Premium
Determination of the solid angle of an Si(Li) detector
Author(s) -
Hopman Theodore L.,
Campbell John L.
Publication year - 2002
Publication title -
x‐ray spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.447
H-Index - 45
eISSN - 1097-4539
pISSN - 0049-8246
DOI - 10.1002/xrs.586
Subject(s) - collimator , solid angle , detector , position (finance) , optics , attenuation , cryostat , physics , radioactive source , computer science , superconductivity , finance , quantum mechanics , economics
Radial and longitudinal scanning of x‐ray detectors with a 55 Fe source is a widely used method for determining their dimensions and position within the cryostat and thence deducing solid angle in an analytical arrangement. The scanning method is refined here to take account of various effects and issues hitherto ignored and therefore reducing its accuracy; these include finite source size, collimator ‘channelling,’ and uncertainty as to the correction for x‐ray attenuation in the intervening air. With proper attention to these effects, it is possible to determine the window–crystal distance to an accuracy of about 0.2 mm; this translates into an accuracy of about 3% for solid angle when the source–detector distance is about 25 mm. However, uncertainty remains in calibrating an analytical system, owing to lack of knowledge of the actual construction of any internal collimator. Copyright © 2002 John Wiley & Sons, Ltd.