Sato Tatsuhiko, Endo Akira, Sihver Lembit, Niita Koji
Japan Atomic Energy Agency, 2-4, Shirakata-Shirane, Tokai, Ibaraki, 319-1195, Japan.
Radiat Environ Biophys. 2011 Mar;50(1):115-23. doi: 10.1007/s00411-010-0330-0. Epub 2010 Sep 11.
Absorbed-dose and dose-equivalent rates for astronauts were estimated by multiplying fluence-to-dose conversion coefficients in the units of Gy.cm(2) and Sv.cm(2), respectively, and cosmic-ray fluxes around spacecrafts in the unit of cm(-2) s(-1). The dose conversion coefficients employed in the calculation were evaluated using the general-purpose particle and heavy ion transport code system PHITS coupled to the male and female adult reference computational phantoms, which were released as a common ICRP/ICRU publication. The cosmic-ray fluxes inside and near to spacecrafts were also calculated by PHITS, using simplified geometries. The accuracy of the obtained absorbed-dose and dose-equivalent rates was verified by various experimental data measured both inside and outside spacecrafts. The calculations quantitatively show that the effective doses for astronauts are significantly greater than their corresponding effective dose equivalents, because of the numerical incompatibility between the radiation quality factors and the radiation weighting factors. These results demonstrate the usefulness of dose conversion coefficients in space dosimetry.
通过分别将单位为Gy·cm²和Sv·cm²的注量到剂量转换系数与单位为cm⁻²·s⁻¹的航天器周围宇宙射线通量相乘，估算了宇航员的吸收剂量和剂量当量率。计算中使用的剂量转换系数是通过将通用粒子和重离子输运代码系统PHITS与男性和女性成人参考计算体模耦合来评估的，这些体模作为ICRP/ICRU的一份共同出版物发布。航天器内部和附近的宇宙射线通量也由PHITS使用简化几何模型进行计算。通过在航天器内外测量的各种实验数据验证了所获得的吸收剂量和剂量当量率的准确性。计算定量表明，由于辐射品质因数和辐射权重因数在数值上不兼容，宇航员的有效剂量显著大于其相应的有效剂量当量。这些结果证明了剂量转换系数在空间剂量学中的有用性。
