用于测量强流脉冲电子束的B-dot

B-dot monitor for intense electron beam measurement

描述了B-dot探头测量脉冲电子束流强度和束质心位置的原理,分析了B-dot探头工作于自积分和微分模式的条件,并根据所测电子束流信号的前沿和脉冲宽度特点,确定B-dot探头工作于微分模式,设计其电感参数约为60 nH。在电子束流模拟装置上对B-dot探头的灵敏度系数和偏心曲线进行了标定,标定得到B-dot探头及测试线路的灵敏度系数为4 147 A/V。将探测器安装在神龙一号加速器上进行束测实验,多次实验结果表明该探测器可以实现电子束流强度和质心位置的准确测量。

Azimuthal arrays of B-dot loops are often used to measure the time-resolved beam centroid position of a pulsed, intense electron beam propagating in a metallic tube. This paper describes the designing principle, parameters and calibration of the B-dot monitors. According to the beam current pulse rise time, fall time and the pulse width,the B-dot is designed to work as a differential loop, the loop inductance is about 60 nil. The B-dot monitor＇s sensitivity and the displacement curve are calibrated in the test stand. The sensitivity of the B-dots and the passive RC integrator is averagely 4 147 A/V, integrate constant is about 1 Vs. The B-dot monitors are used to measure the Dragon-Ⅰ electron beam and the experimental results show that the B-dot monitors can measure the beam current and centroid position accurately.