123 research outputs found
On the localization properties of an RPWELL gas-avalanche detector
A study of the localization properties of a single-element Resistive Plate
WELL (RPWELL) detector is presented. The detector comprises of a single-sided
THick Gaseous Electron Multiplier (THGEM) coupled to a segmented readout anode
through a doped silicate-glass plate of 10 cm bulk
resistivity. Operated in ambient Ne/(5CH) gas, the detector has been
investigated with 150 GeV muons at CERN-SPS. Signals induced through the
resistive plate on anode readout strips were recorded with APV25/SRS
electronics. The experimental results are compared with that of Monte Carlo
simulations. The effects of various physics phenomena on the position
resolution are discussed. The measured position resolution in the present
configuration is 0.28 mm RMS - compatible with the holes-pattern of the
multiplier. Possible ways for improving the detector position resolution are
suggested
Time-resolved fast-neutron imaging with a pulse-counting image intensifier
A new imaging method that combines high-efficiency fast-neutron detection with sub-ns time resolution is presented. This is achieved by exploiting the high neutron detection efficiency of a thick scintillator and the fast timing capability and flexibility of light-pulse detection with a dedicated image intensifier. The neutron converter is a plastic scintillator slab or, alternatively, a scintillating fibre screen. The scintillator is optically coupled to a pulse counting image intensifier which measures the 2-dimensional position coordinates and the Time-Of-Flight (TOF) of each detected neutron with an intrinsic time resolution of less than 1 ns. Large-area imaging devices with high count rate capability can be obtained by lateral segmentation of the optical readout channels
Photocathodes for a post-processed imaging array
Preliminary results of a photon detector combining a Micromegas like multiplier coated with a UV-sensitive CsI photocathode are described. The multiplier is made in the CMOS compatible InGrid technology, which allows to post-process it directly on the surface of an imaging IC. This method is aimed at building light-sensitive imaging detectors where all elements are monolithically integrated. We show that the CsI photocathode deposited in the InGrid mesh does not alter the device performance. Maximum gains of ~6000 were reached in a singlegrid element operated in Ar/CH4, with a 2% Ion Back Flow fraction returning to the photocathode
A UV Sensitive Integrated Micromegas with Timepix Readout
This article presents a detector system consisting of three components, a
CMOS imaging array, a gaseous-detector structure with a Micromegas layout and a
UV-photon sensitive CsI reflective photocathode. All three elements have been
monolithically integrated using simple post-processing steps. The Micromegas
structure and the CMOS imaging chip are not impacted by the CsI deposition. The
detector operated reliably in He/isobutane mixtures and attained charge gains
with single photons up to a level of 6 \cdot 10^4. The Timepix CMOS array
permitted high resolution imaging of single UV-photons. The system has an MTF50
of 0.4 lp/pixel which corresponds to app. 7 lp/mm.Comment: 4 pages with 8 figures. Submitted to Nucl. Instr. and Meth. A
(Elsevier) for proceedings of VCI 2010
Progress with Xenon Liquid Hole Multipliers
The bubble-assisted Liquid Hole Multiplier (LHM) is a recently-proposed
concept for the combined detection of ionization electrons and primary
scintillation photons in noble-liquid time projection chambers. The LHM
comprises a perforated micro-pattern electrode (e.g. Thick Gas Electron
Multiplier - THGEM, or Gas Electron Multiplier - GEM) immersed in the liquid,
with a bubble of the noble gas supported underneath. Ionization electrons and
scintillation-induced photoelectrons extracted from a cesium iodide
photocathode drift through the electrode's holes and induce electroluminescence
(EL) signals in the bubble; these are recorded by photon detectors located
closely below the electrode. We present recent results in the development of
LHMs, comparing the response of different electrodes to ionization and
photon-induced electrons.Comment: Presented at 2016 IEEE NSS/MIC, Strasbourg, France, 29 October - 5
November 201
An integrated Micromegas UV-photon detector
Preliminary results of a photon detector combining a Micromegas like
multiplier coated with a UV-sensitive CsI photocathode are described. The
multiplier is made in a CMOS compatible InGrid technology, which allows to
post-process it directly on the surface of an imaging IC. This method is aimed
at building light-sensitive imaging detectors where all elements are
monolithically integrated. We show that the CsI photocathode deposited in the
InGrid mesh does not alter the device performance. Maximum gains of ~6000 were
reached in a single-grid element operated in Ar/CH4, with a 2% Ion Back Flow
fraction returning to the photocathode.Comment: 5 pages with 6 figures. This paper is submitted to Nuclear
Instruments and Methods A (Elsevier) for the proceedings of IWORID 2009
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