Preliminary Design Of A 15MeV Linac For THz Radiation Source

THz wave, with the particular frequency range from 100GHz to 10THz, is expected to be widely applied in industry, agriculture, medicine, biology and environment engineering. THz wave sources based on FEL has many unique advantages, which are hard to obtain by ordinary THz wave generator, so it takes an important role in THz wave applications.This paper introduces the preliminary design of a 15MeV linac for THz radiation sources. We employed a thermionic RF-Gun with an bunch compression system in the form ofα-magnet to produce eligible electron bunches. FORTRAN codes for beam dynamics simulation and parameters optimization of the Linac was developed.First, fundamentals and applications of THz wave are introduced, and several exiting THz wave sources are compared. The requirements of THz wave for Linac are obtained. Without bunch compression, acceleration is less effective and the results can't meet the THz standards.α-magnet has the abilities of energy selection and pulse compression, which is one of the effective ways to solve this problem. The achromatic entrance angle for n=1 ofα-magnet is verified. Particles'movement inα-magnet is simulated by numerical methods and the movement trajectories are presented, based on it an example is discussed. Then design of Linac is discussed also with calculation of disk-loaded cavities. An example is studied by my own codes. Last, the electrons starting from cathode till end are simulated unitary, and the preliminary parameters of 15MeV Linac is obtained through optimization.The deficiencies of my calculation and the future work are given out at the end of this dissertation.