Standardization of Cesium - 137 Gamma - Ray Sources Terms of Exposure Units ( Roentgens ) . In
نویسنده
چکیده
'3'CS y~ray sources, whic h have been proposed by the Pub lic Health Service as a subs titute for radium in th e treatme nt of ma lignant diseases, require suitab le calibration if cons is tency is to be achie ved in radiation treatme nt. Several '"'Cs so urces we re ca libra ted using a graphite cavi ty ionizat ion chambe r in an open·ai r geometry. The co ntribution of scatter from the room surfaces was calculated and the so urce meas urements correc ted [or thi s effec t. A large-volume aluminum-walled ioni za tion chamber was des igned and fabricated [or use in routine ca libra tions. This chamber will be used as a means [or in te rcomparison of the source to be calibrated with one o[ the sta nd ards.
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