VFAT3 is a front-end ASIC designed for the readout of GEM detectors in the CMS Muon system. The strategy for the chip design was to design the full chip at once but provide extensive test and debug ...facilities for individual characterization of each internal chip module. The verification platform consists of three parts; namely the software (running on a PC), the firmware (designed for a Kintex-7 FPGA development board) and a selection of VFAT3 dedicated hardware boards for the different stages of verification. The system was designed to accommodate all of the steps needed to fully test the chip. The first step is the functional testing for which only rather simple functions are needed. For the functional testing. the software has an interactive interface to communicate with the chip through the FPGA. The requirements for the hardware are mostly the possibility for the use of the main communication channels. For the characterization of the chip, the software offers a possibility to easily generate lists of routine instructions that can be uploaded to the FPGA and run as synchronous commands. This allows for example the scanning of the chip's internal calibration DACs and creation of S-curves for all of the front-end channels. The hardware boards of the system allows access to the vast amount of test pads needed for the characterization and debug of the chip. The production tests require concatenated test routines where speed and execution efficiency are crucial. The software and the firmware of the system were designed to allow flexible evolution to increase the efficiency of complicated test routines.
GEM based detector for future upgrade of the CMS forward muon system Abbaneo, D.; Armagnaud, C.; Abbrescia, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2013, Letnik:
718
Journal Article
Recenzirano
In view of an upgrade of the CMS experiment, the GEM for CMS collaboration is performing feasibility studies on employing Triple-GEM detectors for the high-η region (1.6–2.4) of the CMS endcaps. A ...detailed review of the development and characterization of the CMS full-size prototype baseline detector will be presented. GEMs have excellent spatial and time resolution, high rate capability and radiation hardness, they are an appealing option for simultaneously enhancing muon tracking and triggering capabilities in the high-η region. The GEM for CMS collaboration has studied the performance of small and full-size prototype detectors during several test beam campaigns in order to validate new technologies and techniques in view of a mass production for CMS experiment. Results from measurements with x-rays and from test beam campaigns at the CERN SPS will be shown from both small and large prototypes.
The status of the GEM project for CMS high-η muon system Abbaneo, D.; Abbrescia, M.; Armagnaud, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2013, Letnik:
732
Journal Article
Recenzirano
Odprti dostop
The dedicated CMS R&D program was intended to study the feasibility of using micropattern detectors for the instrumentation of the vacant |η|>1.6 region in the present Resistive Plate Chambers (RPCs) ...endcap system. The proposed detector for CMS is a Triple-Gas Electron Multiplier (GEM) trapezoidal chamber, equipped with 1D readout. While during 2010–2011 the Collaboration worked on the prototyping of the detector, during the first part of 2012 a newly developed assembly technique to be used for the mass production was adopted. GEMs can provide precision tracking and fast trigger information, contributing on one hand to the improvement of the CMS muon Trigger and on the other hand to provide the missing redundancy in the high η region. In the view of the next LHC long shutdown (LS1) the CMS GEM Collaboration designed and built four full-size Triple GEM-based muon detectors.
A Time Projection Chamber (TPC) is a candidate for the central tracker of the future International Linear Collider (ILC) detectors. TPCs have already demonstrated very good performance in past ...collider experiments. In order to obtain one order of magnitude improvement in momentum resolution and the highest possible track recognition efficiency, the Linear Collider TPC (LCTPC) Collaboration is pursuing R&D activities to find the best state-of-the-art technology for the TPC. According to the ILD Letter of Intent, the TPC will have a diameter of 3.6 m and a length of 4.3 m. It should provide 200 space points with pad readout along a particle track, with a spatial resolution of 100 ¿m in the R¿ plane. To achieve these performances, a TPC equipped with Micro Pattern Gaseous Detectors (MPGD) instead of Multiwire Proportional Chambers (MWPC) is needed. Therefore the LCTPC Collaboration has built a large TPC prototype (LPTPC), with a diameter of 750 mm and a length of 600 mm, which can be equipped with Micromegas or GEMs as amplification structures. Since the end of 2008, the LPTPC has been exposed during several weeks to an electron beam of up to 6 GeV at DESY, in presence of a magnetic field of up to 1.0 Tesla. The LPTPC is not only a testing bed for several readout techniques based on MPGDs it is also a unique opportunity to understand the issues which arise when constructing such a large TPC. In this note we will report on the production and the commissioning of the LPTPC as well as the first results of the test beams.
High rate behavior and discharge limits in micro-pattern detectors Bressan, A; Hoch, M; Pagano, P ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/1999, Letnik:
424, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We present and discuss a set of systematic measurements, carried out with gaseous proportional micro-pattern detectors, in order to assess their maximum gain when irradiated with high-rate soft ...X-rays and heavily ionizing alpha particles. The inventory of detectors tested includes: micro-strips, micromegas, micro-dot, gas electron multiplier, CAT (compteur à trous), trench (or groove), micro-CAT (or WELL) detectors, as well as systems with two elements of gaseous amplification in cascade. We confirm the general trend of all single-stage detectors to follow Raether's criterion, i.e. a spontaneous transition from avalanche to streamer, followed by a discharge, when the avalanche size reaches a value of a few 10
7; a noticeable exception is the micro-dot counter holding more than 10
8. In multiple structures, where the gain is shared between two devices in cascade, the maximum overall gain under irradiation is increased by at least one order of magnitude; we speculate this to be a consequence of a voltage dependence of Raether's limit, larger for low operating potentials. Our conclusion is that only multiple devices can guarantee a sufficient margin of reliability for operation in harsh LHC running conditions.
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