一个高灵敏度中子扫描变像管的设计

THE DESIGN OF A NEUTRON STREAK IMAGE TUBE WITH HIGH DETECTION EFFICIENCY

设计了一个高探测灵敏度的中子扫描变像管，该管采用电子产额较高的聚乙烯加磺化中子阴极。承极面积大（Х１０ｍｍ），不设置狭缝，电子束的交叉截面聚焦于ＭＣＰ的前表面。设计时间分辨率为４３ｐｓ，探测产额大于１×１０＾８个烧蚀靶内焊中子，当靶到阴极距离方几十厘米时，也可用于测量爆推靶内爆中子能谱多普勒展宽，从而确定等离子体离子温度。

A neutron streak image tube has been designed with high detection efficiency. The largearea photocathode (10 mm) consists of CsI on an Al foil, which is backed with a piece of polyethylene. Thetube has no slit and the cross-over of the electron beam is focused on the front surface of the MCP. The calculated time resolution is 43 ps for 14. 1 MeV neutrons. It is estimated that our tube can record signals fromthe implosion of DT-filled targets producing yields of 1 10~8 neutrons with a target to photocathode distanceof 5cm. The neutron streak image tube also can be used to determine the temperature of the plasma of theimplosion of DT-filled targets by measuring the Doppler broadening.