The presentation will deal with the numerous irradiation tests performed before the construction of
the ATLAS Big-Wheels (BW) TGC’s, as well as irradiation tests performed before the construction of
the New Small Wheel (NSW) sTGC’s. The results achieved by following the charge deposited by MIP’s
in each individual detector plane after 11 years of operation will be shown. A presentation...
The muon detector of LHCb, which comprises 1368 multi-wire-proportional-chambers (MWPC) for a total area of 435 m2, is the largest instrument of its kind exposed to such a high-radiation environment. In nine years of operation, from 2010 until 2018, we did not observe appreciable signs of ageing of the detector in terms of reduced performance. However, during such a long period, many chamber...
The LHCb experiment is designed to study B-decays at the LHC, and as such is constructed as a forward spectrometer. The large particle density in the forward region poses extreme challenges to the subdetectors, in terms of hit occupancies and radiation tolerance.
To accurately and efficiently detect the charged decay particles in the high-density particle environment of the LHC the Outer...
Gaseous Detectors and Radiation Hardness: challenges and requirements from the next generation of experiments
Large size hybrid Micromegas gaseous detectors (40x40 cm² active area) were developed and installed in 2015, in view of the COMPASS2 physics program which started that year. That program involved in particular two years of Drell-Yan studies based on a high intensity pion beam on a thick polarized target. Although the detectors were placed behind an thick absorber, they were exposed to...
The MicroBooNE experiment is a Liquid Argon Time Projection Chamber (LArTPC) placed along Booster Neutrino Beam (BNB) at Fermilab. MicroBooNE ran its physics and R&D runs from 2015 through 2021. Its primary physics goal is to contribute to addressing the elusive short-baseline MiniBooNE low energy excess. MicroBooNE records and utilizes both the ionization charge and scintillation light...
The high counting rate MSMGRPC (Multi – Strip, Multi-Gap Resistive Plate Chamber) prototypes developed for the CBM experiment at FAIR, operated with C_2H_2F_4 and SF_6 based gas mixtures, showed in laboratory cosmic -ray tests a very good performance. Later on, the obtained results were confirmed in the in-beam tests with reaction products, in the high counting rate test the efficiency...
The GEM detectors with pad readout have been installed in the Muon apparatus of the LHCb experiment, more precisely in the innermost region (R1) of the first muon station (M1) . The GEM detectors have been operated with Ar/CO$_2$/CF$_4$=45/15/40 gas mixture at a gain of about 4000 with an average particle flux of about 200 kHz/cm$^2$. During the RUN1 and RUN2, corresponding to about 440 days...
The LHCb experiment is designed to study B-decays at the LHC, and as such is constructed as a forward spectrometer. The large particle density in the forward region poses extreme challenges to the subdetectors, in terms of hit occupancies and radiation tolerance.
To accurately and efficiently detect the charged decay particles in the high-density particle environment of the LHC the Outer...
CMS CSC is a particular kind of Multi-Wire Proportional Chambers, or MWPC. Operation principle of MWPC is based on avalanche amplification of the primary charge in vicinity of a thin anode wire. The regions of avalanche development are microscopic areas of plasma, and plasma chemical reactions may lead to formation of deposit on the electrode surfaces of the MWPC, causing degradation of its...
Detector stability and Discharges in GEM
The MEG experiment (phase 1) at the Paul Scherrer Institute, searching for the charged lepton flavor violating decay mu -> e + gamma, took physics data from 2009 until 2013. The analysis of the combined data sample resulted in an upper limit of 4.2∙10E{-13} (90%CL) on the branching ratio that is still the most stringent limit on this decay to date.
The drift chamber system was designed to...
The NSW Micromegas chambers in the ATLAS forward muon
spectrometer are subject to background rates of 15-20 kHz/cm$^2$
under HL-LHC conditions.
Typical anode currents will be around 6 $\mu$A on an area of 1440 cm$^2$
in the innermost part closest to the beamline.
Due to the late change of the detectorgas from non-ageing Ar:CO2 93:7
to the more HV stable ternary mixture Ar:CO2:isobutane...
As part of the high-luminosity LHC (HL-LHC) upgrade, the CMS muon spectrometer will extend its coverage in the very forward region with triple-GEM detectors. These detectors will cope with a harsh environment with expected background fluxes up to 150 kHz/cm^2. At the end of HL-LHC operation, the total accumulated charge at the hottest point is expected to reach 7.9 C/cm^2. This accumulated...
The High Luminosity LHC (HL-LHC) program will pose a great challenge for the CMS Muon System. Existing subdetectors, which consist of Drift Tubes (DT), Resistive Plate Chambers (RPC) and Cathode Strip Chambers (CSC), will have to operate at 5 times larger instantaneous luminosity than the designed for, and, consequently, will have to sustain about 10 times the original LHC integrated...
Aging Validation Setup at CERN
The ALICE Muon IDentifier is composed by 72 single gap bakelite Resistive Plate Chambers, which have been operational since 2009 in maxi-avalanche mode (discrimination threshold:7 mV without amplification) with a tetrafluoroethane/isobutane/sulfur hexafluoride gas mixture, undergoing counting rates of the order of tens of Hz/cm^2.
In this talk, the long-term performance and stability of...
540 Cathode Strip Chambers (CSC), a type of multi-wire promotional chamber, provide precise measurements of muon track coordinates in the CMS endcap region (pseudorapidity: 0.9-2.4) In the HL-LHC lifespan the CSC performance might degrade, in a process often called “aging”, due to the unprecedented high radiation dose. To this end, the CSC group has been conducting irradiation tests at the...
Resistive Plate Chambers (RPCs) are widely used in high-energy physics experiments because of their excellent ability to cover large detection areas with high particle detection efficiency and good time resolution. Often these properties are achieved by RPC detectors when they are operated with Freon-based gaseous mixtures that cause high global warming potential (GWP). Therefore, in order to...
The future fixed target high-rate Compressed Baryonic Matter (CBM) experiment is one of the experimental pillars of the Facility for Antiproton and Ion Research (FAIR) located in Darmstadt/Germany. Since CBM aims to operate at an interaction rate of up to 10 MHz for Au+Au collisions radiation hard and high rate capable detector have to be installed. In order to provide an excellent particle...
Like other gaseous technologies, GEM detectors can experience premature aging when operating in high-rate environments. This occurs when gas molecules dissociate and recombine within the plasmas generated during electron amplification, leading to the formation of large and complex polymers. These polymers can be deposited on the amplification structure and significantly impact the performance...
GEM-based detectors are widely used in High Energy Physics (HEP) environments due to their inherent resistance to classical aging. Their unique design, which spreads charge amplification across multiple GEM holes and layers, effectively reduces the local plasma energy responsible for polymer formation, a major cause of detector aging. Consequently, GEM detectors are particularly advantageous...
Aging of Photocathodes and Exploration of Novel PC materials
China Spallation Neutron Source (CSNS) is a large-scale scientific facility which is a source of high-flux pulsed neutrons. It contains a 80 MeV linear proton accelerator, a 1.6 GeV rapid cycling synchrotron, a target station, and a suite of modern neutron instruments mainly for application to neutron scattering, imaging, and other kinds of neutron science research to promote high-level...
Resistive electrodes are used in gaseous detectors to quench spark discharges. This helps to protect delicate electrodes and readout electronics and to improve the stability of the detector operation. An RPWELL is a THGEM-based WELL detector with a resistive plate coupled to a conductive anode. Till now, the choice of the resistive plate was limited to a few materials, like LRS Glass and...
Gaseous Ring Imaging Cherenkov (RICH) detectors are the natural choice to perform hadron identification at high momenta; they require efficient and accurate detection of single Cherenkov photons over large surfaces. MPGD detectors of single photons are sensitive in the vacuum ultraviolet (VUV) domain. In present, CsI is the only photoconverter adequate with gaseous detector due to its wide...
The ATLAS muon spectrometer will face an increase of particle rate, specially at high rapidity, consequently of the larger instantaneous luminosity for the HL-LHC phase, expected to attain 5x10$^{34}$ cm$^{−2}$s$^{−1}$.
The New Small Wheel (NSW) of the ATLAS muon spectrometer endcap is equipped with small-strip Thin Gap Chambers (sTGC) and Micromegas (MM), able to provide good tracking and...
Study of the gaseous detectors longevity is essentially important in view of the future LHC upgrade into the High Luminosity mode. Longevity and performance of two Cathode Strip Chamber types, different in design and experiencing the highest backround level at CMS, are being studied at the Gamma Irradiation Facility (CERN).
The irradiation started in 2016 and now the accumulated charge per...
The present Compact Muon Solenoid (CMS) Resistive Plate Chambers (RPC) system has been certified for 10 years of Large Hadron Collider (LHC) operation at a maximum background rate of 300 Hz/cm^2 and integrated charge of 50 mC/cm^2. In the next years, during the Phase 2 of the LHC physics program, called High Luminosity LHC (HL-LHC), the accelerator will increase the instantaneous luminosity up...
Discharge Stability and Resistive Structures
Two 50 cm long protype sMDT drift tubes have been irradiated using
beta-electrons from ^{90}Sr-^{90}Y decays with end point energy of 2.28 MeV.
Over two periods of 100 days and 125 days, respectively, the tubes were drawing
constant currents of 3 uA and 1.25 uA. Regions of approximately 10 cm of
the wires were irradiated intensively. Almost 40 C of charges have
been accumulated in...
The MEG II experiment searches for the $\mu\to e\gamma$ decay which is charged lepton flavor violating process. A new type of resistive plate chamber (RPC) using diamond-like carbon (DLC) electrodes is under development for the identification of gamma ray from the radiative muon decay background, in the MEG II experiment. In order to identify the background, low energy positrons on the muon...
The interest in using visible and near-infrared scintillation in Gas Electron Multipliers (GEMs) in experimental approaches based on optical readouts has grown recently. One gas mixture used for this purpose includes CF$_4$, which is known to cause etching in the interior walls of the GEM holes [1]. One question may arise: Where will this etched material be re-deposited? The question is...
Resistive Plate Chamber detectors at the CERN LHC experiments use a Freon-based gas mixture containing R-134a and SF6, high global warming potential greenhouse gases. To minimise greenhouse gas emissions and expenses and optimise RPC performance, it is crucial to research new environmentally friendly gas mixtures. Thus, according to CERN's environmental strategies and European regulations,...
Resistive Plate Chambers (RPCs) are gaseous detectors widely used in high energy physics experiments, operating with a gas mixture primarily containing Tetrafluoroethane (C$_2$H$_2$F$_4$), commonly known as R-134a, which has a global warming potential (GWP) of 1430. To comply with European regulations and explore environmentally friendly alternatives, the RPC EcoGas@GIF++ collaboration,...
In the context of particle physics, different families of gaseous detectors are operated with fluorinated-gases for different purposes. It is well known that under the effect of high electric field and radiation, fluorinated molecules may break and form, among other species, free fluorine ions. Such ions may react with water molecules present in the gas, leading to the formation of highly...
In the context of climate change, one of the main contributors to global warming is the greenhouse effect. Regulations have been implemented in different areas of society to reduce or ban the use of greenhouse gases, such as freon. Despite the fact that large-scale experiments (such as the ones held at CERN) have been excluded from these restrictions, as a scientific community, we have the...
The standard gas mixture for the Resistive Plate Chambers (RPC), composed of $\rm{C_{2}H_{2}F_{4}/i-\rm{C_{4}H_{10}/SF_{6}}}$, allows the detector operation in avalanche mode, as required by the high-luminosity collider experiments. The gas density, the low total charge delivered inside the gas and the comfortable avalanche-streamer separation guarantee high detection efficiency, rate...
Cathode Strip Chambers (CSC) are used for precise measurements of muon track coordinates in the CMS endcap region. CMS CSCs operate with 40%Ar+50%CO2+10%CF4 as a working gas mixture, where the CF4 component provides reliable protection against anode wire aging sufficient for operation during the HL-LHC period. However, CF4 has a Global Warming Potential (GWP) of 6630 over 100 years, and is...
Recent advancements in active target detectors, enabling the detection gas to act as a target for nuclear reactions, have provided a significant boost to the exploration of nuclei near the drip lines and the exotic nuclear phenomena associated with them. ACTAR-TPC at GANIL is a novel detector of such kind that can construct a 3-D mapping of the decay or reaction products from two-dimensional...
In the CERN CMS experiment, CSC detectors are employed and operated with a gas mixture based on CF4. Since 2016, two Single Wire Proportional Chambers (SWPCs) have been installed along the gas line to monitor the quality of the gas. The first SWPC was positioned immediately after the gas mixer unit, while the second was placed within the gas loop. SWPCs exhibit a high sensitivity to the...
The expected limitations on the use of HFCs and other fluorinated gases motivated the opening of a new line of R&D in RPCs: sealed RPCs. This approach requires only very low amounts of gas and dispenses with the very complex and expensive recirculation and/or recycling gas systems.
At the moment it is not clear if this solution can cover all the fields of application of RPCs, but it seems...
At low energy frontier among the Standard Model testing methods and searches for new physics beyond it are precision spectrum shape and correlation coefficient measurements in nuclear and neutron beta decay. For identification and 3D-tracking of low-energy electrons a special type of gas-based detector was designed that minimizes scattering and energy loss. In the first approach the gas...
The ongoing work on the development and testing of a prototype of a Micromegas (MM) detector and its front end electronics will be presented. Presently a revision of the front-end electronics with a new discharge protection circuit is being tested and results will be discussed. Moreover, a first insight on the development of a new ASIC for the MM readout will be provided.
For the AMBER (NA66)...
The study of nuclear fission is integral to the fundamental understanding of nuclear physics and it has significant implications in many sectors, such as energy generation, space research, and radioisotope synthesis for medical uses. With the VAriable MOde Spectrometer (VAMOS++) facility, at Grand Accélérateur National d'Ions Lourds (GANIL), we are exploring the nature of nuclear fission...
Thanks to a tool specially developed for that, we measured Paschen curves with real resistive Micromegas electrodes, both real mesh and real resistive anode layer. The resistive Micromegas structure and geometry studied correspond to those of the New Small Wheel (NSW) detector upgrade project of the ATLAS experiment at CERN.
Also these Paschen curves have been obtained for different gas...
Resistive Plate Chamber (RPC) detectors in the Compact Muon Solenoid (CMS) experiment operate with a gas mixture comprised of 95.2% of C2H2F4, that provides a high number of ion-electron pairs, 4.5% of iC4H10, that ensures the suppression of photon-feedback effects and 0.3% of SF6, used as an electron quencher to further operate the detector in streamer-free mode. C2H2F4 is known to be a...
The advancement of accelerator technologies helps the High Energy Physics (HEP) community to reach higher collision rates to measure rare physical observables with unprecedented precessions. This imposes a great challenge to the rate handling capabilities of the detectors. In the HEP experiments, gas-filled detectors are commonly used for tracking, triggering, and timing measurements. Gas...
Yttrium oxide thin films are deposited using indigenously developed metal organic precursor (2,2,6,6-tetra methyl-3,5-hepitane dionate) yttrium, commonly known as Y(thd)3 (synthesized by ultrasound method). Microwave electron cyclotron resonance plasma assisted metal organic chemical vapor deposition process was used for these depositions. Depositions were carried out at a substrate...
In the context of climate change, one of the main contributors to global warming is the greenhouse effect. Regulations have been implemented in different areas of society to reduce or ban the use of greenhouse gases, such as freon. Despite the fact that large-scale experiments (such as the ones held at CERN) have been excluded from these restrictions, as a scientific community we have the duty...
Plasma Chemistry (molecular dynamics) and Aging Effects
The GEM project of CMS encompasses the development, construction, and operation of three new triple-GEM detector systems, GE1/1, GE2/1 and ME0, for the upgrade of the forward muon spectrometer. The development of these systems and the operation of multiple advance-design demonstrators installed in the experiment, allowed for thorough studies of the gas breakdown effect that typically leads to...
Aging and stability of gaseous ionization detectors are intricately related to charging up, accumulation of space charge and formation of discharges. All these phenomena, in their turn, depend on the dynamics of charged particles within the device. Because of the large number of particles involved and their complex interactions, the dynamic processes of generation and loss of charged...
Since July 2022, GE1/1, the first station using Gas Electron Multiplier (GEM) technology in the Compact Muon Solenoid (CMS) experiment, has been participating in the data-taking in proton-proton collisions. This station is the first of three (GE1/1, GE2/1 and ME0) planned to be installed in CMS, to cope with the challenging conditions given by the upgrade of luminosity of the Large Hadron...
The sPHENIX experiment is currently under commissioning at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab (BNL). The Time Projection Chamber (TPC) serves as a tracking detector for the experiment. The sPHENIX TPC uses a stack of four Gas Electron Multipliers (GEM’s) as a gain stage in a reduced ion back-flow configuration. In non-ideal conditions, the high voltage across...
