储存环中快速束团横向尺寸检测器的设计

Design of fast beam transverse profile monitor in electron storage ring

一种利用可见光的快速束团横向尺寸检测器(Fast Beam Transverse Profile Monitor,FBPM)正在研制过程中,并用于测量快速束流位置和尺寸,该装置将应用到升级改造完成后的合肥光源。FBPM基于日本滨松公司生产的多阳极光电倍增管(Multi-Anode Photo-Multiplier Tube,MAPMT)R5900U-00-L16,它每个通道拥有的有效感光区域为0.8 mm?16 mm,典型上升时间为0.6 ns,因此拥有足够的空间分辨率和时间分辨率。本文介绍了同步光成像系统,设计了低噪声宽带前置放大器,基于光电倍增管4个相邻通道设计了对数处理算法。离线测试结果表明,透镜焦距的测量误差小于?1 mm,放大器带宽达到420 MHz,4个通道相对参考通道2的增益偏差小于0.2 d B,4通道峰值信号偏差不超过2%。

Background： Many issues such as beam dynamics and beam instability concerning machine performance and stability are being studied in accelerator facility. As a consequence, a Fast Beam Transverse Profile Monitor （FBPM） using visible synchrotron radiation is being developed and will be applied for the upgrade project of Hefei Light Source （HLS II）. Purpose： This study aims to design a FBPM apparatus to measure beam position and size in electron storage ring. Methods： A Hamamatsu Multi-Anode Photo-Multiplier Tube （MAPMT） R5900U-00-L16 is applied to the development of FBME This MAPMT has a 0.8 mm^16 mm effective area per channel and 0.6 ns typical rise time which has enough spatial and temporal resolution. Logarithm processing technique with four successive channels is used to acquire beam parameters. Results： The test results show that measurement errors of focal length are within ＋l mm, bandwidth of low noise wideband amplifier is approximately 420 MHz, gain errors between all the four channels and the second channel are less than 0.2 dB, and peak signal errors among them are no more than 2%. Conclusion： The FBMP apparatus proposed in this paper meet the requirements of acquiring beam tttrn-by-turn transverse beam position and size with only four channels of MAPMT.