Status of triple GEM muon chambers for the LHCb experiment Alfonsi, M.; Bencivenni, G.; Bonivento, W. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2007, Letnik:
581, Številka:
1
Journal Article
Recenzirano
Muon triggering and offline muon identification are fundamental requirements for the LHCb experiment, which will begin to take data at the start-up of the LHC machine. The identification of muon ...particles and an estimate of the transverse momentum (
Δ
p
T
/
p
T
∼
20
%
) in the near-beam area of the first muon station is achieved by a set of 12 double triple-GEM detectors which covers an area of about
0.6
m
2
. Since b-quark production is peaked in the forward direction, GEM detectors will trigger about 20% of muons from B-particle decays. In this paper the results of the detector quality checks on anode and cathode panels planarity, GEM foil HV test, chamber gas leak and gain uniformity are presented. The performance of a chamber, composed of two triple-GEM detectors logically OR-ed, has been measured in a recent test beam at the SPS, with particle bunches with a time structure of 25
ns similar to the LHC running conditions. In this test the final front-end electronics and the final LHCb DAQ have been used. This result demonstrates that the detector can achieve the required performances (efficiency larger than 96%) at a detector gain of 4000, thus ensuring a long detector lifetime in the harsh LHCb environment.
The IDEA detector concept has been designed to operate at a future large circular e+e− collider, like FCC-ee or CEPC. The IDEA detector has an innovative design with a central tracker enclosed in a ...superconducting solenoidal magnet. Going outwards, a preshower system followed by a dual readout calorimeter is foreseen. In the iron yoke, that closes the magnetic field, are then located three stations of muon detectors. The preshower and muon detectors are based on the μ-RWELL technology that inherits the best characteristics of the GEM, in particular the layout of the amplification stage, and Micromega detectors, that inspired the presence of a resistive stage. To profit of the industrial production capabilities of this technology, a modular design has been adopted for both systems: the μ-RWELL tile will have an active area of 50 × 50 cm2, but with a pitch between the readout strips of 400μm for the preshower and about 1 mm for the muon system. Other requirements are: a spatial resolution of the order of 100μm for the preshower and a reasonable total number of front-end channels for the muon system. To optimize the resistivity and the strip pitch, we have built a set of prototypes with active area of 5 × 40 cm2 and 40 cm long strips. The DLC resistivity is ranging from 10 to 80 MΩ/□. All these detectors have been exposed in October 2021 to a muon beam at the CERN SPS. The very positive results obtained pave the way for a completely new and competitive MPGD tracking device for high energy physics experiments.
The AMADEUS experiment deals with the investigation of the low-energy kaon-nuclei hadronic interaction at the DAΦNE collider at LNF-INFN, fundamental to respond to longstanding open questions in the ...non-perturbative QCD in the strangeness sector. One of the most interesting aspects is to understand how hadron masses and interactions change in the nuclear environment. The antikaon-nucleon potential is investigated searching for signals from possible bound kaonic clusters, which would imply a strongly attractive antikaon-nucleon potential. AMADEUS step 0 consists in the analysis of 2004/2005 KLOE data, exploring K− absorptions in H, 4He, 9Be and 12C present in setup materials. The status of the various preliminary analyses is presented, together with future perspectives.
A triple-gas electron multiplier (GEM) detector, operated with the gas mixture Ar/CO 2 /CF 4 (45/15/40), is going to equip station M1, region R1 of the LHCb muon system. A Module-0 of this detector, ...with full area (20 cmtimes24 cm) GEM foils, was recently built and tested. In this paper, new measurements of efficiency and pad multiplicity are presented. These new measurements were very important to select of the final pad board configuration. The sensitivity to discharges is a very important issue in this type of detector; we discuss here new measurements of the maximum number of discharges that a triple-GEM detector can stand before breakdown, and we show that detector operation in LHCb is safe from this point of view. We also discuss new measurements of the time performance of the detector in the presence of background radiation, indicating that no significant deterioration of the performances is expected in the LHCb environment
The AMADEUS experiment has the aim to perform studies of the low energy hadronic interactions of negatively charged kaons with nucleons and nuclei, which are fundamental to solve longstanding open ...questions in the non-perturbative QCD in the strangeness sector. The DAphiNE collider provides a unique source of monochromatic low-momentum kaons, whose nuclear interaction with the materials of the KLOE detector (used as an active target) provide us excellent acceptance and resolution data for K super(-) capture on H, super(4)He, super(9)Be and super(12)C, both at-rest and in-flight. AMADEUS step 0 consisted in the analysis of the 2004-2005 KLOE data. A second step consisted in the implementation in the central region of the KLOE detector of a pure graphite target, providing a high statistic sample of K super(-) super(12)C nuclear captures at rest. For the future, new setups for various dedicated targets are under preparation. The aim of such investigations is to face the major open questions in hadron nuclear physics in the strangeness sector, such as the nature of the E(1405) state and the resonant versus non-resonant yield in nuclear K super(-) capture, the possible existence of kaonic nuclear clusters, strongly related to a quantitative understanding of single versus multi-nucleon K super(-) absorption.
The DAΦNE electron-positron collider at the Laboratori Nazionali di Frascati of INFN, Italy has made available a unique quality low-energy negatively charged kaons “beam”, which is used to unveil the ...secrets of the kaon-nucleon/nuclei interactions at low energies by the SIDDHARTA-2 and AMADEUS experiments. SIDDHARTA has already performed unprecedented precision measurements of kaonic atoms, and is being presently upgraded, as SIDDHARTA-2, to approach new frontiers. The AMADEUS experiment plans to perform in the coming years precision measurements on kaon-nuclei interactions at low-energies, to study the possible formation of kaonic nuclei, of the Λ(1405) and of many other processes involving strangeness.
The AMADEUS experiment aims to perform dedicated precision studies in the sector of low-energy kaon-nuclei interaction at the DAΦNE collider at LNF-INFN. In particular, the experiment plans to ...perform measurements of the debated deeply bound kaonic nuclear states, to deepen our knowledge about the controversial state Λ(1405) and to measure the low energy cross section of K− on light nuclei. AMADEUS will exploit the process of stopped kaons in cryogenic gaseous targets, measuring both charged and neutral particles produced in a 4π geometry, so performing a full study of the various interaction channels. Taking advantage of the fact that the KLOE drift chamber is mainly filled with 4He (90% helium 10% isobutane) according to Monte Carlo simulations about 0.1% of kaons from DAΦNE should stop in the inner volume of the drift chamber; the analysis of the existing KLOE data (run from 2002 to 2005) is presently going on, searching for hadronic interactions of K− in such an active target. The AMADEUS physics program and preliminary results from the analysis of KLOE data will be discussed.
The
system at rest plays a key role for the understanding of strong interaction of hadrons with strangeness involved. The experiment SIDDHARTA used X-ray spectroscopy of kaonic atoms to measure the ...strong interaction induced shift and width of the ground state. It was the first experiment on kaonic He3 and deuterium ever, kaonic hydrogen was measured with improved precision resulting in
eV and
eV. Additionally a scheme for an improved future experiment on kaonic deuterium is introduced in this contribution.
In this paper, we summarize the results obtained in an R&D work performed in the period 2000-2003 within the LHCb Collaboration to develop a triple gas electron multiplier (GEM) for the inner region ...of the first muon station. Since the information coming from this detector will be used at the L0 trigger level, many studies were performed in order to optimize its time resolution. By using CF/sub 4/-based gas mixtures, a time resolution of 4.5 ns rms was obtained, which translates to efficiencies higher than 96% in a 20-ns time window for a large operating region. Moreover, measurements of discharge probability per incident charged particle with a high-intensity pion/proton beam for these gas mixture are also reported. All these results show that triple-GEM detectors can be used for triggering in the LHCb muon detector. Preliminary results on a global aging test performed with a 25-kCi /sup 60/Co source are also reported and compared to other aging tests performed with X-rays and hadron beams.
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