Large-window gas proportional scintillation counter with photosensor compensation
- Univ. de Coimbra (Portugal). Dept. de Fisica
New methods are presented that allow the design the 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 windows 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 photomultipler 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.
- OSTI ID:
- 129151
- Report Number(s):
- CONF-941061--
- Journal Information:
- IEEE Transactions on Nuclear Science, Journal Name: IEEE Transactions on Nuclear Science Journal Issue: 4Pt1 Vol. 42; ISSN 0018-9499; ISSN IETNAE
- Country of Publication:
- United States
- Language:
- English
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