Zanini A, Fasolo F, Visca L, Durisi E, Perosino M, Annand J R M, Burn K W
INFN Sez. Torino, V P Giuria 1, 10125 Torino, Italy.
Phys Med Biol. 2005 Sep 21;50(18):4287-97. doi: 10.1088/0031-9155/50/18/004. Epub 2005 Aug 31.
A passive system for neutron spectrometry has been tested in view of neutron dose evaluation in mixed radiation fields. This system, based on bubble detectors (Bubble Technology Industries, Ontario, Canada), is suitable to evaluate the neutron energy distribution in the range 10 keV-20 MeV even in the presence of intense gamma radiation, as required in various fields: medical x-ray accelerators, nuclear reactors, cosmic ray exposures on commercial high-altitude flights and space missions. A new unfolding code BUNTO has been especially developed for this application. In the present work, the results of two experimental tests are summarized. In the first one, the device has been exposed to a standard AmBe neutron source (Joint Research Centre, Ispra, Varese, Italy). In the second one, measurements have been carried out at the MAX-Lab photonuclear facility in Sweden, with a bremsstrahlung photon beam impinging on thick targets of different materials and generating a giant dipole resonance neutron spectrum. Simulations of the experimental apparatus have been performed with MCNP4B (AmBe source) and with MCNP4B-GN (MAX-Lab). Results of the comparison between experimental and calculated spectra are shown and discussed. A good agreement between measurements and simulation data is obtained in both the experiments.
为了评估混合辐射场中的中子剂量，对一种用于中子能谱分析的被动系统进行了测试。该系统基于气泡探测器（加拿大安大略省气泡技术工业公司），即使在存在强伽马辐射的情况下，也适用于评估10 keV至20 MeV范围内的中子能量分布，这在各个领域都是需要的：医用X射线加速器、核反应堆、商业高空飞行中的宇宙射线照射以及太空任务。为此应用专门开发了一种新的解谱代码BUNTO。在本工作中，总结了两项实验测试的结果。在第一项测试中，该装置暴露于标准的镅铍中子源（意大利瓦雷泽省伊斯普拉市联合研究中心）。在第二项测试中，在瑞典的MAX-Lab光核设施进行了测量，用轫致辐射光子束撞击不同材料的厚靶并产生巨偶极共振中子谱。用MCNP4B（用于镅铍源）和MCNP4B-GN（用于MAX-Lab）对实验装置进行了模拟。给出并讨论了实验谱与计算谱之间的比较结果。在两项实验中，测量结果与模拟数据都取得了良好的一致性。
