Radiation dosimetry was carried out at the exposure facility (EF) and the pressurized module (PM) of the Japanese Kibo module installed in the International Space Station as one study on environmental monitoring for the Tanpopo mission. Three exposure panels and three references including biological and organic samples and luminescence dosimeters were launched to obtain data for different exposure durations during 3 years from May 2015 to July 2018. The dosimeters were equipped with additional shielding materials (0.55, 2.95, and 6.23 g/cm² mass thickness). The relative dose variation, as a function of shielding mass thickness, was observed and compared with Monte Carlo simulations with respect to galactic cosmic rays (GCRs) and typical solar energetic particles (SEPs). The mean annual dose rates were D_EF = 231 ± 5 mGy/year at the EF and D_PM = 82 ± 1 mGy/year at the PM during the 3 years. The PM is well shielded, and the GCR simulation indicated that the measured mean dose reduction ratio inside the module (D_PM/D_EF = 0.35) required ∼26 g/cm² additional shielding mass thickness. Observed points of the dose reduction tendency could be explained by the energy ranges of protons (10–100 MeV), where the protons passed through, or were absorbed in, the shielding materials of different mass thickness that surrounded dosimeters.

中文翻译：

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坦波波任务国际空间站曝光设施的空间辐射剂量测定

作为 Tanpopo 任务环境监测的一项研究，在国际空间站中安装的日本 Kibo 模块的照射设施 (EF) 和加压模块 (PM) 进行了辐射剂量测定。推出了三个曝光面板和三个参考，包括生物和有机样品以及发光剂量计，以获取 2015 年 5 月至 2018 年 7 月 3 年期间不同曝光持续时间的数据。剂量计配备了额外的屏蔽材料（0.55、2.95 和 6.23 g/ cm ²质量厚度）。观察到作为屏蔽质量厚度函数的相对剂量变化，并与有关银河宇宙射线 (GCR) 和典型太阳高能粒子 (SEP) 的蒙特卡罗模拟进行比较。年平均剂量率为在 3 年期间，EF 时D _EF  = 231 ± 5 mGy/年， PM 时D _PM  = 82 ± 1 mGy/年。PM 被很好地屏蔽，GCR 模拟表明模块内部测量的平均剂量减少比（D _PM / D _EF  = 0.35）需要~26 g/cm ²额外的屏蔽质量厚度。观察到的剂量减少趋势点可以用质子的能量范围（10-100 MeV）来解释，其中质子穿过或被吸收在剂量计周围的不同质量厚度的屏蔽材料中。