title: A method of obtaining the Awall correction factor of an ionization chamber in a 60Co gamma-ray beam using tissue-air ratio data.
abstract: A method is reported that evaluates the wall correction factor (Awall)water of an ionization chamber using measured data. The method needs a revised type of tissue-air ratio (TARcav) that should be measured with the ionization chamber. An experimental study has been carried out for 60Co gamma-rays using zero-area TARcav data extrapolated from non-zero-area TARcav data using the extrapolation method developed by Bjärngard and Petti. Using this technique, it is found that the value of (Awall)water for an ionization chamber has a deviation of -0.1% to -0.4% as compared with the Monte Carlo results. An experimental study has also been carried out using a published set of 60Co traditional tissue-air ratio (TAR) data assuming TARcav = TAR.
authors.affiliation: School of Allied Medical Sciences, Hirosaki University, Aomori, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Iwasaki
mesh_terms: D000388:Air; D055592:Biophysical Phenomena; D001703:Biophysics; D003037:Cobalt Radioisotopes; D004583:Electrons; D005720:Gamma Rays; D006801:Humans; D008961:Models, Structural; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000706:statistics & numerical data
chemical_list: D003037:Cobalt Radioisotopes