Open AccessMeasurements of spatial variations in response of ionization chambers
Author(s) -
Miller William E. B.,
Kastengren Alan L.
Publication year - 2013
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049512041337
Subject(s) - saturation (graph theory) , ionization chamber , ionization , saturation current , spatial variability , space charge , atomic physics , materials science , analytical chemistry (journal) , voltage , optics , physics , chemistry , nuclear physics , ion , environmental chemistry , statistics , mathematics , combinatorics , quantum mechanics , electron
Measurements of the spatial variations in the response of three ionization chamber (IC) designs were tested as a function of chamber bias voltage, incident X‐ray flux and fill gas. Two components of spatial variation are seen. When the ionization chambers are near saturation, spatial variations exist that are tied to the chamber geometry. While the response of some chambers is relatively flat, others show significant variation across the IC. These variations appear to be inherent in the response of each IC at saturation. When the chamber is far from saturation, large spatial variations in response are present when N 2 is used as a fill gas, but not when ambient air is used as a fill gas. These appear to be tied to space charge effects.