The surface Resistive Plate Counter (sRPC) is a new RPC based on surface resistive electrodes realized with Diamond-Like-Carbon (DLC) sputtered on Apical\protect \relax \special {t4ht=®} foil. ...Exploiting the high rate resistive MPGD technology, detectors able to stand several tens of kHz/cm2 can be easily developed. The scalability of the technology allows the construction of detectors for large area applications at future high luminosity colliders.
Triple-GEM detectors with pad readout have been employed to equip the innermost region (R1) of the first station (M1) within the Muon system of the LHCb experiment. The GEM detectors have been ...operated with an Ar/CO2/CF4 = 45/15/40 gas mixture at a gas gain of about 4000 with an average particle flux of about 250 kHz/cm2. Throughout RUN1 and RUN2, spanning approximately 440 days of colliding beams, the GEM detectors accumulated a charge of up to 0.5 C/cm2. This paper presents a comparative analysis between a global irradiation test of GEM detectors at the Calliope facility (ENEA-Casaccia, 1.25 MeV γ ray flux from a 60Co source) and the GEMs operated at LHCb, focusing on the impacts of a CF4-based gas mixture. In both instances, the detectors were opened and the GEM foils were examined by the EN-MME-MM CERN group with a Field Emission Gun Scanning Electron Microscope (FEG-SEM) for a magnified image analysis and an X-Max Energy Dispersive X-ray Spectroscopy (EDS) for the chemical one.
Performance of μ-RWELL detector vs resistivity of the resistive stage Bencivenni, G.; De Oliveira, R.; Felici, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2018, Letnik:
886
Journal Article
Recenzirano
Odprti dostop
The μ-RWELL is a compact spark-protected single amplification stage Micro-Pattern-Gaseous-Detector (MPGD). The detector amplification stage is realized with a polyimide structure, micro-patterned ...with a dense matrix of blind-holes, integrated into the readout structure. The anode is formed by a thin Diamond Like Carbon (DLC) resistive layer separated by an insulating glue layer from the readout strips. The introduction of the resistive layer strongly suppressing the transition from streamer to spark gives the possibility to achieve large gains (> 104), without significantly affecting the capability to be efficiently operated in high particle fluxes. In this work we present the results of a systematic study of the μ-RWELL performance as a function of the DLC resistivity. The tests have been performed either with collimated 5.9 keV X-rays or with pion and muon beams at the SPS Secondary Beamline H4 and H8 at CERN.
The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the ...light vector mediator of this dark force, the U boson, with the KLOE detector at the DAΦNE e+e− collider. Using an integrated luminosity of 1.54 fb−1, we studied the process e+e−→Uγ, with U→e+e−, using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ε2, at 10−6–10−4 in the 5–520 MeV/c2 mass range.
High space resolution μ-RWELL for high particle rate Bencivenni, G.; De Oliveira, R.; Felici, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
The μ-RWELL is a single-amplification stage resistive MPGD. The amplification element, realized on a polyimide foil micro-patterned with a high density blind-holes (wells), is embedded through a thin ...resistive film, in the readout PCB. The introduction of the resistive layer affects the charge spread on the readout electrodes and suppresses the transition from streamer to spark giving the possibility to achieve large gains (>104). As a drawback the capability to stand high particle fluxes is reduced. In order to get rid of such a limitation different resistive layouts with prompt current evacuation schemes have been designed. In this work we present the study of the performance of the high rate layouts done at PSI, together with the measurement of the space resolution for orthogonal and inclined tracks performed at CERN.
We have searched for a light vector boson U, the possible carrier of a “dark force”, with the KLOE detector at the DAΦNE e+e− collider, motivated by astrophysical evidence for the presence of dark ...matter in the Universe. Using e+e− collisions collected with an integrated luminosity of 239.3 pb−1, we look for a dimuon mass peak in the reaction e+e−→μ+μ−γ, corresponding to the decay U→μ+μ−. We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the mixing parameter squared between the photon and the U boson of 1.6×10−5 to 8.6×10−7 for the mass region 520<mU<980 MeV.
The μ-RWELL is a new generation Micro-Pattern Gaseous Detector, composed of two elements: the cathode and the μ-RWELL_PCB including the amplification stage, realized with a polyimide structure ...micro-patterned with a blind-hole matrix, embedded through a Diamond-Like Carbon (DLC) resistive layer with the readout PCB. Different layouts of the resistive stage have been studied: the simplest one is based on a single DLC layer with edge grounding, suitable for low rate applications (30–40 kHz/cm2). More sophisticated schemes are under study for high-rate purposes (up to 2–3 MHz/cm2) in order to optimize the performance and the constructive process. For the phase-2 upgrade of the LHCb muon detector the experiment is targeting a luminosity of 2×1034 cm−2 s−1, with strong requirements on the robustness and detection efficiency of the muon system. We report on the ongoing R&D, showing also the latest measured performances of the new high-rate versions of the detector.
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