HLS直线加速器条带束流位置检测器基于对数比方法的标定

Mapping of Strip Line Beam Position Monitor at HLS LINAC Based on Logarithm Ratio Processing Method

摘要: 对合肥光源（HLS）直线加速器（LINAC）的束流位置测量系统进行改造，设计并加工了非拦截型、高精度的条带电极束流位置检测器（Beam Position Monitor, BPM）。安装前，通过定位精度小于5 μm的电控位移平台，采用具有更大动态范围和线性度的对数比而非传统的差和比的处理方法，对条带束流位置检测器进行标定。本文介绍了标定平台、对数比处理系统以及自动控制标定程序，给出了基于对数比方法的标定结果。该条带电极束流位置检测器的水平方向和垂直方向的灵敏度分别为1.55 dB/mm和1.48 dB/mm，束流位置分辨率为42 μm，电中心相对于机械中心的偏差为（0.212，0.450） mm。

Abstract: A non-interceptive precise strip line beam position monitor (BPM) for HLS LINAC was redesigned. Before installation, a mapping of strip line BPM was carried out on a workbench with a precision of less than 5 μm, based on logarithm ratio method, which has a larger dynamic range and linearity than traditional ration between difference and sum. The mapping workbench, logarithm ratio processing system and automatic mapping program were described. The results of mapping are horizontal sensitivity of BPM system 1.55 dB/mm, vertical sensitivity 1.48 dB/mm, resolution of beam position 42 μm, offset between electronic center and mechanical one （0.212，0.450） mm.