Progress towards a THGEM-based detector of single photons Alexeev, M.; Birsa, R.; Bradamante, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Volume:
639, Issue:
1
Journal Article
Peer reviewed
The novel and robust Thick GEM (THGEM) electron multiplier, coupled to a solid state photon converter, represents a promising option for instrumenting, at affordable costs, large areas with photon ...detectors, in particular, in Cherenkov imaging counters where single photons must be detected with high efficiency. The main goal of our project is to demonstrate the feasibility of reliable gaseous detector of single photons based on the use of THGEM multipliers, able to stably operate at high gain and high rate and to build and validate a large size prototype of such a detector. The project status and perspectives are reported; in particular attention is dedicated to the simulation and laboratory studies performed to understand the photo-electron extraction performance attainable using a solid state coated photo-cathode film onto a THGEM substrate.
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New photon detectors, based on the use of multi-anode photo-multiplier tubes coupled to individual lens telescopes and read out with a dedicated read-out electronics system, equip the central region ...of the Cherenkov imaging counter RICH-1 of the COMPASS experiment at CERN SPS. They are characterised by high photon yield, fast response and high rate capability and are successfully in operation since the 2006 COMPASS data taking. The photon detection system fully matches the expected performance.
The design and construction of the photon detectors are described in detail.
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13.
Social norms as solutions Nyborg, Karine; Anderies, John M.; Daimenberg, Astrid ...
Science (American Association for the Advancement of Science),
10/2016, Volume:
354, Issue:
6308
Journal Article
Peer reviewed
Climate change, biodiversity loss, antibiotic resistance, and other global challenges pose major collective action problems: A group benefits from a certain action, but no individual has sufficient ...incentive to act alone. Formal institutions, e.g., laws and treaties, have helped address issues like ozone depletion, lead pollution, and acid rain. However, formal institutions are not always able to enforce collectively desirable outcomes. In such cases, informal institutions, such as social norms, can be important. If conditions are right, policy can support social norm changes, helping address even global problems. To judge when this is realistic, and what role policy can play, we discuss three crucial questions: Is a tipping point likely to exist, such that vicious cycles of socially damaging behavior can potentially be turned into virtuous ones? Can policy create tipping points where none exist? Can policy push the system past the tipping point?
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
Photon detectors based on micropattern gas detectors represent a new generation of gaseous photon detectors. In the context of a project to upgrade the gas photon detectors of COMPASS RICH-1, we are ...performing an R&D programme aimed both to establish the principles and to develop the engineering aspects of photon detectors based on multi-layer arrangements of thick GEMs electron multipliers coupled to a CsI photoconverter. In this context, a reduced rate of the backflow of the positive ions generated in the multiplication process is required to overcome the critical issues related to the bombardment of the CsI photoconverter by ions. Our studies devoted to develop detector architectures able to provide reduced ion backflow rates are reported.
This article describes the implementation of a mean-timer and coincidence logic on a Virtex-5 FPGA for trigger purposes in a particle physics experiment. The novel feature is that the mean-timing and ...the coincidence logic are not synchronized with a clock which allows for a higher resolution of approximately 400ps, not limited by a clock frequency.
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The photon detectors based on MPGD (MicroPattern Gaseous Detector) represent the new generation of gaseous photon detectors. We report about an R&D programme dedicated to study both the principles ...and the engineering aspects of photon detectors based on Thick GEMs (THGEM) electron multipliers coupled to a CsI photoconverting coating. The goal is the development of a gaseous detector of single UV photons, able to stably operate at high gain and high rate, to provide good time resolution and insensitive to magnetic field to be used in the Cherenkov imaging counter RICH-1 of the COMPASS experiment at CERN SPS.
With present-day detectors in high energy physics one often faces fast analog pulses of a few nanoseconds length which cover large dynamic ranges. In many experiments both amplitude and timing ...information have to be measured with high accuracy. Additionally, the data rate per readout channel can reach several MHz, which leads to high demands on the separation of pile-up pulses. For an upgrade of the COMPASS experiment at CERN we have designed the GANDALF transient recorder with a resolution of 12 bit@1 GS/s and an analog bandwidth of 500 MHz. Signals are digitized with high precision and processed by fast algorithms to extract pulse arrival times and amplitudes in real-time and to generate trigger signals for the experiment. With up to 16 analog channels, deep memories and a high data rate interface, this 6U-VME64x/VXS module is not only a dead-time free digitization unit but also has huge numerical capabilities provided by the implementation of a Virtex5-SXT FPGA. Fast algorithms implemented in the FPGA may be used to disentangle possible pile-up pulses and determine timing information from sampled pulse shapes with a time resolution better than 50 ps.
The GANDALF 6U-VME64x/VXS module has been developed for the digitization and real time analysis of detector signals. To perform different applications such as analog-to-digital or time-to-digital ...conversions, coincidence matrix formation, fast pattern recognition and trigger generation, this module comes with exchangeable analog and digital mezzanine cards. Based on this platform, we present a 128-channel TDC which is implemented in a single Xilinx Virtex-5 FPGA using a shifted clock sampling method. In contrast to common TDC concepts, the input signal is sampled by 16 equidistant phase-shifted clocks. A particular challenge of the design is the minimum skew routing of the input signals to the sampling flip-flops. We present measurement results for the differential nonlinearity and the time resolution of the TDC readout system.
The Longitudinal Polarimeter at HERA Beckmann, M; Borissov, A; Brauksiepe, S ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2002, Volume:
479, Issue:
2-3
Journal Article
Peer reviewed
Open access
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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