Accession Number : AD0451608


Title :   FRACTIONAL EXPOSURE RATE DUE TO SCATTERED RADIATION FROM A CO60 TELETHERAPY UNIT,


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


Personal Author(s) : Henry,W H ; Garrett,C


Report Date : 18 Dec 1963


Pagination or Media Count : 1


Abstract : The useful radiation beam from a Co60 teletherapy unit consists of not only primary photons of 1.17 and 1.33 MeV but also photons of lower energies resulting from scattering both within the source itself and by the material of the teletherapy head. A small number of fluorescent photons arising from photoelectric events also would be present in the beam, but these can be considered here to be included with the scattered photons. The relative magnitude of the contribution of scattered photons to the total exposure rate, in roentgens per unit time, can be important for some purposes. This report describes a measurement which has been made of the fractional exposure rate due to photons scattered by the material of the teletherapy head but excluding photons scattered within the source itself. (Author)


Descriptors :   *RADIATION DOSAGE , *PHOTONS , MEASUREMENT , SCATTERING , DOSE RATE , EXPOSURE(PHYSIOLOGY) , RADIOTHERAPY , IONIZATION CHAMBERS , COLLIMATORS , BEAMS(ELECTROMAGNETIC) , RADIOACTIVE ISOTOPES , COBALT


Distribution Statement : APPROVED FOR PUBLIC RELEASE