DocumentCode :
994134
Title :
Large-window gas proportional scintillation counter with photosensor compensation
Author :
Veloso, J.F.C.A. ; dos Santos, J.M.F. ; Conde, C.A.N.
Author_Institution :
Dept. de Fisica, Coimbra Univ., Portugal
Volume :
42
Issue :
4
fYear :
1995
fDate :
8/1/1995 12:00:00 AM
Firstpage :
369
Lastpage :
373
Abstract :
New methods are presented that allow the design of non-focused gas proportional scintillation counters (GPSC) with window areas that approximate the photomultiplier window area. These methods are alternatives to a previously reported technique that uses a non-uniform electric field produced by a curved grid to compensate for the radial decrease of the scintillation light collected in the photosensor due to solid angle and reflection effects. The present work reverts to a uniform electric field and compensation is achieved with a mask with a radially-decreasing density of opaque dots that are deposited onto the window of the photosensor. The variation in the density of opaque dots is calculated to produce radially-independent light collection in the photosensor. An implementation of this new design is presented for a 52-mm-diameter photomultiplier tube with a 46-mm-effective diameter. The variation in pulse amplitude as a function of radial position was observed to be reduced from 18% to only 3.5% over the area contained within the central 19 mm radius. For a 38-mm-diameter window, the energy resolution for 5.9 keV X-rays was improved from 18% to 10% with the addition of the compensating mask
Keywords :
X-ray detection; gas scintillation detectors; photomultipliers; proportional counters; 38 mm; 46 mm; 5.9 keV; 52 mm; X-rays; compensating mask; energy resolution; large-window gas proportional scintillation counter; nonfocused gas proportional scintillation counters; opaque dots; photomultiplier tube; photomultiplier window area; photosensor compensation; pulse amplitude variation; radially-decreasing density; radially-independent light collection; uniform electric field; Chromium; Electrons; Energy resolution; Optical reflection; Photomultipliers; Scintillation counters; Solid scintillation detectors; Testing; X-rays; Xenon;
fLanguage :
English
Journal_Title :
Nuclear Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9499
Type :
jour
DOI :
10.1109/23.467818
Filename :
467818
Link To Document :
بازگشت