Nuclear Techniques ›› 2014, Vol. 37 ›› Issue (05): 50102-050102.doi: 10.11889/j.0253-3219.2014.hjs.37.050102


Research on application of Libera Photon processor for XBPM in SSRF

LIU Zhanjun1,2 XU Huichao1 GONG Peirong1   

  1. 1(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Zhangjiang Campus, Shanghai 201204, China) 2(University of Chinese Academy of Sciences, Beijing 100049, China)
  • Received:2014-03-26 Revised:2014-04-15 Online:2014-05-10 Published:2014-05-08


Background: The X-ray Beam Position Monitor (XBPM) is an important device to measure the X-ray position of synchrotron radiation beamline. Previous signal processing unit of XBMP at Shanghai Synchrotron Radiation Facility (SSRF) beamline is based on I/V converter and Analog to digital converter (ADC) module E2240 manufactured by MOXA which results in low spatial resolution and insufficient data acquisition rate. Purpose: In order to improve the performance of XBMP at SSRF, an upgrading of the XBPM is undertaken by using new all-in-one processor. The application of this new processor is briefly described in this paper. Methods: In the hardware side, a new generation digital BPM processor Libera Photon is adopted which can achieve a best position resolution of 0.01 μm and provides two parallel data paths that operate at different frequencies for flexible process. In the software side, relevant EPICS interfaces are modified in both Operator Interface (OPI) level and Input/output Controller (IOC) level to coordinate the new processor according to the control requirements. Results: The upgraded system can capture XBMP signal change within 2 ms by using the Fast Acquisition (FA) dataflow at approximately 10 kHz, which can be used for fast feedback control. Observed Slow Acquisition (SA) dataflow is typically around 10Hz, which can be used to monitor long-time signal changes and predict the varying trend of beam position. Conclusion: Libera Photon processor is successfully applied to the XBMP at SSRF beamline to achieve high position resolution and feasible control requirements.

Key words: X-ray Beam Position Monitor (XBPM), EPICS, Libera Photon, Data acquisition