长时间电流积分数字仪的设计

The development of a long-time current integration digitizer

本文介绍的长时间电流积分数字仪,是用电流-频率(I-F)转换电路将微弱电流转换成脉冲信号,结合后级脉冲计数器及处理控制电路,实现对10pA-10μA量级输入电流的长时间测量。该仪器可用于电离室、法拉第筒等输出电流或电荷的测量,测量时间范围1s-192h。该电路的设计实现,为长时间测量电流或电荷,并进行束流监测提供了一种可行、通用、高性价比的好方法。

A long-time current integration digitizer was developed for monitoring ion beams of the Heavy Ion Research Facility at Lanzhou （HIRFL）. A simple and practical method for current/frequency conversion was adopted, combined with a counter and processor. Being able to measure input currents of 10 pA-lO ~A, the long-time digital current integration instrument can be used for testing current or electrical charge from the ionization chamber, Faraday cup and other weak current sources. The time of measurement can be selected from 1 second to 192 hours （8 days）. The instrument can be operated in one cycle mode and recycle mode. A feasible, general, and cost-effective way for long time test of current or electrical charge was presented.