with the CMS ECAL in Run II

The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid (CMS) Experiment is crucial for achieving high resolution measurements of electrons and photons. Maintaining and possibly improving the excellent performance achieved in Run I is vital for measurements of the Standard Model Higgs boson and searches for new higher mass resonances in final states with electrons and photons. The ECAL has operated since Spring 2015 with proton-proton collisions at 13 TeV center-of-mass energy and at a reduced bunch spacing of 25 ns, and it is ready for the 2016 data-taking. The instantaneous luminosity delivered by the LHC during Run II is expected to exceed the levels previously attained. The average number of concurrent proton-proton collisions per bunch-crossing (pileup) is expected to reach up to 40 interactions. In this talk we present new crystal energy reconstruction algorithms and clustering techniques that have been developed to maintain the excellent performance of the CMS ECAL throughout Run II. We will show first performance results from 2015 data, achieved through energy calibrations using electrons from W and Z boson decays, photons from pi0/eta decays, and the azimuthally symmetric energy distribution of minimum bias events. Lastly, we present an outlook on the expected Run II performance in the next years.

Speaker: Rafael Teixeira De Lima (Northeastern University (US))

ECALEnergyOverview_CALOR.pdf

15:20 Break

Large Hadron Collider

Convener: Nural Akchurin (Texas Tech University (US))

10 Study of TileCal scintillators irradiation using the Minimum Bias integrators

The Tile Calorimeter (TileCal) is the central hadronic calorimeter of the ATLAS experiment at the LHC. It provides precise measurements of hadrons, jets, taus and missing transverse energy. The monitoring and calibration of the calorimeter response at each stage of the signal development is allowed by a movable Cs^{137} radioactive source, a laser calibration system and a charge injection system. Moreover, during the LHC data taking, an integrator based readout provides the signals coming from inelastic proton-proton collisions at low momentum transfer (minimum bias currents) and allows to monitor the instantaneous ATLAS luminosity as well as the response of calorimeter cells. Minimum bias currents have been used to detect and quantify the effect of TileCal scintillators irradiation using the data taken in 2012 and 2015, and that corresponds to about 21 fb^{-1} and 4 fb^{-1} of integrated luminosity. FInally, the response variation for an irradiated cells has been studied combining the information from three calibration systems (cesium, laser and minimum bias). The result of the irradiation on the Tile calorimeter response will be reported.

Speaker: Cora Fischer (Universitat Autònoma de Barcelona (ES))

mbias_16052016.pdf

11 Performance of the ATLAS Liquid Argon Calorimeters in LHC Run-1 and Run-2

The ATLAS detector was designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV and instantaneous luminosities up to $10^{34}$ cm$^{-2}$ s${^-1}$. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region $|\eta|<3.2$, and for hadronic calorimetry in the region from $|\eta|=1.5$ to $|\eta|=4.9$.

The calibration and performance of the LAr calorimetry system was
established during beam tests, cosmic ray muon measurements and in
particular the first three years of pp collision data-taking. During
this period, referred to as Run-1, approximately 27~fb$^{-1}$ of data
have been collected at the center-of-mass energies of 7 and
8~TeV. Following a period of detector consolidation during a long shutdown,
Run-2 started in 2015 with approximately 3.9~fb$^{-1}$ of data
at a center-of-mass energy of 13~TeV recorded in this year. Results
on the LAr calorimeter operation, monitoring and data quality, as well as
their performance will be presented, including the
calibration and stability of the electromagnetic scale, response
uniformity and time resolution. These results demonstrate that the
LAr calorimeters perform excellently within their design
requirements. The calorimetry system thus played a crucial role in the
Run-1 physics programme, and, in particular, in the discovery of a Higgs boson.

Speaker: Jose Feliciano Benitez (University of Iowa (US))

LArPerfomance_CALOR2016.pdf

12 The role of the CMS electron and photon trigger in the study of the Higgs boson and other resonances

The Compact Muon Solenoid (CMS) experiment implements a sophisticated two-level triggering system composed of the Level-1, instrumented by custom-design hardware boards, and a software High-Level-Trigger. A new Level-1 trigger architecture with improved performance is now being used to maintain the thresholds used in LHC Run I for the more challenging conditions experienced during Run II. We present the performance of the upgraded CMS electron and photon trigger in the context of Higgs boson decays into final states with photons and electrons. The calorimeter trigger system plays a central role in achieving the ambitious physics program of Run II. The upgraded trigger uses the full granularity of the calorimeters to optimally reconstruct and calibrate the electromagnetic trigger objects. It also implements combinations of calorimeter objects to provide new Level-1 quantities such as invariant mass. Optimized software selection techniques have been developed and advanced algorithms to mitigate the impact of event pileup have been implemented. The performance of these new algorithms will be presented, based on proton-proton collision data collected in 2016. The selection techniques used to trigger efficiently on these benchmark analyses will be presented, along with the strategies employed to guarantee efficient triggering for new resonances and other new physics signals involving electron/photon final states.

Speaker: Mr Thomas Strebler (CMS collaboration - LLR - Ecole Polytechnique (FR))

16.05.16 CMS EG trigger - CALOR2016 - v2.pdf

13 Performance of the CASTOR calorimeter at CMS during Run II of LHC

CASTOR is an electromagnetic and hadronic tungsten-quartz sampling Cerenkov calorimeter located at CMS at the LHC, with pseudorapidity (denoted η) borders at -5.2 and -6.6. To measure in this η acceptance, the (2 tonnes weighing) detector is installed within a distance of 1 cm from the LHC beampipe and at 14.4 m from the interaction point. CASTOR can measure energy deposits, jets and is very well suited to identify forward rapidity gaps. It is an excellent tool for studying forward physics, small-x hadron structure, diffraction and forward low-pt QCD. CASTOR has successfully collected data during LHC Run I and Run II. The purpose of this talk is to give an overview of various aspects of the performance of CASTOR in LHC Run II and the relations between these aspects. We’ll state the key numbers obtained with the design, lessons learned and we point out improvements in the performance w.r.t. Run I. When the magnetic field of CMS is turned on, CASTOR gets displaced from its initial location which makes the installation an even more delicate task. This displacement has also consequences for the alignment of CASTOR which we discuss. For CASTOR the calibration is done in a two step procedure. First the 16 sectors and 24 modules are intercalibrated using muons from dedicatedly selected beam-halo events. To distinguish the small muon signal from noise a good estimate of the noise and baseline per channel of CASTOR is indispensable. We show the pedestal energy spectrum of the PMT's contains contributions from the electronic noise, thermal photoelectrons and ion feedback. After the intercalibration, a provisional absolute scale is obtained by equating the energy of p+p collisions measured with CASTOR with MC based extrapolations of energy measurements with another CMS subsystem. We conclude the calibration by showing some results on the longitudinal and azimuthal profiles of energy in CASTOR in data and MC and the tower noise cutoff obtained from measurements at Run II. We finish by discussing the CASTOR jet trigger efficiency and the collected data samples.

Speaker: Mr Merijn van de Klundert. CMS collaboration (Antwerp University)

CASTOR_MvandeKlundert_Final.pdf

Welcome Reception

Tuesday, 17 May

Experience with current calorimetric systems

Convener: Byung Gu Cheon

14 The NA62 Hadron Calorimeter

NA62 is a fixed target experiment located in the north area of the Prevessin CERN site.\\ The ambitious aim of the experiment is to measure the branching ratio (BR) of the very rare decay $K^{+} \rightarrow \pi^{+} \nu \bar{\nu}$ within 10$\%$ precision using the decay in flight technique.\\ The branching ratio of such a rare decay is very well calculated in the standard model as $(9.11 \pm 0.72) \times 10^{-11}$ and the measurement of this channel represents one of the most promising field for the search of new physics beyond the standard model.\\ The presence of just one detectable track in the final state represents one of the most challenging component on the experimental point of view. The full kinematic reconstruction of the decay allows a strong background suppression. Still the detector resolution, combined with the tiny branching ratio of the signal, makes the $K^{+} \rightarrow \mu^{+} \nu$ decay (whose BR is 0.64) a critical source of background.\\ The NA62 detector was therefore designed to perform an excellent $\pi$/$\mu$ separation using a very efficient particle identification (PID) system. A major role in the PID is played by the calorimeters that provides a muon rejection factor of the order of $10^{5}$ through the measurement of energy and shape of the hadronic showers.\\ The calorimetric system consist of the electromagnetic calorimeter (LKr) filled with liquid krypton and the hadron calorimeter (HAC).\\ This presentation, after illustrating the HAC structure, will report on the calibration procedure of the detector response and the preliminary performance results of the hadronic energy reconstruction.

Speaker: Riccardo Aliberti (Johannes-Gutenberg-Universitaet Mainz (DE))

Calor.pdf

15 Geometric alignment of the SND detector

We present the design, implementation and validation of the software procedure used to perform geometric calibration of the electromagnetic calorimeter with respect to the tracking system of the Spherical Neutral Detector (BINP, Novosibirsk). This procedure is based on the mathematical model describing the relative calorimeter position by means of a set of parameters. The parameter values are determined by minimizing a $ \chi^2 $ function using the difference between directions reconstructed in these two subdetectors for $ e^+e^-->e^+e^- $ data events.

Speaker: Natalya Melnikova (Budker Institute of Nuclear Physics (RU))

GeoCalib_ofTheSND_CALOR2016.pdf

16 Calorimetry of the CMD-3 detector

The CMD-3 detector has been collecting data since 2010 at the e$^+$e$^−$ collider VEPP-2000 at the Budker Institute of Nuclear Physics. The VEPP-2000 uses the novel round beam technique and provides a high luminosity in wide range from 0.3 to 2 GeV in c.m. A physics goal of the CMD-3 experiment is the study of the e$^+$e$^−$ annihilation into hadrons. The CMD-3 is a general-purpose detector which with high efficiency for both charge and neutral particles. The electromagnetic calorimeter is almost 4$\pi$ hermetic. It consists of the barrel calorimeter, based on Liquid Xenon and CsI crystals, and endcap calorimeter, based on BGO crystals. The main parameters of the calorimeters and achieved resolutions is presented.

Speaker: Mr Ravel Akhmetshin (Budker INP)

S3-3.pdf

17 Status of the Top and Bottom Counting Detectors for the ISS-CREAM Experiment

It is important to measure the cosmic ray spectra to study the origin, acceleration and propagation mechanisms of high-energy cosmic rays. A payload of the Cosmic Ray Energetics And Mass (CREAM) experiment is scheduled to launch in 2017 to the International Space Station (ISS) for measuring cosmic ray elemental spectra at energies beyond the reach of balloon instruments. Top Counting Detector (TCD) and Bottom Counting Detector (BCD) as a two-dimensional detector are to separate electrons from nuclei for electron/gamma-ray physics. The T/BCD each consists of a plastic scintillator read out by 20 by 20 photodiodes and is placed before and after the Calorimeter (CAL), respectively. Energy and hit information of the T/BCD can distinguish shower profiles of electrons and nuclei, which show narrower and shorter showers from electrons at a given energy. The T/BCD performance has been studied with the instrument’s Silicon Charge Detector (SCD) and CAL in various energy ranges by using a GEANT3 + FLUKA 3.21 simulation package. By comparing the number of hits and distributions between electrons and protons, we study optimal parameters for the e/p separation. In this presentation, we will show the construction and performance of the T/BCD, and report a status of the simulation study for cosmic ray electron physics.

Speaker: Jeongmin Park (Kyungpook National University (KR), on behalf of the ISS-CREAM Collaboration)

20160517_CALOR2016_JMP_script_rev2.pdf

10:20 Break

Calorimetric systems at non-accelerator

Convener: Tao Hu (IHEP,China)

18 Background Simulation of a search for neutrinoless double beta decay of Mo-100

Background simulations have been performed for an experimental search for neutrinoless double beta decay of ¹⁰⁰Mo in calcium molybdate (CaMoO4) crystals, the Advanced Mo-based Rare Process Experiment (AMoRE). Using GEANT4, effects of radioactive background sources such as ²³⁸U and ²³²Th in the first phase of AMoRE experiment configuration were simulated for the interior of crystals and surrounding materials. Expected background rates including the effect of random coincidence rate of background and double beta decay of ¹⁰⁰Mo have been estimated.

Speaker: Young Soo Yoon (Institute for Basic Science)

20160517_AMoRE_BackgroundSimulation.pdf

19 CaloCube: a innovative homogeneous calorimeter for the next-generation space experiments

The direct measurement of cosmic-ray spectrum, up to the knee region, is one of the instrumental challenge for next-generation space experiments. The main issue for these measurements is a steeply falling spectrum with increasing energy, so the physics performance of the space calorimeters are primarily determined by their geometrical acceptance and energy resolution. CaloCube is a three-years R&D project, approved and financed by INFN in 2014, aiming to optimize the design of a space-borne calorimeter. The peculiarity of the design of CaloCube is its capability of detecting particles coming from any direction, and not only those on its upper surface. To ensure that the quality of the measurement does not depend on the arrival direction of the particles, the calorimeter will be designed as homogeneous and isotropic as possible. In addition, to achieve a high discrimination power for hadrons and nuclei with respect to electrons, the sensitive elements of the calorimeter need to have a fine 3-D sampling capability. In order to optimize the detector performances with respect to the total mass of the apparatus, which is the most important constraint for a space launch, a comparative study of different scintillating materials have been performed using detailed Monte Carlo simulation based on the FLUKA package. Different geometries, besides the cubic one, and the possibility to implement dual-readout techniques have been also investigated. In parallel to simulation studies, a prototype consisting in 14 layers of 3 × 3 CsI(Tl) crystals per layer has been assembled and tested with particle beams. An overview of the obtained results during the first two year of the project will be presented and the future of the detector will be discussed too.

Speaker: Lorenzo Pacini (Universita e INFN, Firenze (IT))

S4-2.pdf

20 A metallic magnetic calorimeter with scintillation crystal for rare event search experiment

The metallic magnetic calorimeter (MMC) operates at tens of millikelvin temperatures, and measures temperature increases caused by particle interactions in detectors. Calorimetric detection of heat and light signals of scintillation crystals using MMCs is a promising detection technique for rare event search experiments because of its high energy resolution, low energy threshold, and particle discrimination performances. We have developed detectors consisting of CaMoO$_{4}$ scintillation crystals and MMCs for the AMoRE (Advanced Mo-based Rare process Experiment) experiment which is searching for neutrinoless double beta decay ($0\nu\beta\beta$) of $^{100}$Mo. A prototype detector has shown a FWHM energy resolution of 9 keV at 2.6 MeV (close to the 0νββ Q-value of $^{100}$Mo) and a 20 $\sigma$ separation power for alpha-induced background events. These performances enable a negligible-background experiment up to tens of kg scale detectors. We present measurement concept and performances of the prototype detector tested at an above-ground laboratory. Also, current status of the AMoRE-pilot experiment with 1.5 kg enriched CaMoO$_{4}$ crystal detectors at the Yang-Yang underground laboratory will be presented.

Speaker: Dr Geon-Bo Kim (Institute for Basic Science)

20160517_CALOR2016_gbkim.pdf

11:50 LUNCH

Poster Session

21 Growth and Characterization of Ce-doped Cs2LiGdBr6 Crystals for Future Crystal Calorimeters

Speaker: Jonghun Jang

22 Growth and characterization of Na2Mo2O7 scintillating crystals

Speaker: Indra Raj Pandey (Kyungpook National Univ.)

23 Impact of Non-Uniformity in Light Collection on the Energy Resolution of the PANDA Electromagnetic Calorimeter at Photon Energies Below 1 GeV

Speaker: Dr Stefan Diehl (Justus-Liebig-Universitaet Giessen (DE))

24 Low light image detection using multi-channel silicon photomultiplier

Speaker: JinA Jeon

25 Optical and luminescence properties of rare-earth (Ce3+, Nd3+, Sm3+ and Er3+)-doped gadolinium calcium silica borate glass scintillators

Speaker: C. R. Kesavulu

26 Simultaneous heat and light detection for 1-cm3 scintillating crystals

Speaker: Hyelim Kim (Kyungpook National University)

27 Study of radiation hardness of un-doped CsI crystals and Silicon Photomultipliers to be used in the Mu2e calorimeter

Speaker: Dr Matteo Martini (LNF-INFN)

28 The fabrication and test of 64 channels of SiPMs

Speaker: Dr Hye Young Lee (SKKU)

Calorimeters for future accelerator experiments

Convener: Richard wigmans (Texas Tech)

29 Status and New Results for the sPHENIX Calorimeter Systems

The PHENIX Experiment at RHIC is planning a major upgrade that involves building an entirely new spectrometer based around the former BaBar solenoid magnet that will enable a comprehensive study of jets and heavy quarkonia in relativistic heavy ion collisions. It will include two new calorimeter systems, one electromagnetic and one hadronic, that will cover an acceptance of ±1.1 units in pseudorapidity and 2pi in phi, resulting in a factor of 6 increase in acceptance over the present PHENIX detector. The hadronic calorimeter, which will be the first hadronic calorimeter ever built at RHIC, will be a steel plate and scintillating tile design that is read out with wavelength shifting fibers and silicon photomultipliers. It will be divided into two sections: an Inner HCAL that will be situated inside the magnet and an Outer HCAL that will be located outside the magnet. The electromagnetic calorimeter will be a SPACAL design consisting of a tungsten powder epoxy matrix absorber with embedded scintillating fibers which are also read out with silicon photomultipliers. The current design of the sPHENIX detector, including the EMCAL and inner and outer HCALs, will be described in this talk. Prototypes of all three calorimeter detectors have been built and will be tested in the test beam at Fermilab in April of 2016 to study the energy resolution, linearity and e/pi ratio of the calorimeter system. The first preliminary results from these tests, along with a detailed comparison to Monte Carlo simulations, will also be presented. In addition, plans to upgrade the sPHENIX detector for use as a Day 1 detector at a future Electron Ion Collider at BNL (eRHIC) will also be discussed.

Speaker: Craig Woody (Brookhaven National Lab)

CALOR_2016_sPHENIX.pdf

30 R&D for high resolution calorimetry at the future Electron-Ion Collider

The prospective future Electron-Ion Collider (EIC) would offer a unique opportunity to understand the role of gluons in strongly interacting nuclear matter. An ambitious generic detector R&D program started in 2011 in order to address the scientific requirements for measurements at such a new facility. In particular, a dedicated consortium was created with the goal of developing new technologies for calorimeter applications at EIC. This R&D is performed by various groups and involves both the central barrel calorimeter, as well as forward calorimetry in both the electron and hadron going directions. In this talk we will focus on the forward calorimetry options, which include the development of tungsten scintillating fiber technology SPACAL, as well as crystal calorimetry, in particular using lead tungstate. We will report on the status of the different projects and plans for the future.

Speaker: Carlos MUNOZ CAMACHO (CNRS)

calor.pdf

calor.pptx

31 A Crystal Shashlik Electromagnetic Calorimeter for Future HEP Experiments

In high energy and nuclear physics experiments, total absorption electromagnetic calorimeters made of inorganic crystals are known for decades for their superb energy resolution and detection efficiency. Significant degradation of crystal performance, however, was observed in a severe radiation environment, such as the LHC. A very compact crystal based shashlik calorimeter was designed for future HEP experiment at an extreme harsh radiation environment, such as the proposed HL-LHC, where thin crystal plates are used as the sensitive medium to reduce the light path length and thus the radiation damage effect. The design of such calorimeter uses tungsten as absorber, radiation hard inorganic crystals, such as LYSO, as active medium, and radiation hard wavelength shifter, such as quartz capillaries, to transport scintillating light to photodetectors. The initial calorimeter design and the performance of prototype modules will be reported. Possible optimization will be discussed.

Speaker: Renyuan Zhu (California Institute of Technology (US))

ryz_160517_calor16_Shashlik.pdf

32 Shower maximum detectors based on pixelated micro-channel plates

Speaker: Adolf Bornheim (California Institute of Technology (US))

Calor2016_MCP.pdf

33 The Status of Calorimeter on CEPC

After the discovery of the Higgs particle, Chinese high energy physics community has proposed circular electron positron collider (CEPC) as a Higgs factory and the pre-CDR has been released in May, 2015. The pre-CDR design of the CEPC detector will be presented and the status of Calorimeter will be focused.

Speaker: Tao Hu (IHEP,China)

CEPC-CALO-Calor2016.pdf

34 Design, status and test of the Mu2e crystal calorimeter

The Mu2e experiment at Fermilab searches for the charged-lepton flavor violating
neutrino-less conversion of a negative muon into an electron in the field of
a aluminum nucleus. The dynamics of such a process is well
modelled by a two-body decay, resulting in a mono-energetic electron with
an energy slightly below the muon rest mass (104.967 MeV).
If no events are observed in three years of running, Mu2e will set a limit on
the ratio between the conversion and the capture rates, \convrate, of $\leq 6\ \times\ 10^{-17} (@ 90 \%$ C.L.). This will improve the current
limit by four orders of magnitude.

A very intense pulsed muon beam ($\sim 10^{10} \mu/$ sec) is stopped on
a target inside a long evacuated solenoid where the detector is located.
The Mu2e detector is composed of a tracker, an electromagnetic
calorimeter and a veto for cosmic rays externally surrounding the
detector solenoid. The calorimeter plays an important
role in providing excellent particle identification capabilities and an
online trigger filter while aiding the track reconstruction capabilities.
It should keep functionality in an environment where the neutron, proton and photon
backgrounds from muon capture processes and beam flash
deliver a dose of $\sim$ 120 Gy/year in the hottest area.
It will also need to work in 1 T axial magnetic
field and a $10^{-4}$ torr vacuum. The calorimeter requirements are
to provide a large acceptance for 100 MeV electrons and reach at this energies:
(1) a time resolution better than 0.5 ns, (2) an energy resolution {\it O($5\%$)};
and (3) a position resolution of {\it O(1)} cm.

The baseline calorimeter configuration consists of two disks, each one
made of $\sim$ 700 undoped CsI crystals read out by two large area
UV extended Silicon Photomultipliers (SIPM). These crystals emit at 310 nm
with a large light yield (30 pe/MeV) when coupled in air to the SIPMs and
provide a fast response and accurate timing having a time emission
of $\tau \sim$ 20 ns. These crystals match the requirements for stability
of response, high resolution and radiation hardness. SIPM signals are amplified,
shaped and then read out through 200 msps waveform digitizers
optically connected to the DAQ system. We present the calorimeter design,
the experimental tests and the simulation carried out to prove the
validity of the chosen configuration. In particular, we will summarise the
results of the test beam with electron beams in the energy range between
80 and 140 MeV and the irradiation program carried out both with crystals
and SiPM.

Speaker: Dr Matteo Martini (LNF-INFN)

S5-6.pdf

15:30 Break

Poster Session

35 Growth and Characterization of Ce-doped Cs2LiGdBr6 Crystals for Future Crystal Calorimeters

Speaker: Jonghun Jang

36 Growth and characterization of Na2Mo2O7 scintillating crystals

Speaker: Indra Raj Pandey (Kyungpook National Univ.)

37 Impact of Non-Uniformity in Light Collection on the Energy Resolution of the PANDA Electromagnetic Calorimeter at Photon Energies Below 1 GeV

Speaker: Stefan Diehl (Justus-Liebig-University Giessen)

38 Low light image detection using multi-channel silicon photomultiplier

Speaker: JinA Jeon

39 Optical and luminescence properties of rare-earth (Ce3+, Nd3+, Sm3+ and Er3+)-doped gadolinium calcium silica borate glass scintillators

Speaker: C. R. Kesavulu

40 Simultaneous heat and light detection for 1-cm3 scintillating crystals

Speaker: Hyelim Kim (Kyungpook National University)

41 Study of radiation hardness of un-doped CsI crystals and Silicon Photomultipliers to be used in the Mu2e calorimeter

Speaker: Dr Matteo Martini (LNF-INFN)

42 The fabrication and test of 64 channels of SiPMs

Speaker: Dr Hye Young Lee (SKKU)

Calorimeters for future accelerator experiments

Convener: Renyuan Zhu (California Institute of Technology (US))

43 Polarimetry concept based on heavy crystal hadron calorimeter

In the upcoming **J**uelich **E**lectric **D**ipole moment **I**nvestigations (**JEDI**) project, the essential point will be to measure a tiny beam polarization change over an extended period of time. The particle scarcity in the polarised deuteron or proton beams and its slow extraction rate puts tough experimental limitations on the polarimetry. For the future EDM measurements, a dedicated high precision polarimeter is required. The new concept is based on the following principles: Achieving maximum identification efficiency for the elastic events off the carbon target, dead time-less data taking and avoiding strong magnetic and electric fields. Also, the experiment will last over several years, so the long-term stability and strong radiation hardness is required. To fulfill these specifications, a fast, dense, high resolution (energy and time), and radioactive hard novel crystal scintillating material is required. LYSO is supposed to be used for particle etection/identification. The LYSO crystal PMT and SiPM readout with FADC based system is under the development. The first proton and deuteron beam test of the prototypes were done and will be presented (talk by F.Mueller). In this presentation, the new polarimetry concept based on heavy crystal hadron calorimeter; first prototype test results and upcoming activities at JEDI@COSY will be overviewed.

Speaker: Dr Irakli Keshelashvili (Forschungszentrum Jülich GmbH)

i.keshelashvili_CALOR2016.pdf

44 LYSO Crystal Testing for an EDM Polarimeter

The (**JEDI**) **J**ülich **E**lectric **D**ipole moment **I**nvestigations collaboration aims to measure tiny polarization changes over a long period of time (see talk by I. Keshelashvili). In the following presentation, the results of beam tests of the new developed LYSO modules for the future polarimeter will be presented. For the tests, four detector modules have been built. The first version of this modules was built using dual channel PMTs. For this beam time at COSY , three different types and two sizes of LYSO crystals from Saint-Gobain and EPIC-Crystals were studied. In a second step, one PMT readout has been replaced by an array of silicon photomultipliers (SiPMs). The SiPM array was read out first, using an OpAmp based pre-amplifier and second, the directly summed signal from the decoupled output of the array. Both versions of the modules have been tested in a deuteron beam with five different energies from 100 MeV up to 270 MeV. The preliminary results of the energy resolutions, the deuteron reconstruction efficiency as well as the energy calibration will be presented.

Speaker: Fabian Müller (Forschungszentrum Jülich GmbH)

Calor16_F_Mueller.pdf

45 Test Beam Studies Of Silicon Timing for Use in Calorimetry

The high luminosity upgrade of the Large Hadron Collider (HL-LHC) at CERN is expected to provide instantaneous luminosities of 5 × 10^34 cm−2 s−1. The high luminosities expected at the HL-LHC will be accompanied by a factor of 5 to 10 more pileup compared with LHC conditions in 2015, causing general confusion for particle identification and event reconstruction. Precision timing allows to extend calorimetric measurements into such a high density environment by subtracting the energy deposits from pileup interactions. Calorimeters employing silicon as the active component have recently become a popular choice for the HL-LHC and future collider experiments which face very high radiation environments. We present studies of basic calorimetric and precision timing measurements using a prototype composed of tungsten absorber and silicon sensor as the active medium. We show that for the bulk of electromagnetic showers induced by electrons in the range of 20 GeV to 30 GeV, we can achieve time resolutions better than 25 ps per single pad sensor.

Speaker: Adolf Bornheim (California Institute of Technology (US))

Calor2016_Si.pdf

46 A fast timing calorimetric layer using micro-channel plates in ionisation mode

At the HL-LHC, more than 140 concurrent pp interactions, will deteriotate the energy resolution and identificatification capabilities of calorimeters. The possibility to distinguish neutral particles coming from different interaction vertices is being pursued as a tool to reduce pile-up contamination in calorimeters, and restore optimal performance. A time of flight resolution of the order of 30ps will be able to reduce pile-up contamination of about one order of magntitude. Micro-channel plates can be used in PMT configuration as fast charged particles detector (resolution of better then 30ps can be achieved), but are not particularly radiation tolerant due to ion feedback on the photocathode. The possibility of using micro-channel plates without a photocatode (i-MCP) has been studied in test beams. Different MCP geometries are compared with the goal to identify the optimal configuration. Efficiency of more then 70% with a time resolution of better then 40ps are achieved for single charged particles, leading to an efficiency close to 100% for EM shower after few radiation lenghts. This open the possibility to use i-MCPs as a timing layer in a sampling calorimeter or to use it in a pre-shower device independent from the calorimeter technology. Preliminary results on the radiation hardness of the i-MCP configuration will be also presented.

Speaker: Vincenzo Ciriolo (Universita & INFN, Milano-Bicocca (IT))

Calor2016_12_def.pdf

47 Belle II Electromagnetic Calorimeter

At present new SuperKEKB collider is under commissioning at KEK (Japan) while the Belle II detector for experiments at this collider is at the final stage of the construction. This new experiment will continue and widen the studies began at the previous experiments with the Belle detector. The luminosity of this collider will exceed the previous one by about 40 times, amounting to $8\times 10^{35}$cm$^{-2}$s$^{-1}$. However, high luminosity is unavoidably accompanied by the high event rate and background. Then the detector should be drastically upgraded. The electromagnetic calorimeter is a very important component of the BELLE II detector. This calorimeter is described in this report. A core part of the calorimeter, 8736 counters based on CsI(Tl) crystals read out by PIN photodiodes, is reused from the Belle detector which operated at the KEKB asymmetric energy collider from 1999 to 2010. Since the project luminosity of the SuperKEKB is 40 times higher than that of the previous collider, much more severe background conditions are expected. Therefore all readout electronics is replaced to a new one that will be able to cope with high event rate.
Signals from preamplifiers attached to the crystals are transmitted to the Shaper Digitizer Boards (SDB). In this board a signal after shaping with a time constant of 0.5us is digitized by 18 bit ADC with 1.8 MHz sampling rate and sent to pipeline buffer in FPGA where waveform fitting is performed to extract energy and timing information. Amplitude and timing data obtained by fit are collected by the Collector Board (CB). The CB sends this information to backend DAQ system. By now all calorimeter DAQ electronics including 576 (432 barrel+144 endcap) SDB and 52 CB are installed to the detector. The barrel part of the calorimeter is tested with cosmic rays.
A second step of the upgrade when the crystals in the end caps are replaced by the fast pure CsI crystals is under study. Since the photon emission of undoped CsI crystal is roughly 10 times smaller than that of doped one, the photosensors with amplification should be used. Current baseline option is vacuum photopenthods, their characteristics and performance study is presented. An option of a read out with the large area APD is also under study.

Speaker: Boris Shwartz (Budker Institute of Nuclear Physics, Novosibirsk)

S6-5.pdf

48 Status of the electromagnetic calorimeter trigger system at the Belle II.

The Belle II experiment at SuperKEKB collider in Japan has been under the construction toward physics run in 2017 with 40 times higher instantaneous luminosity than the KEKB collider. The main physics goal of the Belle II is to search for the New Physics in rare B decays and tau lepton decays. We have developed an Electromagnetic Calorimeter hardware trigger system that generates a trigger signal by two main triggers, total energy and cluster counting. In this talk, we present the overall design scheme and current status of the ECL trigger system.

Speaker: Sung-Hyun Kim

Calor2016.pdf

49 LYSO based precision timing calorimeters

In this report we outline the study of the development of calorimeter detectors using bright scintillating crystals. We discuss how timing information with a precision of a few tens of pico seconds and below can significantly improve the reconstruction of the physics events under challenging high pileup conditions to be faced at the High-Luminosity LHC or a future hadron collider. The particular challenge in measuring the time of arrival of a high energy photon lies in the stochastic component of the distance of initial conversion and the size of the electromagnetic shower. We present studies and measurements from test beams for calorimeter based timing measurements to explore the ultimate timing precision achievable for high energy photons of 10 GeV and above. We focus on techniques to measure the timing with a high precision in association with the energy of the photon. We present test-beam studies and results on the timing performance and characterization of the time resolution of LYSO-based calorimeters. We demonstrate time resolution of 30 ps is achievable for a particular design.

Speaker: Adolf Bornheim (California Institute of Technology (US))

Calor2016_LYSO.pdf

Wednesday, 18 May

High Luminosity LHC

Convener: Ana Maria Henriques Correia (CERN)

50 Upgrade of the ATLAS Liquid Argon Calorimeters for the HL-LHC

The increased particle flux at the high luminosity phase of the LHC (HL-LHC) with instantaneous luminosities of up to $7.5$ times the original design value of $10^{34}$ cm$^{-2}$ s$^{-1}$ will have an impact on many sub-systems of the ATLAS detector. In particular, in the Liquid Argon (LAr) forward calorimeter (FCal), which was designed for operation at LHC luminosities, the associated increase in the ionization load at HL-LHC luminosities poses a number of problems that can degrade its performance, related to beam heating, space charge effects in the liquid Argon gaps and HV drop due to increased current drawn over the HV current-limiting resistors. One solution to these problems, which would require the opening of both endcap cryostats, is the construction and installation of a new FCal, with cooling loops, narrower liquid Argon gaps, and lower value protection resistors. In addition, the proposed new FCal, covering a pseudo-rapidty region of 3.1<$|\eta|$<4.9, will have an increased granularity in its front-most module leading to better pile-up rejection and higher resolution of jet substructure. Effects of pile-up are furthermore planned to be reduced in the whole LAr calorimeter end-cap region, 2.5<$|\eta|$<5.0, by inserting a high-granularity timing detector (HGTD) at the front face of the end-cap cryostat. Multi-layer sensors, interleaved with absorber material at lower $|\eta|$, are foreseen to provide precision timing information for charged and neutral particles with a time resolution of 30 ps in order to assign the particle tracks to different proton-proton collision vertices. Using the information from several hundred thousand sensor elements, the contribution from pile-up jets can be significantly reduced, while preserving a high efficiency for hard-scatter jets. Sensor technologies under investigation are Low Gain Avalanche Detectors (LGAD), pin diodes, and HVCMOS sensors. The talk will review the design of the new high-granularity forward calorimeter and timing detectors for ATLAS, discuss the proposed detector technologies as well as the expected performance at HL-LHC luminosities.

Speaker: Richard Polifka (University of Toronto (CA))

Polifka_CALOR2016.pdf

51 Upgrade of Tile Calorimeter of the ATLAS detector for the High Luminosity LHC

The Tile Calorimeter (TileCal) is the hadronic calorimeter of ATLAS covering the central region of the ATLAS experiment. TileCal is a sampling calorimeter with steel as absorber and scintillators as active medium. The scintillators are read-out by wavelength shifting fibers coupled to photomultiplier tubes (PMT). The analogue signals from the PMTs are amplified, shaped and digitized by sampling the signal every 25 ns. The High Luminosity Large Hadron Collider (HL-LHC) will have a peak luminosity of 5x10^34 cm-2s-1, five times higher than the design luminosity of the LHC. TileCal will undergo a major replacement of its on- and off-detector electronics for the high luminosity programme of the LHC in 2026. The calorimeter signals will be digitized and sent directly to the off-detector electronics, where the signals are reconstructed and shipped to the first level of trigger at a rate of 40 MHz. This will provide a better precision of the calorimeter signals used by the trigger system and will allow the development of more complex trigger algorithms. Three different options are presently being investigated for the front-end electronic upgrade. Extensive test beam studies will determine which option will be selected. Field Programmable Gate Arrays (FPGAs) are extensively used for the logic functions of the off- and on-detector electronics. One hybrid demonstrator prototype module with the new calorimeter module electronics, but still compatible with the present system, is planned to be inserted in ATLAS by the end of 2016.

Speaker: Eduardo Valdes Santurio (Stockholm University (SE))

Upgrade_of_Tile_Calorimeter_of_the_ATLAS_detector_for_the_High_Luminosity_LHC_v6.pdf

52 HGCAL: A High-Granularity Calorimeter for the Endcaps of CMS at HL-LHC

Calorimetry at the High Luminosity LHC (HL-LHC) faces two enormous challenges, particularly in the forward direction: radiation tolerance and unprecedented in-time event pileup. To meet these challenges, the CMS experiment has decided to construct a High Granularity Calorimeter (HGCAL), featuring a previously unrealized transverse and longitudinal segmentation, for both electromagnetic and hadronic compartments. This will facilitate particle-flow-type calorimetry, where the fine structure of showers can be measured and used to enhance particle identification, energy resolution and pileup rejection. The majority of the HGCAL will be based on robust and cost-effective hexagonal silicon sensors with ~1cm^2 or 0.5cm^2 hexagonal cell size, with the final 5 interaction lengths of the hadronic compartment being based on highly segmented plastic scintillator with on-scintillator SiPM readout. We present an overview of the HGCAL project, including the motivation, engineering design, readout/trigger concept and simulated performance.

Speaker: Dr Christophe Ochando (Centre National de la Recherche Scientifique (FR))

ochando_hgcalCMS_18Mayt16_v2.pdf

53 Construction and First Beam-tests of a Prototype Silicon-Tungsten High Granularity Calorimeter for CMS at HL-LHC

The High Granularity Calorimeter (HGCAL) is the technology choice of the CMS collaboration for the endcap calorimetry upgrade planned to cope with the harsh radiation and pileup environment at the High Luminosity-LHC. The HGCAL is realized as a sampling calorimeter, including an electromagnetic compartment comprising 28 layers of silicon pad detectors with pad areas of 0.5 — 1.0 cm^2 interspersed with absorbers made from tungsten and copper to form a highly compact and granular device. A silicon-based single-layer prototype has been constructed and tested in beams at FNAL. The prototype includes many of the features required for this challenging detector, including a complex PCB glued directly to the sensor, using through-hole wire-bonding for signal readout and ~5mm spacing between layers – including the front-end electronics and all services. We present results from first tests of this prototype with beams of electrons and pions of up to 32 GeV/c as well as 120 GeV/c protons, and describe the plans for more extensive prototypes to be tested in beams at FNAL and CERN in 2016.

Speaker: Zoltan Gecse (Fermi National Accelerator Lab. (US))

HGCtestbeamMay18CALOR2016v2.pdf

09:50 Break

High Luminosity LHC

Convener: Adam Para (Fermilab)

54 Precision timing with PbWO crystals and prospects for a precision timing upgrade of the CMS electromagnetic calorimeter at HL-LHC

The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid (CMS) Experiment is made of about 75000 scintillating lead tungstate crystals arranged in a barrel and two endcaps. The single-channel time resolution of ECAL measured at beam tests and for high energy showers from LHC Run I is better than 100 ps. For the high luminosity phase of the LHC (HL-LHC) we expect an average of 140 to 200 concurrent interactions per bunch crossing (pile-up). This poses a major challenge to the event reconstruction. Studies indicate that very precise timing information, at the level of a few 10 ps, could be exploited for pileup mitigation and for the correct assignment of physics objects to their proper vertices. We will discuss some case studies of the usage of precision timing for HL-LHC. The crystal matrix of the CMS ECAL barrel will be used in the HL-LHC upgrade of the CMS detector. We present results on our R&D program to explore the ultimate timing performance of a PbWO-based crystal calorimeter. Simulation studies on the timing properties of PbWO crystals, as well as the impact of the photosensors and the readout electronics on the timing performance, will be presented. Test beam studies on the timing performance of PbWO crystals with various photosensors and readout electronics will be shown.

Speaker: Simone Pigazzini (Universita & INFN, Milano-Bicocca (IT). On behalf of the CMS collaboration)

slides.pdf

55 Concepts and design of the CMS High Granularity Calorimeter Level 1 Trigger

The CMS experiment has chosen a novel high granularity calorimeter for the forward region as part of its planned upgrade for the high luminosity LHC. The calorimeter will have fine segmentation in both the transverse and longitudinal directions and will be the first such calorimeter specifically optimised for particle flow reconstruction to operate at a colliding beam experiment. The calorimeter data will form part of the Level 1 trigger of the CMS experiment and, together with the tracking information, which will also be available at this level, should allow particle flow techniques to be used as part of this trigger. The trigger has tight constraints on latency and rate and will need to be implemented in hardware. The high granularity results in around six million readout channels in total and so presents a significant challenge in terms of data manipulation and processing for the trigger; the trigger data volumes will be an order of magnitude above those currently handled at CMS. In addition, the high luminosity will result in an average of 140 interactions per bunch crossing that give a huge background rate in the forward region and these will need to be efficiently rejected by the trigger algorithms. Furthermore, reconstruction of the particle clusters to be used for particle flow in events with high hit rates is also a complex computational problem for the trigger. The status of the trigger architecture and design, as well as the concepts for the algorithms needed in order to tackle these major issues, will be presented.

Speaker: Jean-Baptiste Sauvan (CERN)

calor2016_hgcal.l1.trigger_sauvan.pdf

56 Electronics Development for the ATLAS Liquid Argon Calorimeter Trigger and Readout for Future LHC Running

The upgrade of the LHC will provide up to 7.5 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon (LAr) Calorimeters. Radiation tolerance criteria and an improved trigger system with higher acceptance rate and longer latency require an upgrade of the LAr readout electronics. In the first upgrade phase in 2019-2020, a trigger-readout with up to 10 times higher granularity will be implemented. This allows an improved reconstruction of electromagnetic and hadronic showers and will reduce the background for electron, photon and energy-flow signals at the first trigger level. The analog and digital signal processing components are currently in their final design stages and a fully functional demonstrator system is operated and tested on the LAr Calorimeters. In a second upgrade stage in 2024-2026, the readout of all 183,000 LAr Calorimeter cells will be performed without trigger selection at 40 MHz sampling rate and 16 bit dynamic range. Calibrated energies of all cells will be available at the second trigger level operating at 1 MHz, in order to further mitigate pile-up effects in energy reconstruction. Radiation tolerant, low-power front-end electronics optimized for high pile-up conditions is currently being developed, including pre-amplifier, ADC and serializer components in 65-180 nm technology. This talk will give an overview of the future LAr readout electronics and present research results from the two upgrade programs.

Speaker: Steffen Starz (CERN)

Electronics Development for the ATLAS Liquid Argon Calorimeter - Trigger and Readout for Future LHC Running

FREE TIME FOR EXCURSIONS (Gyeongju)

Thursday, 19 May

High Luminosity LHC

Convener: Boris Shwartz (Budker Institute of Nuclear Physics, Novosibirsk)

57 Challenges of Particle Flow reconstruction in the CMS High-Granularity Calorimeter at the High-Luminosity LHC

Speaker: Frank Chlebana (Fermi National Accelerator Lab. (US))

CALOR2016-Chlebana.pdf

58 Fast-timing capabilities of silicon sensors for the CMS High-Granularity Calorimeter at the High-Luminosity LHC

Speaker: Nural Akchurin (Texas Tech University (US))

CALOR2016_Akchurin_v1.pdf

59 Performance requirements of the hadronic calorimetry for a 100 TeV proton-proton collider and the potential of an ATLAS-Tile concept readout by si-PMTS

Speaker: Ana Maria Henriques Correia (CERN)

CALOR2016 AnaHenriques 18 may pdf.pdf

10:00 Break

Challenges for calorimeters

Convener: John Michael Hauptman (Iowa State University (US))

60 Energy resolution and timing performance studies of a W-CeF3 sampling calorimeter with a wavelength-shifting fiber readout

The performance of a sampling calorimeter consisting of tungsten and CeF$_3$ crystals read out with wavelength shifting fibers was evaluated in multiple electron beam tests and compared to a GEANT4 simulation. At the Beam Test Facility in Frascati, Italy, electrons with an energy of up to 491 MeV delivered a first proof of principle on the performance of the W-CeF$_3$ prototype. At the SPS-H4 beam line at CERN, electrons with an energy of up to 150 GeV allowed for an in-depth study of the energy resolution and of the response as a function of the impact point. A further beam test, where cerium-doped quartz fibers were used for wavelength-shifting, showed an energy resolution matching the expectations. First tests of the timing performance showed that a resolution better than 100 ps is achievable with SiPMs.

Speaker: Myriam Schoenenberger (Eidgenoessische Tech. Hochschule Zuerich (CH))

WCeF3_CALOR2016.pdf

61 Detection of high energy muons with sub-20 ps timing resolution using L(Y)SO crystals and SiPM readout

Precise timing capability will be a key aspect of particle detectors at future high energy colliders, as the time information can help in the reconstruction of physics events at the high collision rate expected there. Other than being used in detectors for PET, fast scintillating crystals coupled to compact Silicon Photomultipliers (SiPMs) constitute a versatile system that can be exploited to realize an ad-hoc timing device to be hosted in a larger high energy physics detector. In this work we present the timing performance of LYSO:Ce and LSO:Ce codoped 0.4% Ca crystals coupled to SiPMs, as measured with 150 GeV muons at the CERN SPS H2 extraction line. Small crystals, with lengths ranging from 5 mm up to 30 mm and transverse size of 2x2 mm² or 3x3 mm², were exposed to a 150 GeV muon beam. SiPMs from two different companies (Hamamatsu and FBK) were used to detect the light produced in the crystals. The best coincidence time resolution value of (14.5±0.5) ps, corresponding to a single-detector time resolution of about 10 ps, has been measured for 5mm long LSO:Ce,Ca crystals coupled to FBK SiPMs, when time walk corrections are applied. The results obtained in this test improve our understanding of the several factors influencing time resolution in light based devices, e.g. light production and light transport, and confirm the potential of this technology for precise time measurements.

Speaker: Marco Toliman Lucchini (CERN)

TB_Timing_Calor2016.pdf

62 Use of multivariate regression techniques for ultimate energy measurement

The measurement of electromagnetic showers in a transversely segmented calorimeter may be subject to local containment losses related to gaps between the segments which vary according to the position and angle of the incident particle. Furthermore in the case where a significant amount of material is present upstream of the calorimeter within a strong magnetic field, some fraction of the energy of the initial particle may not reach the calorimeter or may not be included in the clustering used to reconstruct the shower. The amount of energy lost to such mechanisms depends on the distribution of upstream material, but also is subject to significant stochastic fluctuations. In a hadronic environment, electromagnetic showers may be further contaminated by additional energy from hadronic activity, primarily from low energy photons produced by neutral meson decays. To the extent that these effects do not entirely factorize, and that information relevant to the shower to shower variations and fluctuations is available in the profile of the shower itself, optimal energy reconstruction may be achieved with multivariate regression techniques. These techniques may also provide a per-shower estimate of the energy resolution, which may vary significantly according to the properties of the shower. We describe a particular implementation of these methods for the CMS Electromagnetic Calorimeter, and evaluate the performance in terms of energy measurement for both data and simulated LHC events. This specific implementation includes extensions of traditional Boosted Decision Tree-based regression algorithms to more explicitly take into account the shape of the energy response distribution.

Speaker: Josh Bendavid (California Institute of Technology (US))

calorRegressionMay19-2016.pdf

63 Beam Test Calibration of the ISS-CREAM Calorimeter

The Cosmic Ray Energetics And Mass (CREAM) instrument was designed to measure high energy ($10^{11} – 10^{15}$ eV) cosmic-ray nuclei from hydrogen to iron in a series of balloon flights. Its follow-up experiment for the International Space Station, so called ISS-CREAM, is configured with four layers of Silicon Charge Detector for charge measurements, and an ionization calorimeter (CAL) for energy measurements. In addition, scintillator-based Top and Bottom Counting Detectors and a Boronated Scintillator Detector distinguish electrons from nuclei. The ISS-CREAM CAL is configured with a densified carbon target followed by a sampling tungsten/scintillator calorimeter like the CAL flown on balloons. However, the layers of the CAL are glued together with an epoxy/fiberglass mixture between layers to meet the mechanical requirements of a rocket launch. We report on the performance of the ISS-CREAM calorimeter in response to hadrons and electrons in beam tests at CERN’s SPS. The results will be compared with previous beam tests for the balloon-borne CAL. The planned in-flight LED and charge calibration tests will also be presented.

Speaker: Young Soo Yoon (Institute for Basic Science)

CALOR2016_ISSCRM_Cal_YS.pdf

11:50 LUNCH

Challenges for calorimeters

Convener: Jim Brau (University of Oregon (US))

64 Proton Induced Radiation Damage up to 8E+15 p/cm2 in Various Crystal Scintillators

Future high energy physics experiments at the energy and intensity frontiers will face challenges of a severe radiation environment from both ionization dose and charged and neutral hadrons. This paper reports an investigation on proton induced radiation damage in various crystal scintillators. Large size BGO, CeF3, LYSO and PWO crystals of 15 to 22 cm long were irradiated by 800 MeV protons at the Weapons Neutron Research facility of Los Alamos Neutron Science Center up to 3 × 10^{15} p/cm^2 with degradation and recovery of their longitudinal transmittance measured in situ. LYSO plates of 14×14×1.5 mm^3 were irradiated by 67 MeV protons at Crocker facility of UC Davis up to 9.5 × 10^{13} p/cm^2, and by 24 GeV protons at the IRRAD facility at CERN up to 8.2 × 10^{15} p/cm^2. Degradations in both transmittance and light output are reported. The results show an excellent radiation hardness of LYSO crystals against charged hadrons.

Speaker: Ren-Yuan Zhu (California Institute of Technology)

Liyuan_160519_Proton_Calor2016.pdf

65 Beam tests of proton-irradiated PbWO4 crystals and evaluation of double side read-out technique for mitigation of radiation damage effects

The harsh radiation environment in which detectors will have to operate during the High Luminosity phase of LHC (HL-LHC) represents a crucial challenge for many calorimeter technologies. In the CMS forward calorimeters, ionizing doses and hadron fluences will reach up to 300 kGy (at a dose rate of 30 Gy/h) and 2x10^{14} cm^{-2}, respectively, at the pseudo-rapidity region of |η|=2.6. To evaluate the evolution of the CMS ECAL performance in such conditions, a set of PbWO_{4} crystals, exposed to 24 GeV protons up to integrated fluences between 2.1x10^{13} cm^{-2} and 1.3x10^{14} cm^{-2}, has been studied in beam tests. A degradation of the energy resolution and a non-linear response to electron showers are observed in damaged crystals. Direct measurements of the light output from the crystals show the amplitude decreasing and pulse becoming faster as the fluence increases. The evolution of the PbWO_{4} crystals calorimetric performance has been well understood and parameterized in terms of increasing light absorption inside the crystal volume. A double side read-out configuration, in which two identical photodetectors are coupled to the opposite ends of each crystal, has also been tested. The separate and simultaneous read out of the light from the two sides of the crystal allows to correct for longitudinal shower fluctuations and to mitigate the degradation of energy resolution in highly damaged crystals. The non-linear response to electromagnetic showers, arising from high non-uniformity of light collection efficiency along the longitudinal axis of irradiated crystals, can also be corrected by means of the double side read-out technique.

Speaker: Marco Toliman Lucchini (CERN)

CALOR2016_Lucchini_ECAL_DRO_talk.pdf

66 Radiation effects on hadronic calorimeters at the LHC

The experiments at the LHC are expected to accumulate up to 300 fb^-1 of data before the major upgrades, known as the “phase II” upgrades, are installed. In this talk, we present studies on the longevity of the active materials used in the barrel and endcap hadronic calorimeters. We present results of in situ measurements of the light output as a function of integrated luminosity and studies of light output as a function of dose using various other sources of irradiation both for the current materials and for potential alternative materials that are less susceptible to radiation damage. We present results on jet resolutions as a function of dose, including schemes to mitigate the impact of the reduced light output, such as increased segmentation of the active material readout.

Speaker: Geng-Yuan Jeng (University of Maryland (US))

CALOR16-Jeng-20160519_final.pdf

67 Volume crystals for extremely high radiation levels

In last two decades a large number of scintillator materials including inorganic crystals have been studied and optimized and their properties are now well understood. Depending on the application, a material is selected to fulfill the most important properties and eventually its further improvement is considered.
In calorimetric detectors at high luminosity colliders in high energy physics, the properties of critical importance are the radiation resistance, speed of scintillation response and up to a lesser extent the light output and density.
As these applications usually require a large volume of scintillation materials its cost becomes also important and is influenced by the price of raw material, the material preparation method and production yield and final manufacturing of the scintillation element.
A new crystal growth method CRIG (CRystal Improved Growth) has been developed to grow large core-free single crystals of yttrium aluminum garnet (YAG).
Using this method [1], the crystals of unmatched quality are produced as for the size, homogeneity, low stress etc.
The growth of 6 inch diameter undoped YAG as well as YAG:Ce has been accomplished in CRYTUR spol. s r.o. This technology can be essential in its application in large scale detectors in high energy physics where single crystals of YAG:Ce is also considered.
The characteristics of CRIG grown method will be presented together with the properties of YAG:Ce standard scintillator. First steps for optimization of YAG:Ce scintillator for high enery physics application will be discussed as well.

• corresponding author e-mail: ochesanu@crytur.cz
  [1] Jindrich Houzvicka, Karel Bartos, patent EP 2675944 A1

Speaker: Mrs Silvia Ochesanu (Crytur spol. s.r.o.)

CRYTUR_Calor2016_final_version.pdf

68 Progress in the Development of the Lead Tungstate Crystal for EM-Calorimetry in High-Energy Physics

Even at present time there is a strong interest and demand for high quality lead tungstate crystals (PbWO4, PWO) for electromagnetic (EM) calorimetry. PWO is implemented into the EM calorimeter of the CMS-ECAL detector at LHC [1] and required for the completion of the PANDA EMC [2] and various ongoing detector projects at Jefferson Lab. The successful mass production of PWO using the Czochralski method was stopped after bankruptcy of the Bogoroditsk Technical Chemical Plant in Russia as major producer so far. The Shanghai Institute of Ceramics, Chinese Academy of Science (China) was considered as an alternative producer using the modified Bridgman method. The company CRYTUR (Turnov, Czech Republic) with good experience in the development and production of different types of inorganic oxide crystals has re-started end of 2014 the development of lead tungstate for the mass production based on the Czochralski method. An impressive progress was achieved since then. The growing technology was optimized to produce full size samples with the quality meeting the PANDA EMC specifications for PWO-II. We will present a detailed progress report on the research program in collaboration with groups at Orsay and JLab. The full size crystals will be characterized with respect to optical performance, light yield, kinetics and radiation hardness in comparison to most recent results from samples produced by SICCAS. [1] E. Auffray et al., “Status of PWO crystal production for the electromagnetic calorimeter of CMS and of its construction,” Nucl. Instr. and Meth. in Phys. Res. A, vol. 537, Issues 1-2, pp. 373-378, Jan. 21, 2005. [2] A. Borisevich et al., “Lead tungstate crystal with increased light yield for the PANDA electromagnetic calorimeter,” Nucl. Instr. and Meth. in Phys. Res. A, vol. 537, Issues 1-2, pp. 101-104, Jan. 21, 2005.

Speaker: Rainer Willi Novotny (Justus-Liebig-University)

S10-5.pdf

S10-5.pptx

69 Gamma-ray Induced Radiation Damage up to 340 Mrad in Various Scintillation Crystals

Because of their superb energy resolution and detection efficiency scintillation crystals are widely used in high energy and nuclear physics experiments. A crucial issue is radiation damage in crystals. We report an investigation on ɣ-ray induced radiation damage in various crystal scintillators of large size, including BaF2, BGO, CeF3, pure CsI, LSO/LYSO/LFS and PWO, with an integrated dose up to 340 Mrad and a dose rate up to 1 Mrad/h. Optical and scintillation properties of these crystal samples were measured before and after irradiations. The results show that pure CsI has good radiation hardness below 100 krad. BaF2, BGO and LYSO have good radiation hardness beyond 1 Mrad. In terms of light output degradation LYSO is clearly the best among all scintillation crystals.

Speaker: Renyuan Zhu (California Institute of Technology (US))

Fan_160519_Gamma_Calor2016.pdf

15:30 Break

Challenges for calorimeters

Convener: Craig Woody (Brookhaven National Lab)

70 Time development of hadron showers and its use in hadron calorimetry

I was unable to find out how to include figures here.. I have emailed the abstract to calor2016

Speaker: Adam Para (Fermilab)

S11-1.pdf

S11-1.pptx

71 Hadron Calorimetry Test Bench

Today particle physics experiments conducted at the energy and intensity frontiers demand more and more sophisticated detectors. The scale of the detectors increases, and that translates into ever increasing costs. This naturally affects calorimetry R&D activities which are conducted by larger groups, often within multi-institutional and multi-national collaborations. And usually it takes years to finalize the design of the new calorimeter while very few alternative design options are considered. “Clustering” of R&D within larger collaborations results in fewer groups doing generic calorimetry studies. Calorimetry community needs tools and methods which allow diversified, yet inexpensive, R&D studies. Such tools and methods would lead to better optimization of the final detector design, meanwhile reducing costs. At the same time, inexpensive calorimetry tools allow smaller groups to organize and conduct small and mid-scale experiments over short periods of time. Sampling calorimetry test benches are among such tools. Using the test bench, one can carry extensive systematic R&D studies with the objective to tune the test bench calorimeter stack to the optimal constant or varying sampling fraction for the energies of interest. Compensation, metrological, and mechanical engineering limits can be optimized with the test bench, as well. Reconfigurable test benches allow wealth of studies before one progresses to building a prototype detector. We designed and fabricated a reconfigurable test bench for hadron calorimetry studies. The test bench includes: 1) a box-case made of sheet steel, the length of the box-case is about 2 m, 2) 380 antimony lead plates with antimony content of ~10%, the dimensions of each plate are 350 mm x 350 mm x 2 mm, 3) 210 polystyrene scintillator tiles, the dimensions of each tile are 350 mm x 350 mm x 4 mm, 4) fourteen polystyrene scintillator tiles, the dimensions of each tile are 350 mm x 350 mm x 5 mm, 5) 232 polystyrene non-scintillator tiles, the dimensions of each tile are 350 mm x 350 mm x 2 mm, 7) five steel plates with thicknesses of 40 mm or less, the lateral dimensions of each plate are 350 mm x 350 mm, 7) six 36-fiber bundles, 8) two 12-fiber bundles, 9) four 4-fiber bundles, 10) two 2-fiber bundles. Clear-wave guides are in the fiber bundles. Thin lead plates allow making absorber layers of various thicknesses, such as 2 mm, 4 mm, 6 mm, …, 12 mm, …, 24 mm, …, 36 mm, …, and so on. Lead-scintillator configurations can be chosen with uniform or variable thicknesses of the absorber layers through the depth of the test bench. The box-case is assembled from steel components. A support is made of 30 mm thick steel sheet welded to one I-beam and twelve C-beams. Two frames made of sheets with milled windows are attached to the support’s front and rear ends. Two side walls are attached to the support C-beams and to the front and rear frames. Each side wall has milled slots that run with a step of 120 mm along the length of the wall. The slots in opposing walls allow fixing the stack of absorbers and scintillators inside the box-case for a certain chosen total thickness of the stack. Kuraray Y-11 wavelength shifting fiber (diameter = 1.2 mm) is glued with optical cement in grooves made in the scintillator tiles. Fibers are glued in the scintillator tiles in such a way that the light is read out from two fiber ends that exit the tile. Upon exiting the tile, the wavelength-shifting fibers are coupled through optical silicone to clear-wave guides that transmit the light to Phillips XP2262/H04 photomultipliers. Each photomultiplier serves a bundle of clear-wave guides that bring the light from several scintillator tiles. Depending on chosen thicknesses of absorber layers, one or several photomultipliers read out the data with help of CAMAC-based data acquisition system. Non-scintillator thin plastic tiles can be used to research mechanical design options for the real hadron calorimeters. Such non-scintillator tiles can be placed between scintillator tiles and absorbers to see how the energy resolution and compensation are affected from such placement. Fourteen 5 mm thick scintillator tiles can be attached to the side walls of the box-case to study lateral shower leaks. Performance of the test bench was preliminarily studied at T9 beam line of CERN Proton Synchrotron with beam momenta ranging from 1 GeV/c to 10 GeV/c. Energy responses of the test bench to hadron, electron and muon beams were measured with absorber thicknesses of 16 mm, 24 mm, and 48 mm.

Speaker: Dr Dmitri Kotchetkov (Ohio University)

Hadron_Calorimetry_Test_Bench.pdf

72 Last development of composite detectors is proposed for HEP application.

Composite radiation detector consist of the scintillation particles distributed in optically transparent media. For the best scintillation light registration the fiber or plate readout technique is used. It is found that general light output in such detector can reach 80-85% comparing to single crystalline detector. For HEP application both radiation hard scintillation powder (like garnets or silicates, for example) and optically transparent media (on the base on polysiloxane gels) were found. Preliminary tests confirmed the optical stability at polymer matrix up to 100 Mrad that significantly over plastic scintillators. Preliminary tests demonstrated the high radiation stability for composites itself too. Optimization of the particle size, their distribution along the optical media and light receiver (fiber) allows to modify detector parameters for different applications. The data/parameters for several combinations on the base on GGAG, YAG, YSO will be announced in this presentation. Composites production technology allows to cover few crucial issues for HEP use. These are the low cost (not necessary to grow crystal) of scintillator, large area detector production (no limits from technology side), flexible and complex shape (due to optical media flexibility), industrial availability of all basic components.

Speaker: Andriy Boyaryntsev (Inst. for Scint. Materials of Nat. Acad. of Science of Ukraine)

CALOR-May 2016(version 4 final (2).pdf

CALOR-May 2016(version 4 final (2).ppt

73 On the saturation of response of inorganic scintillators to slow charged particles

Inorganic scintillators, mostly in a form of scintillating crystals, are widely used in precision calorimetry, mostly electromagnetic. Their use for large scale hadron/jet calorimetry may be limited by practical considerations, like cost, but on a smaller scale they might offer an attractive possibility of precise total absorption calorimetry. The sub-percent energy resolution of electromagnetic calorimetry based on crystals, even in large systems, has been demonstrated in many experiments. Their energy resolution in hadron calorimetry applications may be limited by several effects. A significant fraction of energy of hadronic showers is deposited by slow protons and nuclear fragments, which may produce significantly lower light signals thus inducing the additional contribution to energy resolution. Extensive studies of response of various crystals to low energy protons and ions have been reported and large saturation effects have been observed and parameterized as a function of the energy, atomic number and charge of beam particles. Significant nonlinearity of response have been reported recently for low energy electromagnetic showers as well and a major effort has been devoted to the studies of the physical origins of this ‘non-proportionality’. These studies are limited to the case of electromagnetic calorimetry. We present a simple physical model of the saturation of the crystal response to slowly moving charge and demonstrate that such a model provides an universal description of the observed saturation effects for all hadrons and electromagnetic particles.

Speaker: Adam Para (Fermilab)

S11-4.pdf

S11-4.pptx

74 Study of the New Glass and Glass ceramic Stoichiometric and Gd-loaded BaO*2SiO2 (DSB) Scintillation Material for Future Calorimetry, and Studying of properties of the plastic scintillator EJ-260 under the irradiation with 150 MeV protons and 1.2 MeV gamma-rays

In the last decades crystalline inorganic scintillation material has played a dominant role in calorimetry in medium and high energy physics experiments. Future detector developments will have to focus on cheap, fast, and radiation hard materials, especially for application in collider experiments. In order to increase the radiation hardness with respect to hadronic damage systematic studies of scintillation materials with lower effective nuclear charge have been initiated in particular with the LHC upgrade [1] and the ILC Program [2]. In particular, a significant increase in luminosity has to be considered. The present study has been based on the glass material BaO*2SiO2 (DSB) using different activators such as Ce or Gd ions. The production of various samples in different shapes takes advantage of optimized sintering processes and the established technology of glass production. We will report on test results of a large set of DSB samples with volumes of 1-2 cm3 as well as large size samples up to a length of 12 cm or thin fibers, respectively. The investigation has been focusing on light output, the scintillation kinetics, optical transmission and radiation hardness with respect to irradiations with a high dose due to gamma-rays or 150 MeV protons. [1] The CERN Large Hadron Collider: Accelerator and Experiments, Vol. 1-2, CERN, Geneva, 2009. [2] International Linear Collider Technical Design Report, Tokyo, Geneva, Chicago – 12 June 2013.

Speaker: Rainer Willi Novotny (Justus-Liebig-University)

S11-5a.pdf

S11-5a.pptx

S11-5b.pdf

S11-5b.pptx

BANQUET

Friday, 20 May

New concepts for calorimetry

Convener: DongHee Kim (Kyungpook National University)

75 Analysis of hadronic showers in the physics prototype of the CALICE silicon tungsten electromagnetic calorimeter - Si-W ECAL

**Introduction** The physics at future high-energy lepton colliders requires jet energy reconstruction with unprecedented precision. Detector concepts for the International Linear Collider (ILC) and the Compact Linear Collider (CLIC) rely on Particle Flow Algorithms to achieve the necessary precision. This event reconstruction technique requires highly granular calorimeters to deliver optimal performance. Such calorimeters are developed and studied by the CALICE collaboration. To develop realistic Particle Flow Algorithms, the interactions of hadrons must be modelled reliably in Monte Carlo simulations and the detector response to hadrons must be well-understood. Highly granular calorimeter prototypes provide a unique means to test and to further develop models of hadronic cascades. The response of the CALICE silicon-tungsten electromagnetic calorimeter prototype (Si-W ECAL) is used to test hadronic shower models at low energies. The depth of the Si-W ECAL corresponds to approximately one interaction length ($\lambda_\mathrm{I}$), which means that, although the complete shower is not recorded, the first hadronic interaction can be studied in great detail because of the fine longitudinal and transversal sampling. The Si-W ECAL was operated in a test beam at the Fermi National Accelerator Laboratory (FNAL) with negatively charged pions ($\pi^-$) in the energy of range 2 -- 10 GeV. The majority of charged pions and other hadrons within high energy jets have energies in this range and therefore it is of considerable interest to validate the performance of Monte Carlo simulations at these energies. **Studying the structure of the first hadronic interaction** The results of the study of global observables such as radial and longitudinal hit and energy distributions of hadronic showers, that has been published in *Nucl.Instrum.Meth. A794 (2015) 240-254* will be briefly recapitulated. As an extension of this analysis the contribution will present new results that become available due to the high granularity of the Si-W ECAL An algorithm has been developed to measure tracks in the Si-W ECAL, while permitting at the same time to characterise the interaction zone in terms of energy deposition and spatial extension. All observables studied in the analysis are thus very detailed probes of hadronic shower models. *The entire set of the results of this innovative study will be presented for the first time at the CALOR conference.* The analysis will compare the energy deposited in the interaction zone and the number of tracks that emerge from the interaction zone for different energies of the primary pion.  Preliminary results show that, as expected, the deposited energy and the number of tracks increase with the energy of the primary pion. However, the tested Monte Carlo models contained in GEANT4 are not able to reproduce the energy deposited in the first hard interaction. On the other hand track based observables are surprisingly well reproduced by the Monte Carlo Models. The secondaries that lead to measurable tracks interact in the Si-W ECAL in form of MIPs. As will be shown, the analysis is also a first step towards an in-situ calibration of the Si-W ECAL. In-situ calibration will be extremely useful to monitor the response of a full size Si-W ECAL in a Linear Collider experiment. Precise tracking in the Si-W ECAL is an indispensable premise for the application of Particle Flow algorithms to highly granular calorimeters. The successful seed of secondary tracks in the Si-W ECAL facilitates the reconstruction of tracks throughout the calorimeter system that will be completed by a hadronic calorimeter with depth of several interaction lengths. The comparatively simple tracking algorithm, as presented in this contribution, will allow to judge on the performance of more involved algorithms such as PandoraPFA or ARBOR.

Speaker: Roman Poeschl (Laboratoire de l'Accelerateur Lineaire (FR))

calor2016.pdf

76 DHCAL with Minimal Absorber: Measurements with Positrons

The CALICE Digital Hadron Calorimeter (DHCAL) is a highly-granular 1 m$^3$ large prototype, based on Resistive Plate Chambers (RPCs) with digital readout of 1$\times$1 cm$^2$ pads. In special tests, 50 of its active layers were exposed to low energy particle beams, without interleaved absorber plates. The thickness of each layer corresponded approximately to 0.29 radiation lengths or 0.034 nuclear interaction lengths, defined mostly by the copper and steel skins of the detector cassettes. The results of the measurements performed at the Fermilab test beam with positrons in the energy range of 1 to 10 GeV will be presented and compared to simulations based on GEANT4. It is found that the default GEANT4 simulation of electromagnetic showers is not able to reproduce the measurements of the energy resolution and the detailed shower shapes. With the use of the so-called 'Option 3' or '\_EMY' good to excellent agreement is obtained.

Speaker: Coralie Neubuser (Deutsches Elektronen-Synchrotron (DE))

CALOR_2016_Benjamin_Freund.pdf

77 Separation of nearby hadronic showers in the CALICE SDHCAL prototype detector using ArborPFA

A new reconstruction algorithm, ArborPFA, is developed to separate nearby 
hadronic showers in the SDHCAL prototype. This intends to demonstrate the capability of 
high granularity hadronic calorimeters such as the SDHCAL to efficiently apply Particle Flow 
Algorithms. The reconstruction algorithm we present here uses the tree-like structure features of hadronic showers, that high granular calorimeters reveal, to associate hits belonging to each hadronic shower and to reduce confusions between two close-by showers. The results of these studies indicate a good single particle efficiency and reconstructed energy. A powerful separation down to distances of 5 cm is obtained.

Speaker: Imad Laktineh (Universite Claude Bernard-Lyon I (FR))

ArborPFA_CALOR2016.pdf

78 Resistive Plate Chamber Digitization in a Hadronic Shower Environment

The CALICE Semi-Digital Hadron Calorimeter technological prototype that was completed in 2011, is a sampling calorimeter using Glass Resistive Plate Chamber detectors as the active medium. This technology is one of the two options proposed for the hadron calorimeter of the International Large Detector for the International Linear Collider. The prototype was exposed to beams of muons, electrons and pions of different energies at the CERN Super Proton Synchrotron. To be able to study the performance of such a calorimeter in future experiments it is important to ensure reliable simulation of its response. The SDHCAL prototype simulation, performed with GEANT4, and the digitization procedure will be presented. Comparisons between data and simulation on the SDHCAL response to muon tracks, electromagnetic and hadronic showers will be shown. First study using this calorimeter prototype on hadronic shower topology will be presented.

Speakers: Arnaud Steen (National Taiwan University (TW)), Imad Laktineh (Universite Claude Bernard-Lyon I (FR))

sdhcal-digit.pdf

79 A highly granular scintillator-based hadron calorimeter prototype with integrated readout

Within the CALICE collaboration, several concepts for the hadronic calorimeter of a future linear collider detector are studied. After having demonstrated the capabilities of the measurement methods in *physics prototypes*, the focus now lies on improving their implementation in *engineering prototypes*, that are scalable to the full linear collider detector. The Analog Hadron Calorimeter (AHCAL) concept is a sampling calorimeter of tungsten or steel absorber plates and plastic scintillator tiles read out by silicon photomultipliers (SiPMs) as active material. The front-end chips are integrated into the active layers of the calorimeter and are designed for minimal power consumption (power pulsing). The versatile electronics allows the prototype to be equipped with different types of scintillator tiles and SiPMs. In recent beam tests, a prototype with ~3700 channels, equipped with several types of scintillator tiles and SiPMs, was exposed to electron, muon and hadron beams. The experience of these beam tests as well as the availability of new generation SiPMs with much reduced noise and better device-to-device uniformity resulted in an improved detector design with surface-mount SiPMs allowing for easier mass assembly. The talk will discuss the AHCAL testbeam measurements, the improved detector design and plans for future prototypes and beam tests.

Speaker: Oskar Hartbrich (Deutsches Elektronen-Synchrotron (DE))

AHCAL_CALOR2016_2.pdf

10:10 Break

New concepts for calorimetry

Convener: Rainer Willi Novotny (Justus-Liebig-Universitaet Giessen (DE))

80 Comparison of Energy Reconstruction Schemes and Different Granularities in the CALICE Scintillator-Steel Analogue Hadron Calorimeter

The CALICE collaboration develops different high-granularity hadronic calorimeter technologies for a future linear collider. These technologies differ in active material, granularity and their readout and thus their energy reconstruction schemes. The Analogue Hadron Calorimeter (AHCAL), based on scintillator tiles with Silicon Photomultiplier readout, measures the signal amplitude of the energy deposition in the cells of at most 3$\,\times\,$3$\,$cm$^2$ size. The Digital, Resistive Plate Chamber (RPC) based, HCAL (DHCAL) detects hits above a certain threshold by firing pad sensors of 1$\,\times\,$1$\,$cm$^2$. A 2$\,$bit readout is provided by the, also RPC based, Semi-Digital HCAL (SDHCAL), which counts hits above three different thresholds per 1$\,\times\,$1$\,$cm$^2$ cell. All three calorimeter concepts have been realised in a 1$\,$m$^3$ prototype with interleaved Steel absorber and tested at various test beams. This study investigates the impact of the readout, granularity and active medium on the energy resolution individually by applying the reconstruction procedures on AHCAL data, that can also be processed in a way which emulates a (semi-) digital readout system. The difference in granularity is studied via simulations of an AHCAL with 1$\,\times\,$1$\,$cm$^2$ cell sizes. Additionally, a so-called Software Compensation algorithm is developed to weight hits dependent on their energy content and correct for the difference in the response to the electromagnetic and hadronic sub-showers ($\frac{e}{h}\neq1$) and thus reduce the influence of fluctuations in the $\pi^{0}$ generation. The impact on the energy resolution will be discussed and compared to the other energy reconstruction schemes.

Speaker: Coralie Neubuser (Deutsches Elektronen-Synchrotron (DE))

20160520_Calor16.pdf

81 Single pion energy resolution of a high granularity scintillator calorimeter system

Within the CALICE collaboration, several high granularity calorimeter prototypes optimised for particle flow reconstruction have been realised. One of the explored readout technologies consists of scintillating plastic elements read out by silicon photomultipliers (SiPMs), enabling unprecedented granularity in scintillator calorimeters. With this technology the ScECAL, an EM calorimeter with W absorbers and 45$\times$10mm${}^2$ strip readout, the AHCAL, a hadron calorimeter with steel absorbers and down to 30$\times$30mm${}^2$ tile segmentation, and the TCMT with steel absorbers instrumented with 50$\times$1000mm${}^2$ scintillator strips, have been realised. During the testbeam campaign in the MTest beamline at FTBF in 2009 the ScECAL, AHCAL and TCMT have been operated in muon, electron and pion beams in the momentum range of 1 to 32$\,$GeV/c. The detailed simulation model of the combined calorimeter system is validated with muons and electromagnetic showers. This talk will be the first public discussion of the single pion energy resolution of the setup in data and simulations, using both classical energy reconstruction as well as software compensation techniques.

Speaker: Oskar Hartbrich (Deutsches Elektronen-Synchrotron (DE))

2016_05_20_CALOR.pdf

82 Towards a technological prototype for a high-granularity electromagnetic calorimeter for future lepton colliders

A key ingredient to meet the requirements of the physics program at energy frontier machines such as future lepton colliders or the LHC are calorimeters with an unprecedented high granularity. These kind of calorimeters allow for the application of particle flow algorithms that rely on an excellent particle separation within the calorimeter. The R&D program comprises an electromagnetic calorimeter with tungsten with a radiation length $X_0=3.5$~mm, Moli\`ere radius $R_M=9$ mm and interaction length $\lambda_I=96$~mm as absorber material and silicon as the active material. French and Japanese groups within the CALICE collaboration are conducting an intensive program for the development of highly granular calorimeters. A physics prototype with a pixel size of $1 \times 1~{\rm cm^2}$ dedicated mainly to demonstrate the physics potential of a calorimeter has been successfully operated in the years 2005-2011. It has been proven that the pixelised silicon wafers are particularly suited to assure a high separation power while allowing at the same time a stable detector operation over a long time. These are reasons why this technology has been chosen for the upgrade of the forward calorimeters of the CMS experiment at the LHC.The technology is also studied for the upgrade of the ATLAS detector. The design of the (next) prototype for a silicon tungsten (SiW) electromagnetic calorimeter puts the emphasis on the understanding and overcoming of the engineering challenges imposed by the requirements on the detector compactness. The main units of the calorimeter prototype are: - The so called {\it alveolar structure} made of pre-impregnated carbon-fibre and epoxy which is also equipped with the tungsten absorber material. This alveolar structure has been fabricated during winter 2011/12 and is now subject to external mechanical studies including thermal tests. - Layers with a length of up to 1.5\,m that carries up to 8 Active Signal Units or ASUs which is the entity of four silicon wafer, PCB and readout electronics. An ASU features a lateral dimension of $18 \times 18~{\rm cm^2}$ each and in the most aggressive design a height of about 2\,mm. It comprises 1024 cells read out by 16 ASICs. In an initial phase with ASUs carrying only one wafer and four ASICs have been tested that allowed for example to validate the concept of embedded electronics. We have now turned to the production of several fully equipped ASUs that undergo validation in beam tests and on test benches. In both cases the flexible and in many parts scalable data acquisition system will be used. The presentation will report on first results of this validation but will also sketch the main steps of the involved production process that is part is supported but the European AIDA-2020 and since recently by the French excellence programme P2IO. Both programmes seek explicitly to foster synergies between the necessary R&D programs for CALICE, ATLAS and CMS. An overview on synergies is thus part of the proposed contribution for the CALOR conference. The contribution will finally report on the R&D programme on silicon wafers and on irradiation tests carried out in 2015 at Japanese irradiation facilities.

Speaker: Taikan Suehara (Kyushu University)

suehara-calor.pdf

83 The SDHCAL prototype status: present end future

The successful running of the technological prototype of the Semi-Digital Hadronic CALorimter (SDHCAL) proposed to equip the future ILD detector of the ILC has provided excellent results in terms of energy linearity and resolution and also tracking capabilities. Stability with time of the prototype is also successfully tested. To validate completely the SDHCAL option for ILD, a new R&D activities have started. The aim of such activities is to demonstrate the ability to build large detectors (> 2m2). The construction of efficient detectors of such a size necessitates additional efforts to ensure the homogeneity and the efficiency of these large detectors. Another important point of the new activities is to use a new version of the HARDROC ASIC that was used in the prototype with success. The new version has several advantages with respect to the one used in the SDHCAL prototype such as the zero suppression and the I2C protocol. Another development is the DAQ electronic board. A new one is proposed. In addition to a reduced size to cope with the ILD requirements, new features are being implemented. A TCP/IP protocol is adopted in the new card to ensure the coherency of the data transmission. The TTC protocol is also to be used to distribute the clock to the different ASIC on the electronic board. The new DAQ board is being conceived to have the capability to address up to 432 ASICs of 64 channels each. Designs for both the DAQ board and the electronic boards are being finalized and the first boards will be produced soon while 600 of the new HARDROC were produced and tested. A new cassette, to host the active layer while being as before a part of the absorber, is being also conceived. The challenge is to maintain a good rigidity to ensure the perfect contact between the electronic board and the GRPC and also to facilitate the dissipation of the ASIC heating. Finally, the mechanical structure of the new prototype will use a new welding technique to reduce the dead zones and provide less deformed structure. Few attempts using the electron beam welding technique to build small setup have been realized at CERN.

Speaker: Imad Laktineh (Universite Claude Bernard-Lyon I (FR))

SDHCAL-Daegu-CALOR2016.pdf

SDHCAL-Daegu-CALOR2016.pptx

84 Closing Remarks

Speaker: HongJoo Kim (Kyungpook National University)

85 Comments from the International Advisory Committee

Speaker: Nural Akchurin (Texas Tech University (US))

86 Invitation to CALOR 2018

Speaker: Jim Brau (University of Oregon (US))

CALOR18_Oregon.pdf