Preliminary Design Of The Bunch Length Measurement System For NSRL Injector

With the development of design and construction technology in accelerator field, high-quality beam brings challenges to beam diagnostics. In order to adapt to the strict requirements, new beam measurement techniques have emerged. Transverse Deflecting Structure(TDS) method with high precision, versatile, have obvious advantages. This paper aims to design a TDS Structure for longitudinal measurements. Basing on the work on TDS by scientists around the world, we designed a TDS cell structure--Disk loaded waveguide structure with two peripheral recesses matched to HLS injector parameters with CST software. The article gives detailed dimensions of the structure, the field type, the resulting dispersion curve. And the impact on the operating frequency of feature sizes are explicated. Beam dynamics simulations are executed by using MATLAB and PARMELA to show the evolution of the bunch distribution in the structure, respectively. MATLAB and PARMELA simulation are consistent.