北大4.5MV静电加速器束流脉冲化系统

４．５ＭＶ静电加速器是北大设计和建造的单级静电加速器。为了能够利用飞行时间法进行中子能量测量，需要把连续束变成短脉冲束。为此，在该器上配置了束流脉冲化系统。文章主要介绍４．５ＭＶ静电加速器束流脉冲化系统所采用的９ＭＨｚ射频聚束器和１．５ＭＨｚ射频切割器及有关的电子学线路、粒子纵向运动的模拟、对横向聚焦的要求。实验结果表明，可以获得的脉冲宽度为１．８ｎｓ。

BEAM PULSING SYSTEM FOR THE4.5 MV ELECTROSTATIC ACCELERATOR AT PEKING UNIVERSITY

The single stage 4.5 MV electrostatic accelerator was designed and constructed at PekingUniversity,P.R. China. In order to measure the neutron energy with time of flight method,it isnecessary to compress the continuous ion beams into pulsed beams. Therefore,a beam pulsingsystem is incorporated in this machine. The paper describes the 9 MHz rf bunching system,the1.5 MHz rf chopping system,the relevant electronics,the simulations of particle longitudinalmotions,the requirements to the transverse focusing system and the experimental results.1.8 nsduration of beam pulse width(FWHM)at the target is observed.