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Photoactivation ratios for specification of high‐energy x‐ray quality: Part II, 4–15‐MV x rays
Author(s) -
Schulz R. J.,
Nath Ravinder
Publication year - 1977
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.594300
Subject(s) - photodisintegration , neutron , foil method , indium , range (aeronautics) , deuterium , physics , x ray , materials science , neutron temperature , atomic physics , nuclear physics , analytical chemistry (journal) , radiochemistry , chemistry , optoelectronics , composite material , chromatography
A sensitive and relatively simple method for obtaining an index of the spectral quality of x rays in the 4–15‐MV range is presented. The method is based upon the simultaneous production of 115m In by inelastic scattering of x rays by an indium foil and the production of 116m In by neutron capture, where the neutrons are obtained from the photodisintegration of deuterium. Since the cross sections for the production of 115m In and 116m In have markedly different energy response functions, the ratio of radioactivities is very sensitive to the incident x‐ray spectrum. Using a detector consisting of an indium foil sandwiched between two plastic bottles of D 2 O, photoactivation ratios (PAR) have been measured for 4‐, 6‐, and 10‐MV x rays. It is shown that the PAR method offers a sensitive and practical means for quality control of x‐ray spectra and comparison of high‐energy accelerators.