250 research outputs found
Study of MicroPattern Gaseous detectors with novel nanodiamond based photocathodes for single photon detection in EIC RICH
Identification of high momentum hadrons at the future EIC is crucial, gaseous
RICH detectors are therefore viable option. Compact collider setups impose to
construct RICHes with small radiator length, hence significantly limiting the
number of detected photons. More photons can be detected in the far UV region,
using a windowless RICH approach. QE of CsI degrades under strong irradiation
and air contamination. Nanodiamond based photocathodes (PCs) are being
developed as an alternative to CsI. Recent development of layers of
hydrogenated nanodiamond powders as an alternative photosensitive material and
their performance, when coupled to the THick Gaseous Electron Multipliers
(THGEM)-based detectors, are the objects of an ongoing R\&D. We report about
the initial phase of our studies.Comment: 3 pages, 5 figures, RICH2018 conference proceedin
The high voltage system for the novel MPGD-based photon detectors of COMPASS RICH-1
The architecture of the novel MPGD-based photon detectors of COMPASS RICH-1
consists in a large-size hybrid MPGD multilayer layout combining two layers of
Thick-GEMs and a bulk resistive MICROMEGAS. Concerning biasing voltage, the
Thick-GEMs are segmented in order to reduce the energy released in case of
occasional discharges, while the MICROMEGAS anode is segmented in pads
individually biased at positive voltage, while the micromesh is grounded. In
total, there are ten different electrode types and more than 20000 electrodes
supplied by more than 100 HV channels. Commercial power supply units are used.
The original elements of the power supply system are the architecture of the
voltage distribution net, the compensation, by voltage adjustment, of the
effects of pressure and temperature variation affecting the detector gain and a
sophisticated control software, which allows to protect the detectors against
errors by the operator, to monitor and log voltages and current at 1 Hz rate
and to automatically react to detector misbehaviors. The HV system and its
performance are described in detail as well as the electrical stability of the
detector during the operation at COMPASS.Comment: 5th international conference on Micro-Pattern Gas Detectors
(MPGD2017),presentation by Silvia Dalla Torr
Nanodiamond photocathodes for MPGD-based single photon detectors at future EIC
The design of a Ring Imaging CHerenkov (RICH) detector for the identification
of high momentum particles at the future Electron Ion Collider (EIC) is
extremely challenging by using current technology. Compact collider setups
impose to construct RICH with short radiator length, hence limiting the number
of generated photons. The number of detected photons can be increased by
selecting the far UV region. As standard fused-silica windows is opaque below
165 nm, a windowless RICH can be a possible approach. CsI is widely used
photocathode (PC) for photon detection in the far UV range. Due to its
hygroscopic nature it is very delicate to handle. In addition, its Quantum
Efficiency (QE) degrades in high intensity ion fluxes. These are the key
reasons to quest for novel PC with sensitivity in the far UV region. Recent
development of layers of hydrogenated nanodiamond powders as an alternative PC
material and their performance, when coupled to the THick Gaseous Electron
Multipliers (THGEM)-based detectors, are the objects of an ongoing R\&D. We
report here some preliminary results on the initial phase of these studies.Comment: 6 pages, 5 figures, MPGD-2019 La Rochelle, Proceedin
Nanodiamond photocathodes for MPGD-based single photon detectors at future EIC
We are developing gaseous photon detectors for Cherenkov imaging applications
in the experiments at the future Electron Ion Collider. CsI, converting photons
in the far ultraviolet range, is, so far, the only photoconverter compatible
with the operation of gaseous detectors. It is very delicate to handle due to
its hygroscopic nature: the absorbed water vapour decomposes the CsI molecule.
In addition, its quantum efficiency degrades under ion bombardment. These are
the key reasons to quest for novel, less delicate materials for photocathodes
adequate for gaseous photon detectors. Layers of hydrogenated nanodiamond
particles have recently been proposed as an alternative material and have shown
promising characteristics. The performance of nanodiamond photocathodes coupled
to thick GEM-based detectors is the object of our ongoing R\&D. The first phase
of these studies includes the characterization of thick GEM coated with
nanodiamond layers and the robustness of its photoconverting properties with
respect to the bombardment by ions from the multiplication process in the
gaseous detector. The approach is described in detail as well as all the
results obtained so far within these exploratory studies
A scalable High Voltage Power Supply System with system on chip control for Micro Pattern Gaseous Detectors
The requirements posed to high voltage power supply systems by the operation of Micro Pattern Gaseous Detectors are specific in terms of high resolution diagnostic features and intelligent dynamic voltage control. These requirements are needed both when technology development is performed and when extended detector systems are supplied and monitored. Systems satisfying all the needed features are not commercially available.
A single channel high voltage system matching the Micro Pattern Gaseous Detector needs has been designed and realized, including its hardware and software components. The system employs a commercial DCDC converter and is coupled to a custom high resolution ammeter. Local intelligence, flexibility and high speed inter-connectivity are provided by a System on Chip Board and the use of a powerful FPGA. The single channel system has been developed, as critical milestone towards the realization of a multi-channel system.
The design, implementation and performance of the system are reported in detail in this article, as well as the performance of the single channel power supply when connected to a Micro Pattern Gaseous Detector in realistic working condition during a test beam exercise
Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target
Multiplicities of charged pions and unidentified hadrons produced in
deep-inelastic scattering were measured in bins of the Bjorken scaling variable
, the relative virtual-photon energy and the relative hadron energy .
Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and
an isoscalar target (LiD). They cover the kinematic domain in the photon
virtuality > 1(GeV/c, , and . In addition, a leading-order pQCD analysis was performed using the
pion multiplicity results to extract quark fragmentation functions
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