基于TPC的快中子能谱测量方法的研究

快中子能谱的测量在许多领域都有着广泛的应用，如何同时实现较高的探测效率及能量分辨率一直是该领域研究人员努力的方向，并相应的发展了许多方法，其中应用较为广泛的一种就是质子反冲望远镜方法。其发展、改进方向有二：一是采用以含H气体为工作介质的气体电离室，以克服质子在固体转换膜中的能量损失不一致造成的能量分辨率的劣化；二是采用较大面积的探测器来测量反冲质子，以增大探测效率，但鲜有能同时解决以上两个问题的方法。本课题提出了一种全新方法：基于TPC的快中子能谱测量方法，采用含H工作气体，充分利用TPC的优势，给出反冲质子在气体中的所有信息，包括径迹方向、能量损失等，反演出入射中子的能量。它将具有能量分辨率高（以气体为转换体）、效率高（整个TPC端部都为反冲质子灵敏探测区域）、n/gamma抑制比和其它本底扣除能力（径迹特点不同）等优点。本项目将对该方法进行理论和实现研究，对快中子能谱实现较高水平的测量

Fast neutron spectrometer is widely used in many field. How to achieve high energy resolution and detection efficiency in the meantime is the direction of many studies. Many methods were developed, and proton recoil telescope is one of the most widely used ones. In this direction, the research efforts can be divided into two classes: one is to apply the proportional gas detector filled with hydrogenous gas to avoid the worsen of energy resolution caused by the energy loss in the solid convertor film;the other one is to use detector with larger proton detection area to increase the detection efficiency. But most of them still need further improvement..In this proposal, a novel methods is proposed: a fast neutron spectrometer based on TPC. When filled with hydrogenous gas, TPC can give out many information of the recoiled proton, including direction of proton trajectory, dE/dx,and total energy deposit, and then the energy of the neutron can be determined. Following advantages are expected for this system: higher energy resolution because of the adoption of gas convertor; higher detection efficiency due to the larger detection area; and good n/gamma and background discrimination due to particle identification ability of TPC. This project will study this method based on simulation and experiment, and to implement the energy measurement of fast neutron with high energy resolution and detection efficiency in the meantime.