Attix F H, Theus R B, Miller G E
Phys Med Biol. 1976 Jul;21(4):530-43. doi: 10.1088/0031-9155/21/4/005.
Attenuation measurements have been made for pressed wood, steel and lead in the neutron beam generated by 35 MeV deuterons on a thick Be target, using narrow-beam, semibroad-beam and broad-beam geometries. In addition, the measurements were extended to the neutron beams from 25 and 15 MeV D+ on Be, for semibroad-beam geometry only. A tissue-equivalent plastic ionization chamber was used as the detector; hence the measured parameter approximated the total (n + gamma) dose in tissue. After correcting for radiation scattering around the absorbers, the remaining curves were nearly exponential in most cases, and a build-up factor could be employed to describe the varying degree of scattered radiation dose as a function of absorber thickness and geometry. The results given should be applicable in designing primary-beam shields and collimators, as well as providing a useful basis for extending calculations to other geometries through Monte Carlo techniques.
利用窄束、半宽束和宽束几何条件，对35兆电子伏特氘核轰击厚铍靶产生的中子束中的压制木材、钢和铅进行了衰减测量。此外，测量仅扩展到半宽束几何条件下，25兆电子伏特和15兆电子伏特氘核轰击铍产生的中子束。使用组织等效塑料电离室作为探测器；因此，测量参数近似于组织中的总（中子 + γ）剂量。在对吸收体周围的辐射散射进行校正后，大多数情况下剩余曲线近似呈指数关系，并且可以采用积累因子来描述散射辐射剂量随吸收体厚度和几何形状的变化程度。给出的结果应适用于设计初级束屏蔽和准直器，以及为通过蒙特卡罗技术将计算扩展到其他几何条件提供有用的基础。
