1981 年 1 巻 1 号 p. 31-40
Reciprocal visits have been made to National Institute of Radiological Sciences by the physicists from Texas A&M University, M. D. Anderson Hospital, University of Washington and Institute of Medical Sciences of Tokyo Univertity for a neutron dosimetry Intercomparison in 1976. The parameters that the usually measured are tissue dose in air, tissue dose at the depths of 5,10,15 and 20 cm in TE liquid phantom, neutron/gamma ratios in air and in phantom, and photon calibration of ionization chambers. Other parameters that are compared are kT-factor and ku-factor which are concerned in W-value, stopping power ratios and kerma ratios, and correction factor for an ion loss by recombination. After the intercomparison the measurements of ku have been made by NIRS physicists using the modified lead filtration method. The reevaluation of the data has been made for a comparison using an observed ku and theoretical kT which has been calculated using revised kerma factors by ICRU in 1977. This paper describes some of the results of the intercomparison and discusses the implications of the findings.
