裂变碎片飞行时间测量技术的研究

	裂变碎片飞行时间测量技术的研究
Alternative Title	A Study on Time-of-Flight Technique for Detection of Fission Fragments
	孟庆华
Thesis Advisor	陈熙萌 ; 韩洪银
	2004-05-12
Degree Grantor	兰州大学
Place of Conferral	兰州
Degree Name	硕士
Keyword	252Cf(sf 裂变碎片 MCP＋SBD飞行时间技术探测效率时间分辨
Abstract	裂变碎片的质量鉴别是原子核自发裂变研究的主要方面，本硕士论文的研究工作在于：建立用于测量裂变碎片质量的 “微通道板（MCP）＋半导体探测器（SBD）”飞行时间探测系统，并研究其性能。在粒子的出射方向安装碳膜（80 g/cm2），当粒子穿过碳膜时所产生的次级电子经加速，然后被偏转栅偏转90°后入射到MCP，MCP的收集极给出事件发生的时间标志信号，作为飞行时间系统（TOF）的终止信号。穿过碳膜的裂变碎片飞行一段距离后，被SBD探测，经电荷灵敏前置放大器(ORTEC 142B)给出反映粒子动能的能量信号和反映其质量的TOF的起始信号。由KODAQ数据获取系统完成能量与飞行时间的两参量关联测量。经调试和检测，该系统对241Am的粒子的探测效率约为39%，对252Cf(sf)裂变碎片的探测效率约为98%。在EK= 78MeV条件下，探测系统对252Cf(sf)重裂变碎片（138amu-148amu）得到的时间分辨为224.1±6.1ps；在EK = 102MeV条件下，对252Cf(sf)轻裂变碎片（101amu-111amu）得到的时间分辨为154.5±5.8ps。本工作利用241Am的粒子对系统进行了时间刻度，用252Cf(sf)自转移源测量了裂变碎片产物质量谱。
Other Abstract	order to determine the mass of fragments in fission reaction, it is essential to develop a TOF( time-of-flight ) system. The purpose of this work is to set up a TOF detection system that include a micro-channel plate (MCP) and a semiconductor surface barrier detector (SBD), and study it. A carbon foil of 80 g/cm2 was mounted in the direction of the particle trajectories. The secondary electrons produced by particles passing through the carbon foil were accelerated, and then deflected by 90°onto MCP using an electrostatic mirror formed by two parallel grids. The stop signal of the TAC(time-to-amplitude converter ) was derived from the collecting anode of MCP. After flight a suitable distance, the projectiles impact on SBD. The charge-sensitive preamplifier (ORTEC 142B) associated with SBD provided the E signal related to the energy of particle and T signal as the start signal of the TAC related to the mass of particle. A two-parameter correlation measurement was completed in KODAQ data acquisition system. The TOF system shows a detection efficiency of 39% for particles released from 241Am and 98% for fragments in the spontaneous fission of 252Cf. The time resolutions are 224.1±6.1ps for the heavy fragments(EK=78MeV, AH=138amu-148amu) and 154.5±5.8ps for the light fragments(EK =102MeV, AL=101amu-111amu). Time calibration was completed using particles of 241Am. Mass spectra of the fission products were measured using 252Cf(sf) self-transfer source. "
URL	查看原文
Language	中文
Document Type	学位论文
Identifier	https://ir.lzu.edu.cn/handle/262010/229592
Collection	物理科学与技术学院
Recommended Citation GB/T 7714	孟庆华. 裂变碎片飞行时间测量技术的研究[D]. 兰州. 兰州大学,2004.

Files in This Item:
There are no files associated with this item.

If you have any objections to this item, please fill out the form below and the administrator will contact you as soon as possible.
Content:
Email：	*
Institution:
Verification Code:	Refresh

Any comments and suggestions are welcomed.
Title:	*
Content:
Email：	*
Verification Code:	Refresh

物理科学与技术学院知识库