Scampoli P, Durante M, Grossi G, Manti L, Pugliese M, Gialanella G
Department of Physics, University Federico II, and INFN, Sezione di Napoli, Monte S. Angelo, Via Cintia, Napoli, Italy.
Adv Space Res. 2005;35(2):230-5. doi: 10.1016/j.asr.2005.01.046.
We measured fluence and fragmentation of high-energy (1 or 5 A GeV) 56Fe ions accelerated at the Alternating Gradient Synchrotron or at the NASA Space Radiation Laboratory (Brookhaven National Laboratory, NY, USA) using solid-state CR-39 nuclear track detectors. Different targets (polyethylene, PMMA, C, Al, Pb) were used to produce a large spectrum of charged fragments. CR-39 plastics were exposed both in front and behind the shielding block (thickness ranging from 5 to 30 g/cm2) at a normal incidence and low fluence. The radiation dose deposited by surviving Fe ions and charged fragments was measured behind the shield using an ionization chamber. The distribution of the measured track size was exploited to distinguish the primary 56Fe ions tracks from the lighter fragments. Measurements of projectile's fluence in front of the shield were used to determine the dose per incident particle behind the block. Simultaneous measurements of primary 56Fe ion tracks in front and behind the shield were used to evaluate the fraction of surviving iron projectiles and the total charge-changing fragmentation cross-section. These physical measurements will be used to characterize the beam used in parallel biological experiments.
我们使用固态CR - 39核径迹探测器，测量了在交变梯度同步加速器或美国国家航空航天局空间辐射实验室（美国纽约布鲁克海文国家实验室）加速的高能（1或5 A GeV）56Fe离子的注量和碎片化情况。使用了不同的靶材（聚乙烯、聚甲基丙烯酸甲酯、碳、铝、铅）来产生大范围的带电碎片。CR - 39塑料在垂直入射且低注量的情况下，放置在屏蔽块（厚度范围为5至30 g/cm²）的前后进行辐照。使用电离室在屏蔽块后方测量存活的铁离子和带电碎片沉积的辐射剂量。利用测量得到的径迹尺寸分布来区分初级56Fe离子径迹和较轻的碎片。测量屏蔽块前方入射粒子的注量，以确定屏蔽块后方每个入射粒子的剂量。同时测量屏蔽块前后的初级56Fe离子径迹，以评估存活铁弹丸的比例和总电荷变化碎片化截面。这些物理测量将用于表征在并行生物实验中使用的束流。
