Several small single gap Resistive Plate Chambers and two RB1 CMS final stations have been exposed during the last year at the CERN Gamma Irradiation Facility to study possible long-term ageing ...effects. Up to now, an integrated charge of about 0.05C/(cm2gap) and 0.025 C/(cm2 gap) has been accumulated for the small RPCs and the large RB1 stations, respectively. Current, rate, fast charge and efficiency have been continuously monitored with muon beam or cosmics. Results concerning operation with a moisty mixture are also reported.
In the CERN CMS experiment at LHC Collider special trigger signals called
Technical Triggers will be used for the purpose of test and calibration. The Resistive Plate Chambers (RPC) based Technical ...Trigger system is a part of the CMS muon trigger system and is designed to detect cosmic muon tracks. It is based on two boards, namely RBC (RPC Balcony Collector) and TTU (Technical Trigger Unit). The proposed tracking algorithm (TA) written in VHDL and implemented in the TTU board detects single or multiple cosmic muon tracks at every bunch crossing along with their track lengths and corresponding chamber coordinates. The TA implementation in VHDL and its preliminary simulation results are presented.
Study of gas purifiers for the CMS RPC detector Benussi, L.; Bianco, S.; Colafranceschi, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2012, Volume:
661
Journal Article
Peer reviewed
Open access
The CMS RPC muon detector utilizes a gas recirculation system called closed loop (CL) to cope with large gas mixture volumes and costs. A systematic study of CL gas purifiers has been carried out ...over 400 days between July 2008 and August 2009 at CERN in a low-radiation test area, with the use of RPC chambers with currents monitoring, and gas analysis sampling points. The study aimed to fully clarify the presence of pollutants, the chemistry of purifiers used in the CL, and the regeneration procedure. Preliminary results on contaminants release and purifier characterization are reported.
We describe a pilot project (GAP – GPU Application Project) for the use of GPUs (Graphics processing units) for online triggering applications in High Energy Physics experiments. Two major trends can ...be identified in the development of trigger and DAQ systems for particle physics experiments: the massive use of general-purpose commodity systems such as commercial multicore PC farms for data acquisition, and the reduction of trigger levels implemented in hardware, towards a fully software data selection system ("trigger-less"). The innovative approach presented here aims at exploiting the parallel computing power of commercial GPUs to perform fast computations in software not only in high level trigger levels but also in early trigger stages. General-purpose computing on GPUs is emerging as a new paradigm in several fields of science, although so far applications have been tailored to the specific strengths of such devices as accelerators in offline computation. With the steady reduction of GPU latencies, and the increase in link and memory throughputs, the use of such devices for real-time applications in high energy physics data acquisition and trigger systems is becoming relevant. We discuss in detail the use of online parallel computing on GPUs for synchronous low-level triggers with fixed latency. In particular we show preliminary results on a first test in the CERN NA62 experiment. The use of GPUs in high level triggers is also considered, the CERN ATLAS experiment being taken as a case study of possible applications.
The APEnet+ board delivers a point-to-point, low-latency, 3D torus network interface card. In this paper we describe the latest generation of APEnet NIC, APEnet v5, integrated in a PCIe Gen3 board ...based on a state-of-the-art, 28 nm Altera Stratix V FPGA. The NIC features a network architecture designed following the Remote DMA paradigm and tailored to tightly bind the computing power of modern GPUs to the communication fabric. For the APEnet v5 board we show characterizing figures as achieved bandwidth and BER obtained by exploiting new high performance ALTERA transceivers and PCIe Gen3 compliancy.
ExaNest is one of three European projects that support a ground-breaking computing architecture for exascale-class systems built upon power-efficient 64-bit ARM processors. This group of projects ...share an "everything-close" and "share-anything" paradigm, which trims down the power consumption - by shortening the distance of signals for most data transfers - as well as the cost and footprint area of the installation - by reducing the number of devices needed to meet performance targets. In ExaNeSt, we will design and implement: (i) a physical rack prototype and its liquid-cooling subsystem providing ultra-dense compute packaging, (ii) a storage architecture with distributed (in-node) non-volatile memory (NVM) devices, (iii) a unified, low-latency interconnect, designed to efficiently uphold desired Quality-of-Service guarantees for a mix of storage with inter-processor flows, and (iv) efficient rack-level memory sharing, where each page is cacheable at only a single node. Our target is to test alternative storage and interconnect options on actual hardware, using real-world HPC applications. The ExaNeSt consortium brings together technology, skills, and knowledge across the entire value chain, from computing IP, packaging, and system deployment, all the way up to operating systems, storage, HPC, big data frameworks, and cutting-edge applications.
Resistive plate chamber commissioning and performance in CMS Roselli, G.; Abbrescia, M.; Iaselli, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2009, Volume:
602, Issue:
3
Journal Article
Peer reviewed
The CMS muon system is conceived for trigger and muon track reconstruction. The redundancy and robustness of the system are guaranteed by three complementary subsystems: drift tube in the barrel, ...cathode strip chamber in the end-cap and resistive plate chamber in barrel and end-cap. The installation of muon stations and read-out trigger electronic has been completed in middle 2007. Since than, a remarkable effort has been addressed to the detector commissioning in order to ensure the readiness of the hardware/software chain for the LHC start up operation. At the end of 2007, a test of an entire CMS slice has been performed, involving about 5% of muon stations. Several thousand cosmic muons events have been collected. Performance of the barrel chambers are reported.
The status of the Compact Solenoid Spectrometer (CMS) Resistive Plate Counter (RPC) Gas Gain Monitoring (GGM) system developed at the Frascati Laboratory of INFN (Istituto Nazionale di Fisica ...Nucleare) is reported. The GGM system is a cosmic ray telescope based on small RPC detectors operated with the same gas mixture used by the CMS RPC system. The GGM gain and efficiency are continuously monitored on-line, thus providing a fast and accurate determination of any shift in working point conditions. The construction details and the first result of GGM commissioning are described.
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