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Improved “nonisolated‐sensor” solid polystyrene calorimeter
Author(s) -
Zeitz Louis,
Ulin Kenneth,
Caley Richard
Publication year - 1986
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 - 10.1118/1.595883
Subject(s) - polystyrene , calorimeter (particle physics) , materials science , radiochemistry , nuclear medicine , medical physics , physics , optics , nuclear magnetic resonance , medicine , chemistry , detector , polymer
A “nonisolated‐sensor” solid polystyrene calorimeter is described which permits absorbed dose measurements with precision of less than 0.3% (standard error of the mean). The accuracy for obtaining absolute absorbed dose was estimated by comparisons with cavity ionization measurements. The calculation of absorbed dose with ionization chambers was carried out based upon the TG‐21 AAPM dosimetry protocol. Measurements in a 6 0 Co γ‐ray field with three different polystyrene parallel‐plate ion chambers in a polystyrene phantom did not differ by more than 1.5% from that obtained with the polystyrene calorimeter. Measurements taken over a period of 247 days are compared with the expected values on the basis of the decay of 6 0 Co. The calorimeter system, with its capability of acquiring, printing, storing, plotting, and analyzing the data by computer, is described.