初始裂变产物鉴别技术研究

项目名称： 初始裂变产物鉴别技术研究

项目编号： No.11475271

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 刘世龙

作者单位： 中国原子能科学研究院

项目金额： 98万元

中文摘要： 初始裂变产物核的质量、动能、电荷分配情况是裂变反应的重要特征，可反映裂变发生初始时刻丰中子核的质量分布、能量分布及瞬发中子多重性等重要裂变信息。实现初始裂变产物核直接鉴别有助于深入了解裂变过程，核裂变电荷分布及产额能量关系系统学规律等。随着核能开发技术的进步，新一代反应堆和加速器驱动核能装置在设计时非常需要裂变核初始裂变产物产额数据。本研究工作拟建立一套双臂重离子鉴别测试系统，对于裂变产物核质量分辨A/ΔA大于100，电荷分辨Z/ΔZ大于40，使其能够运用于初始裂变产物离子直接鉴别，为裂变物理基础研究、核能开发建立新的测试方法。技术方案是采用微通道板探测器精确测定初始裂变产物粒子飞行时间，布拉格气体探测器测定产物粒子动能和比电离峰值，通过粒子飞行时间和布喇格探测器沉积的动能确定产物核的质量数A，布喇格峰值信息测定产物核的电荷数Z，实现初始裂变产物直接鉴别。

中文关键词： 粒子鉴别；初始裂变产物；时间分辨；能量分辨；飞行时间探测器

英文摘要： In low-energy fission of actinides ,the nuclear split two fragments,at the same time emission prompt-neutron and gamma-ray. The fragements mass energy and charge distributions are important features for fission process research.It was associated with the structure of fissile nuclear ,fission mechanism and systemic rule of charge distribution.With the development of nuclear engergy exploitation,next generation reactors and accelerator drive energy system need more information about fission fragement on device designing ,especially for independed fission yield and delayed neutron data.Therefore,developing a new approach to measure mass energy and charge distributions of fission fragments with high resolution prior to after prompt-neutron emission is indispensable!In this work,we plan to establish one system with two arms for heavy ion species determination in fission fragments.we hope the mass resolution A/ΔA better than 100,and charge resolution Z/ΔZ better than 40 for fission fragments.Hence,this system could be used to fission fragments species direct indentification.It's a new approach for fission fragments measurement,by this technique could research fission process deeply and precise fission-fragment decay studies,also achieve independed fission yields measure future nuclear energy exploitation. This project planning Dual-speed and Dual -kinetic energy associated measurement techniques to realize the fission products particle identification.Micro-channel plate as the time detector for flight time determine, Bragg gas ionization chamber as fragment kinetic energy and ionization ratio determine. Associated the particle flight time and kinetic energy information could confirm fission fragment mass number A ,Bragg detector energy peak value could confirm charge number Z.

英文关键词： particle identification;fission fragment;time resolution;energy resolution;flight time detector