Badhwar Gautam D
NASA Johnson Space Center, Houston, Texas 77058-3696, USA.
Radiat Res. 2002 Jan;157(1):69-75. doi: 10.1667/0033-7587(2002)157[0069:srdmit]2.0.co;2.
The International Space Station (ISS) is now a reality with the start of a permanent human presence on board. Radiation presents a serious risk to the health and safety of the astronauts, and there is a clear requirement for estimating their exposures prior to and after flights. Predictions of the dose rate at times other than solar minimum or solar maximum have not been possible, because there has been no method to calculate the trapped-particle spectrum at intermediate times. Over the last few years, a tissue-equivalent proportional counter (TEPC) has been flown at a fixed mid-deck location on board the Space Shuttle in 51.65 degrees inclination flights. These flights have provided data that cover the expected changes in the dose rates due to changes in altitude and changes in solar activity from the solar minimum to the solar maximum of the current 23rd solar cycle. Based on these data, a simple function of the solar deceleration potential has been derived that can be used to predict the galactic cosmic radiation (GCR) dose rates to within +/-10%. For altitudes to be covered by the ISS, the dose rate due to the trapped particles is found to be a power-law function, rho(-2/3), of the atmospheric density, rho. This relationship can be used to predict trapped dose rates inside these spacecraft to +/-10% throughout the solar cycle. Thus, given the shielding distribution for a location inside the Space Shuttle or inside an ISS module, this approach can be used to predict the combined GCR + trapped dose rate to better than +/-15% for quiet solar conditions.
随着国际空间站（ISS）上开始有人类长期驻留，它已成为现实。辐射对宇航员的健康和安全构成严重风险，因此在飞行前后估算他们的辐射暴露量有着明确的要求。由于没有办法计算中间时刻的捕获粒子能谱，所以无法预测太阳活动极小期或极大期之外其他时刻的剂量率。在过去几年里，一个组织等效正比计数器（TEPC）在航天飞机中舱的一个固定位置随航天飞机进行了倾角为51.65度的飞行。这些飞行所提供的数据涵盖了由于海拔变化以及从当前第23个太阳活动周期的太阳活动极小期到极大期太阳活动变化而导致的剂量率预期变化。基于这些数据，推导出了一个简单的太阳减速势函数，该函数可用于预测银河宇宙辐射（GCR）剂量率，误差在±10%以内。对于国际空间站所覆盖的海拔高度，发现捕获粒子造成的剂量率是大气密度ρ的幂律函数ρ^(-2/3)。这种关系可用于在整个太阳活动周期内预测这些航天器内部的捕获剂量率，误差在±10%以内。因此，在太阳活动平静的条件下，给定航天飞机内部或国际空间站舱内某一位置的屏蔽分布，这种方法可用于预测GCR与捕获剂量率之和，误差优于±15%。
