【摘要】 本文应用Ａｌ为阈探测器在兰州重离子研究装置（ＨＩＲＦＬ）的辐照终端上研究了７５ＭｅＶ／ｕ１２Ｃ离子束在辐射生物实验区产生的能量大于６ＭｅＶ的中子角分布。实验中束流经２４μｍ的Ｎｉ窗及由１０μｍ镀金的Ｍｙｌａｒ膜组成的平行板电离室后进入实验区，７个２０ｍｍ×５ｍｍ的阈探测器放置在距Ｎｉ窗２５ｃｍ处的不同角度上（６．５°～３６．０°），束流强度为３ｎＡ，活化样品测量用高纯锗探测器。结果表明，实验区产生的中子具有明显的前冲分布，测得的中子注量率分布，在与束流方向夹角６．５°～３６．０°范围内，大致呈指数衰减。这为进一步开展的重离子治癌研究提供了辐射防护的实验依据。更多还原

【Abstract】 The angular distribution of emitted neutron with energy greater than 6 MeV induced by 75 MeV/u 12 C ions in experiment area was measured with the activation method of Al threshold detector at irradiation terminal of HIRFL.The beams went through 24 μm Ni window, parallel plate ionization chamber with two 10 μm sold foiled Mylar film from the vacuum tube to experiment area. Seven Al threshold detectors were put at different positions (6.5°～36.0°), the distance was 25 cm from Ni window, the beam density was 3 nA. The data were obtained by high pure Ge(Li) detector. The results show that the angular distibution is strongly peaked in the forward direction, the distribution is exponential decay in experiment area. The data can be used in radiation protection for cancer therapy with heavy ions. (更多还原