Research On Power Supply System For Magnetic Field In THz Radiation Source

Terahertz(THz) wave is a sole portion of the electromagnetic spectrum which has yet not to be studied completely by scientists. As its unique properties may bring revolutionary breakthroughs in next generation communication technology, health and medical, basic research, it has become a hotpot since the end of last century. Up to now, all study about Thz technology including Thz source is still in the exploratory stage, and can not come into commercial application in a short time. In all types of Thz sources, gyrotron with repeated pulsed magnetic field is the best solution to realize high power output of THz wave, and power supply for repeated pulsed magnetic is necessary part in gyrotron. In this paper, a capcitor type power supply system for magnetic field in accordance with design rquirements”magnetic induction intensity 15 T, repetitive precision 0.3%, periode 1min".”Firstly, A complete system topology circuit with its hardware scheme are designed on the basis of LCC serial-parallel resonance circuit and thyristor discharge switch; To satisfy the repetitive precision of charging, charging process in each cycle is divided into several phases, and Pulse Frequency Modulation(PFM) is adopted as control method to adjust charging speed; System repeated operation procedrue and software scheme are also presented in the paper.During the operation of system, high-frequenct transformer parasitics may impose negative effect on charging mode, the paper designs a transformer by AP method to reduce its interference to an acceptable level to solve the problem; To collect accurate capacitue voltage signal as refferrence for charging speed, low temperature drift electronics including DC voltage divide, roperational amplifier and 24 bit analog-to-digital conversion chip are used to make up voltage acquisition circuit with theoretical precision of 0.1% by signal difference module amplifying principle.Finally, a sample device is made to conduct experiements, paper describes and analyzes abnomal situations during tests, figures out reasons, proposes improved opinions with effects, defines directions of further work in next stage.