The MIP Timing Detector (MTD) of the Compact Muon Solenoid (CMS) is designed to provide precision timing information (with resolution of ~40 ps) for charged particles as part of the Phase II upgrade program to prepare for the HL-LHC. The endcap region of MTD, called the Endcap Timing Layer (ETL), will cover the high radiation pseudo-rapidity region between |η|=1.6 and 3.0. The ETL will be...
A High Granularity Timing Detector (HGTD) is proposed for the ATLAS detector upgrade for the high luminosity LHC phase where the pile-up is expected to increase on average to 200 interactions per bunch crossing. The detector will be in front of the liquid Argon end-cap calorimeters for pile-up mitigation and for bunch per bunch luminosity measurements. Two Silicon sensors double sided layers...
In this contribution, I will present the data currently available on the effects of temperature and irradiation on the gain mechanisms of LGAD. The data currently available regard both the multiplication mechanism in the bulk and in the gain layer. From these measurements, a model of the behavior of future LGAD productions vs temperature and fluence can be established.
For the high luminosity LHC or Phase-II operation, the ATLAS and CMS experiments are planning to include especial detector in order to perform timing measurements of minimum ionizing particles (MIPs). Both detector will be exposed to a radiation levels up to 3E15 neq/cm2 and will required a timing performance of about 30 ps. Under these circumstances, Low Gain Avalanche Detectors (LGADs) are...
This contribution is focusing on two main topics in UFSD characterization: uniformity of gain in a UFSD productions and effect of the irradiation on these sensors.
In the first part of this contribution I will report on the measurements of the gain layer uniformity performed on UFSD sensors manufactured by Hamamatsu Photonics (HPK) and by Fondazione Bruno Kessler (FBK).
The second part of...
Profiting from our internal silicon-dedicated clean-room facility, we developed an LGAD technology in-house. We fabricated single pads and arrays of pads on several 50-um thick p-type epitaxial wafers. The wafers differ for the implantation parameters (i.e., energy and dose) of the gain-layer, resulting in the achievement of gains in a wide range. We attain maximum gains in the order of 25,...
The first LGAD sensors designed and fabricated in China have been evaluated including the basic electrical properties as well as timing properties. The status of the planned proton irradiation in China will also be presented. In addition, the joint project to produce Schottky diodes on epitaxial silicon for radiation damage study will be introduced.
In this contribution we will show the latest results from laboratory measurements of Low-Gain Avalanche Diodes (LGADs) from a common AIDA-2020 run fabricated by CNM. These sensors come in two different thickness ( 50 and 35 µm) and different gain layer doping concentrations. The test setup used for this studies consist of a Sr-90 source and couples of identical sensors aligned to form a...
The third production of Ultra Fast Silicon Detectors (UFSD3) from Fondazione Bruno Kessler (FBK) and Low Gain Avalanche Detectors (LGADs) from Hamamatsu Photonics K.K. (HPK), produced for CMS, include 2x2 sensors with different structural strategies, specifically with different values of narrower inactive region widths between the pads. These sensors have been designed to study specific...
Low gain avalanche detectors (LGADs) are currently the state-of-the-art silicon detectors for timing application in HEP experiments. One limitation of the current technology is the relatively wide dead region present between pixels (40-60 µm), which reduces the effective fill-factor and the efficiency of the sensors and might limit some applications in which finely segmented detectors are...
Low Gain Avalanche Diodes provide excellent timing capabilities with moderate radiation resistance for HL-LHC applications. Segmented LGADs (microstrips or pixels) implement the amplification layer below the electrodes, leading to non-uniform gain across the surface of the detector. This is the so-called "filling factor" problem. A possible way to achieve uniform amplification is by moving the...
In this contribution we explore the recent results coming from the first RSD (Resistive AC-Coupled Silicon Detectors) production run at Fondazione Bruno Kessler. After reviewing the design, layout and technology related to the resistive AC-coupled readout paradigm, we present some static and dynamic characterizations of our detectors before irradiation, along with extensive comparisons between...
At the end of LHC Run II fluence in silicon trackers reached the level 10e15 1MeV neq/cm2. Comparison of prediction with measurements showed some discrepancies between experiments which may be driven by differences in tools used for the simulation. In this study, we compared two physics models: Pythia 8.2 and DPMJET3 used for the fluence simulation in Fluka package for geometry of the typical...
Silicon detectors were irradiated with with reactor neutrons up to very high fluences of 3e17 n/cm2. First results of measurements at these fluences were shown at the 32nd RD50 workshop. New charge collection measurements with Sr-90 source and new E-TCT measurements will be presented in this contribution.
Pixel detectors, made of Si and CdTe, were characterized by raster scanning the detector surfaces with laser-TCT setup. The detectors were manufactured using aluminum oxide (Al$_2$O$_3$) thin films grown by atomic layer deposition (ALD) as dielectric and field insulator. From the TCT-maps we measure signal shaping within the bulk, locate defects, and evaluate their impact to the charge...
We present preliminary results of the TID bulk damage study in gamma-irradiated n-in-p silicon strip sensors.
The sensors were irradiated by a high-flux 60Co gamma rays up to a total dose of 300 Mrad in approximate charged particle equilibrium.
The study was performed on high-rho silicon sensors with initial resistivities of 4 and 17 kOhmcm.
The properties of sensors were characterized...
A new proton irradiation site for NIEL damage studies is currently being developed at the Bonn isochronous cyclotron of the HISKP. Irradiations with a proton energy of 12.7 MeV at device location and currents up to 1 uA are possible. A unique feature of the site is the newly installed beam-diagnostics system. It allows the determination of the proton fluence at percent level and can be used as...
CiS has started various projects to develop detectors for the detection of UV / DUV, X-ray, neutrons, low energy electrons, alpha and beta particles, prompt-gamma detection and Delta-E detectors.
This requires amongst others extremely flat pn junctions with sufficient sheet resistance even for larger areas and thinnest dead layers.
Technological methods, such as Plasma Immersion Ion...
Low Gain Avalanche Detectors (LGAD) are part of family of Avalanche Photodiodes but have only small gain of an order of magnitude. LGAD’s have been shown to have a very fast response time, order of picoseconds, which can make them useful in many applications, including concurrent excellent time and position resolution tracking for particle physics and synchrotron applications.
In this work we...
We present a program for fast calculation of capacitances in planar silicon pixel (strip) sensors, based on a 3D (2D) numerical solution of the Laplace equation. A comparison between calculated capacitances and measurements on silicon strip sensors, along with simulation results obtained with the TCAD Sentaurus suite are presented. The validity of 2D calculations is checked with measurements...
The understanding of the weighting field of irradiated silicon sensors is essential for calculating the response of silicon detectors in the radiation environment at accelerators like at the CERN LHC. Using 1-D calculations of non-irradiated pad sensors and 1-D TCAD simulations of pad sensors before and after irradiation, it is shown that the time-dependence of the weighting field is related...
Garfield++ is a toolkit for the detailed simulation of particle detectors based on ionization measurement in gases or semiconductors. After a brief introduction to the program, ongoing work on the implementation of the simulation of induced currents using time-dependent weighting fields is presented.
This contribution describes design work within the CERN-RD50 collaboration to develop depleted CMOS sensors in the 150 nm HV-CMOS (High Voltage-CMOS) process from LFoundry. In particular, we will present the design details of a test chip, named RD50-MPW2, which was submitted for fabrication in January 2019. We will also present the design towards a new pixel flavour, known as a sampling pixel,...
We will present latest results of dark current (I-V) and charge collection efficiency (CCE, obtained using a calibrated laser source) of OVERMOS, a high resistivity TJ 180nm CMOS MAPS, irradiated with neutrons up to 1e15 cm-2 fluence. Results of charge collection within the 40 x 40 um2 pixel region,with 5um resolution, and charge collection time will be shown.
Test results are compared with...
The MIDAS device is an active dosimeter for application in the mixed field of space environment under development. It will use active pixel sensors for the measurement of energy depositions by charged particle tracks in Si pixel layers covering five out of six faces of a plastic scintillator cube. The Si active pixel sensors are based on commercial High Voltage CMOS technology which has proven...
This contribution will describe the last developments carried out and the ones foreseen for the characterization of the RD50 MPW1 and RD50 MPW2 depleted monolithic pixel sensors implemented in the LFoundry 150 nm technology in the framework of the RD50 collaboration. A modular and scalable DAQ system is being developed for this purpose and for other possible applications in the future...
TCT measurements have been performed on the H35DEMO chip, a HV-CMOS sensor produced by ams in H35 350 nm technology, before and after proton and neutron irradiation. The proton irradiation has been performed at the Bern Inselspital cyclotron (18 MeV) and at the Proton Syncrotron at CERN (24 GeV) up to more than $10^{15}$ 1 MeV $n_\mathrm{eq}/\mathrm{cm}^2$. The neutron irradiation has been...
The LF2 is a depleted MAPS prototype chip produced in 2018 in the LFoundry 150 nm HV-CMOS process by the collaboration of IFAE, University of Liverpool, University of Geneva and KIT with the support of RD50.
The chip includes two monolithic matrices which are completely independent and only share the substrate: a tracking pixel detector and a photon counting device.
The main components of...
