Direct measurement of electron contamination in cobalt beams using a charge detector

Journal Article · Wed May 01 00:00:00 EDT 1985 · Med. Phys.; (United States)

DOI:https://doi.org/10.1118/1.595719· OSTI ID:5177917

Galbraith, D M; Rawlinson, J A

A method is described in some detail for measuring the magnitude and penetration of the electron contamination in photon beams using a pancake charge detector. It is shown that the response of the detector to a photon beam can be separated from the component due to the electron contamination. In the present work, the detector is used to measure the electron fluence in a /sup 60/Co photon beam. This fluence is subsequently converted to dose by comparison with the fluence and dose measured from a pure electron beam (/sup 90/Sr). This study proves, within experimental error, that the observed changes in the buildup region, with the collimator opening for both filtered and unfiltered /sup 60/Co beams, are due to electron, rather than photon, contamination.

• Research Organization: Ontario Cancer Institute, Toronto, Canada
• OSTI ID: 5177917
• Journal Information: Med. Phys.; (United States), Vol. 3
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ELECTRONS
FILTRATION
PHOTON BEAMS
IMPURITIES
COLLIMATORS
RADIATION DETECTORS
RADIATION DOSES
RADIOTHERAPY
STRONTIUM 90
ALKALINE EARTH ISOTOPES
BEAMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DOSES
ELEMENTARY PARTICLES
EVEN-EVEN NUCLEI
FERMIONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEPTONS
MEASURING INSTRUMENTS
MEDICINE
NUCLEAR MEDICINE
NUCLEI
RADIOISOTOPES
RADIOLOGY
SEPARATION PROCESSES
STRONTIUM ISOTOPES
THERAPY
YEARS LIVING RADIOISOTOPES
550603* - Medicine- External Radiation in Therapy- (1980-)
440100 - Radiation Instrumentation