Particle - Identified Spectroscopy with Phoswich Detector in High-Energy Mixed Radiation Field

在航天器或飞机上几乎没有测量过中子谱，因为中子测量需要区分中子和带电粒子事件。基于这一观点，我们研制了一种由NE213液体闪烁体(直径133 mm)组成的新型光敏探测器。X 133 mm长)，周围环绕着一个NE115塑料闪烁体(10 mm厚)。NE115闪烁体中带电粒子产生的光具有225毫微秒的长特征衰减时间常数，而NE213闪烁体中中子反冲质子产生的光具有30毫微秒的时间常数。光衰减时间常数的这些差异使分离不同粒子种类的脉冲成为可能。该探测器通过区分空间混合场中的中子和带电粒子事件，可以测量高达130 MeV的中子谱。在近红外…上，用70 MeV的质子轰击2 mm厚的Be靶，产生了中子和带电粒子的混合场更多(国家放射科学研究所)回旋加速器设施，并通过轰击100 MeV/n的碳离子停止长度的碳或铝靶在千叶重离子医疗加速器(HIMAC)在NIRS。探测器放置在靶体下游3~5m处，0~45度处。至光束轴线。该探测器能够区分中子和伽马射线事件和入射带电粒子事件。用RIKEN(Institute Of Physitive And Chemical Research)环形回旋加速器的135 MeV质子轰击Be+C靶上的中子，测量了该探测器对中子的响应函数。将测得的中子响应函数与蒙特卡罗计算、SCINFUL程序进行了比较。根据这些实验和计算的响应函数，完成了130 MeV以下中子的响应矩阵。用FERDOU程序展开实验能谱，得到了近红外回旋加速器中子和带电粒子混合场的伽马射线能谱和中子能谱。较少

Neutron spectra have scarcely been measured on board a spacecraft or an aircraft, because the neutron measurement requires a discrimination between neutron and charged-particle events. In this viewpoint, we have developed a new phoswich detector consisting of an NE213 liquid scintillator (133mm diam. X 133mm long) surrounded by an NE115 plastic scintillator (10mm thickness). The light induced by charged particles in the NE115 scintillator has a long characteristic decay time constant of 225nsec, whereas the light by recoil protons from neutrons in the NE213 has the time constant of 30nsec. These differences in the light-decay time constant make it possible to separate pulses of the different particle species. This detector can measure the neutron spectrum up to about 130MeV by discriminating between neutron and charged-particle events in a mixed field in space.A mixed field of neutrons and charged particles were produced by bombarding 70MeV protons on a 2mm thick Be target at the NIRS … More (National Institute of Radiological Sciences) cyclotron facility and by bombarding 100MeV/n carbon ions on stopping length carbon or aluminium target at the HIMAC (Heavy Ion Medical Accelerator in Chiba) in the NIRS. The detector was placed at 3〜5m downstream from the target at 0〜45deg. To the beam axis. It was found that this phoswich detector was able to discriminate neutron and gamma-ray events from incident charged-particle events.The response functions of the phoswich detector to neutrons were measured with neutrons from the Be+C target bombarded by 135MeV protons from the RIKEN (Institute of Physical and Chemical Research) ring cyclotron. The measured response functions for neutrons were compared with Monte Carlo calculations, SCINFUL code. From these experimental and calculated response functions, the response matrices were completed for neutrons up to 130MeV. By unfolding the experimental spectra with the FERDOU code, the gamma-ray and neutron spectra in a mixed field of neutrons and charged particles at NIRS cyclotron were obtained. Less