Microdosimetric characteristics of radiation in IBR-30 and WWR-SM reactor channels

Calculations were made of microdosimetric parameters of radiation in the channels of reactors IBR-30 in Dubna and WWR-SM in Budapest which are often used for radiobiology experiments, this for a spherical microvolume of tissue-equivalent material of 1 μm in diameter. A simple method of determining linear energy spectra of neutron fission sources was developed. The method was tested in the radiation field of a known 252Cf source. It was shown that the quality of reactor beam radiation depends on the proportion of gamma and neutron doses rather than on the neutron energy spectrum shape. Thus, changing the proportion of gamma dose with a Bi or Pb filter changes the radiation quality more significantly than modifying the neutron spectrum by moderation or filtration. (A.K.)