用于中子照相的定向高通量中子发生器设计  

Novel Type of Neutron Generator for Neutron Radiography

作　　者：唐君[1] 何小海[1] 娄本超[1] 曹超[1] 张钦龙[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621900

出　　处：《真空科学与技术学报》2015年第3期362-366,共5页Chinese Journal of Vacuum Science and Technology

基　　金：中国工程物理研究院中子物理学重点实验室资助课题(2012BC01;2012BB03)

摘　　要：近几年,在无损探伤领域,中子照相技术发展非常迅猛,对中子发生器提出了体积小、寿命长、通量高、准直比高的技术要求。为此设计了一台用于快中子照相的定向高通量小型中子发生器,采用矩形结构潘宁离子源。引出的具有一定长度和流强的带状氘离子或氘氚混合离子束,在离子源与靶构成的同轴高压电场加速下,轰击对应的长形定向自成靶,发生氘氘或者氘氚反应,在靶轴线方向产生高通量、高准直比的快中子束,中子产额5×1011n/s。模拟结果表明,成像屏上的中子注量提高了两个数量级,不均匀度小于5×10-3,满足中子照相对高准直比和高通量的要求,因此成像质量高,照相时间短,工作效率高。解决了现有中子发生器体积大、有效中子通量低和靶寿命短的问题,可用于构建移动式快中子照相系统。A novel type of mobile neutron generator, dedicated to neutron radiography, was developed. The original work includes extraction of a wide ribbon-shaped D and/or D/T ion beams from rectangular Penning ion-source with an array of side-holes and bombardment of long slightly-tilted coaxial target, to generate high yield of neutron beam because the limitations on ion beam intensity and on deposition power of target were removed. The impact of the Penning-source/ target alignment on ion-beam transport was mathematically modeled, theoretically analyzed and numerically simulated with software PIC. The simulated results show that the neutron fluence on imaging screen increases by two-order of magnitude and its unevenness drops down to less than 5%c. The newly-developed compact neutron generator, with strengths including small size, long life, large flux, and high collimation ratio, is capable of providing a neutron yield of 5 × 10^11 n/s and satis- fying the requirements of neutron radiography.

关 键 词：中子发生器 高通量 小型 中子照相 

分 类 号：TL501[核科学技术—核技术及应用]