Analysis And Commissioning Of HLS Ⅱ New Injection System

Injection system is an important subsystem for the accelerator. Injection system is used to inject electron beams which are transfered to the end of transport line into the storage ring. It is a bond that connects the injector and the storage ring. The performance of injection system is closely related to the injection efficiency and transverse residual oscillation of the beam in the storage ring. It is also an important factor that affects the radiation dose in the light source area. By means of the simulations and experiments, qualitative and quantitative analysis to the error tolerances of HLSII are carried out. It provides an important reference for the commissioning and operation of Top-up in the future. At the same time, in view of the leakage of bump orbit which caused by the nonlinear effect, optimizing of the integral intensity of sextupoles is carried out to minimize the leakage of bump orbit.At first, the major renovation project of Hefei light source and the new injection system are introduced in the paper. Compared with the previous injection systems, the characteristics of the new injection system are elaborated. In addition, the components of the new injection system are described and the performances and characteristics of the components are analyzed in detail. The detailed physical analysis for the new injection system is also carried out in order to research the process of beam injection. At the same time, the relevant error analyses are done according to the actual situation of HLSⅡ. A series of tracking simulations are carried out under the condition of introducing errors, and obtains the tolerance of all kinds of errors.Some related experimental researches are carried out on the HLSⅡ. Under the condition of Decay mode, injection efficiency, beam transverse residual oscillation and radiation dose are measured. Second under the condition of introducing the deviations of kicker and septum, the injection efficiency and beam transverse residual oscillation are measured, and obtain the tolerance of deviations. Compared with the simulation result, the injection efficiency measured in the experiment is lower, but the variation trend is corresponding. This also verifies the validity of the simulations. The lower measured result may be due to the non-ideal factors which exist in the actual situation.Top-up is a unique operation mode that would be implemented in Hefei light source in the future. Preliminary Top-up commissioning is carried out during the commissioning of HLSII. At the onset of the commissioning, Top-up injection is interrupted frequently because of the breakdown of power source. This problem is solved successfully by adjusting the modulator and the microwave power source. At the same time, the radiation dose is monitored during Top-up injection. Contrapose the main problems existing in the commissioning of Top-up, some measures and methods for improvement are put forward.In addition, the nonlinear effect of sextupole is analyzed in detail, and minimizes the leakage of bump orbit by optimizing the integral strength of sextupole.