Generation of Electron Beam and THz Transition Radiation in fs-THz Linac

DoctorTHz radiation is being used in various fields such as imaging, diagnosis, inspection, etc. For the THz research, the fs-THz facility has been constructed at the Pohang Accelerator Laboratory, which consists of a linear accelerator, a Ti:sapphire laser system, and a beamline room. The thesis concentrates on the linear accelerator composed of a photocathode RF gun, two accelerating columns, two chicane bunch compressors, and several quadrupole magnets and solenoids. The beam dynamics simulation has been studied by using the PARMELA code to determine the beam optics. Parameters of the linac components have been decided through the simulation to minimize the bunch length. The process of the electron bunch compression is shown in the thesis. The electron beam can be compressed to less than 100 fs passing through a chicane, and the result of the start-to-end simulation for the fs-THz linac is reported in the thesis. The fs-THz linac is currently accelerating electron beams for THz radiation generation using coherent transition radiation (CTR). The electron beam parameters, the beam energy, the energy spread, the beam charge, the transverse emittance and the bunch length have been measured. The experiments for the THz radiation pulse have been accomplished. The experimental results for THz CTR are analyzed with numerical calculations in the thesis