Accession Number : AD0611645

Title :   SPECTRA OF THE INTERNALLY SCATTERED RADIATION FROM LARGE CO 60 SOURCES USED IN TELETHERAPY,

Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO) DIV OF APPLIED PHYSICS

Personal Author(s) : Aitken,J. H. ; Henry,W. H.

Report Date : 09 JAN 1964

Pagination or Media Count : 13

Abstract : Because of internal scattering and degradation of the 1.33 and 1.17 MeV quanta, the beam of radiation from a Co60 teletherapy unit includes a continuous spectrum extending well below 1 MeV. The form of this spectrum below l MeV and its intensity relative to the radiation above 1 MeV have been investigated for sources of various dimensions. The influence of the material around the source, the relative spectral contributions of different parts of the source, and the spectra from bare sources outside the teletherapy head have also been studied. Methods of designing source and head to minimize the radiation below 1 MeV may be inferred from the graphs. (Author)

Descriptors :   (*RADIOTHERAPY, COBALT), (*GAMMA RAY SCATTERING, GAMMA RAY SPECTRA), (*GAMMA RAY SPECTRA, COBALT), CONTINUOUS SPECTRA, LINE SPECTRA, SHIELDING, NUCLEAR RADIATION SPECTROMETERS, RADIOACTIVE ISOTOPES

Distribution Statement : APPROVED FOR PUBLIC RELEASE