Nuclear Techniques ›› 2014, Vol. 37 ›› Issue (09): 90101-090101.

• SYNCHROTRON RADIATION TECHNOLOGY AND APPLICATIONS •

### Preliminary design of the bunch length measurement system for NSRL injector

ZHANG Hui ZHANG Shancai

1. (National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China)
• Received:2014-03-03 Revised:2014-04-08 Online:2014-09-10 Published:2014-09-09

Abstract: Background: With the development of design and construction technology in accelerator fields, high-quality beam brings challenges to beam diagnostics. Purpose: To meet the strict requirements, new beam measurement techniques have emerged. One of them is the Transverse Deflecting Structure (TDS) method that possesses advantages of versatility and high precision. This paper aims to design a TDS Structure for longitudinal measurements. Methods: Based on the work on TDS by scientists around the world, the Computer Simulation Technology-MICROWAVE STUDIO (CST-WS) software was applied to design a TDS cell structure-Disk loaded waveguide structure with two peripheral recesses matched to Hefei Light Source (HLS) parameters. Beam dynamics simulations are executed by using MATLAB and PARMELA to show the evolution of the bunch distribution in the structure, respectively. Results: Dimensions of this TDS, the field type and the resulting dispersion curve are obtained. And the impacts on the operating frequency of feature sizes are explicated. Conclusion: This structure can get the desired deflection field type. Stabilizing mode method can realize stable ~25.5 MHz frequency separation, which can be proved effective through CST simulations. Characteristic dimension b impacts the operating frequency most, and dr impacts changes most for different polarization modes. MATLAB and PARMELA simulation are consistent.