Moslehi A, Raisali G
Radiation Applications Research School, Nuclear Science and Technology Research Institute, AEOI, PO Box 11365-3486, Tehran, Iran.
Radiat Prot Dosimetry. 2017 Nov 1;176(4):404-410. doi: 10.1093/rpd/ncx024.
To determine the dose-equivalent of neutrons in an extended energy range, in the present work a multi-element thick gas electron multiplier-based microdosemeter made of PMMA (Perspex) walls of 10 mm in thickness is designed. Each cavity is filled with the propane-based tissue-equivalent (TE) gas simulating 1 µm of tissue. Also, a few weight fractions of 3He are assumed to be added to the TE gas. The dose-equivalents are determined for 11 neutron energies between thermal and 14 MeV using the lineal energy distributions calculated by Geant4 simulation toolkit and also the lineal energy-based quality factors. The results show that by adding 0.04% of 3He to the TE gas in each cavity, an energy-independent dose-equivalent response within 30% uncertainty around a median value of 0.91 in the above energy range is achieved. It is concluded that after its construction, the studied microdosemeter can be used to measure the dose-equivalent of neutrons, favorably.
为了确定扩展能量范围内中子的剂量当量，在本工作中，设计了一种基于多元素厚气体电子倍增器的微剂量计，其由厚度为10毫米的聚甲基丙烯酸甲酯（有机玻璃）壁制成。每个腔室填充有模拟1微米组织的丙烷基组织等效（TE）气体。此外，假设向TE气体中添加了少量重量分数的³He。使用Geant4模拟工具包计算的线能量分布以及基于线能量的品质因数，确定了热中子到14 MeV之间11种中子能量的剂量当量。结果表明，通过在每个腔室的TE气体中添加0.04%的³He，在上述能量范围内，围绕0.91的中值，在30%的不确定度内实现了与能量无关的剂量当量响应。得出的结论是，在制造完成后，所研究的微剂量计可用于测量中子的剂量当量，效果良好。
