Heinrich W, Wiegel B, Ohrndorf T, Bücker H, Reitz G, Schott J U
University of Siegen, Department of Physics, Federal Republic of Germany.
Radiat Res. 1989 Apr;118(1):63-82.
Measurements of cosmic-ray LET spectra were part of the radiobiological space research programs during the Spacelab 1 (SL-1) and the D1 missions. We analyzed CR-39 plastic nuclear track detectors of the Advanced Biostack experiment of SL-1 and of the Dosimetric Mapping and Carausius morosus experiments in the BIORACK on D1. The particle tracks in the CR-39 were detected and measured by an automatic scanning and measuring system. An in-flight calibration was derived from track measurements of minimum ionizing oxygen and iron nuclei and of stopping nuclei as a function of the residual range. LET spectra measured at different locations in the space shuttle are presented and discussed for both missions. A model describing the effects of the geomagnetic field of the earth on charged cosmic-ray particles and the shielding by matter is used to calculate LET spectra for the two missions and for typical space station orbits at low inclinations. A comparison of measured LET spectra and LET spectra calculated for different flight parameters shows that besides geomagnetic shielding the shielding by matter is most important in comparison to solar modulation and to variation of particle flux with flight altitude. Model calculations must be improved and must consider more detailed sectored shielding by matter and the influence of trapped radiation. The last item is of importance in the case of low-inclination orbits.
宇宙射线传能线密度（LET）谱的测量是“空间实验室1号”（SL - 1）和“D1”任务期间放射生物学空间研究计划的一部分。我们分析了SL - 1的高级生物堆实验以及D1上生物舱中剂量测绘和桑蚕实验的CR - 39塑料核径迹探测器。CR - 39中的粒子径迹由自动扫描和测量系统进行检测和测量。通过对最低电离氧和铁原子核以及作为剩余射程函数的停止原子核的径迹测量得出飞行中的校准值。针对这两项任务，展示并讨论了在航天飞机不同位置测量的LET谱。使用一个描述地球地磁场对带电宇宙射线粒子的影响以及物质屏蔽作用的模型，来计算这两项任务以及低倾角典型空间站轨道的LET谱。对测量的LET谱与针对不同飞行参数计算的LET谱进行比较表明，与太阳调制以及粒子通量随飞行高度的变化相比，除了地磁屏蔽外，物质屏蔽最为重要。必须改进模型计算，并且必须考虑更详细的物质扇形屏蔽以及捕获辐射的影响。最后一项在低倾角轨道的情况下很重要。
