Comparison of the mean quality factors for astronauts calculated using the -functions proposed by ICRP, ICRU, and NASA

Sato, Tatsuhiko   ; Endo, Akira   ; Niita, Koji*

For the risk estimation of astronauts due to cosmic-ray exposure, not only organ absorbed doses but also their mean quality factors must be evaluated, since the radiation weighting factor is not suitable for use in space dosimetry due to its oversimplified concept. We therefore calculated the mean quality factors in organs and tissues in the ICRP reference voxel phantoms irradiated by various particles, using the PHITS code coupled with the ICRP, ICRU and NASA relationships. The isotropic irradiation was assumed in the calculation. The details of the calculation procedure will be presented at the meeting, together with the comparison between the mean quality factors obtained from the 3 relationships. The influence of the consideration of the track structure on the risk estimation will be also discussed.