Simulation study of Cornell L0 beamline

To generate high quality synchrotron radiation in the future ERL light sources, the performance of the ERL injector, which has critical components, a photo cathode gun and super conducting cavities, is very important. In the injector, an electron beam is generated by photo cathode DC gun, and accelerated by super conducting RF cavities. Since an electron beam with −77 pC bunch charge and 1.3 GHz repetition rate has lower energy less than 15 MeV in the injector, space charge effect plays an important role in emittance compensation. The quality of electron beam depends on initial laser pulse, magnetic field of solenoid magnets and time dependent electromagnetic field in RF cavities. To generate high quality electron beam, these parameters are optimized using particle tracking simulation with space charge effect and multi objective method [1]. To obtain the minimum emittance at the exit of ERL injector beam line, beam simulations were carried using particle tracking code, Astra [2]. In this report, the optimization results to minimize normalized rms emittance and rms bunch length at the exit of injector are described. In this report, the components and field maps, which are in the injector beam line, are described in section 1.1. The initial particle distribution and optimization method are described in section 1.2 and 1.3, respectively. The optimization results are shown in section 1.4. Finally, the summary of the optimization is described in section 1.5. ∗E-mail address: [email protected]