Engineering Application Research Of High Coulomb And High Current Gas Spark Switch

Switching technology is the most important of pulsed power technology, a high-energy switch with high voltage, high current, large charge-transfers, slight electrodes erosions, long life-time and highly reliability is greatly expected to meet the main amplifier laser fusion energy systems. In this thesis the system of the high coulomb and high current gas spark switch is fully explored.This thesis initiates with the review of switches with used in main amplifier laser fusion, including the operating principles and the recent development trend of high power pulse closing switches. According to practical condition of engineering, a two-electrode gas spark switch is introduced in this thesis.According to the special requirements for two-electrode gas spark switch, the system of high current switch included following four parts: gas spark switch, magnetic switch, trigger system and gas control system.Improve the electrodes erosion; life-time and reliability of switch are the most important research of the high coulomb and high current switch. This paper discusses the design of the two electrodes switch in the aspects of the electrode material, electrode shape, insulation shell, and the insulation gas.The two-electrode switch has eliminated trigger electrode, the trigger system must output a very high voltage to trigger the switch. In order to protection the energy systems and other key components, the discharge circuit must use a magnetic switch. This paper discusses the operating principle of magnetic switch, the special requirements of magnetic materials. According to the engineering application conditions, magnetic materials selection and structural of magnetic switch have been designed and completed.One kinds of trigger system which used 6 steps of Marx generator is designed. The trigger voltage achieved 120kV, and the rise time was less than 30ns. In order to reduce the inductance of Marx generator discharge circuit, the Marx generator using a low-inductance capacitors and coaxial structure. Adopt optic fiber to control the trigger system, and the results indicate that the fiber-trigger mode is more stably and safely.The operating principle of gas control system is introduced. According to practical condition of engineering, the elementary experiments indicate the self-breakdown voltage of the switch is about D.C. 50kV. The peak current of the switch is near 300 kA with a transfer-charge of 100 coulombs. 200 times of experiments of the switch indicate that erosions on the electrodes are slight and the system of high current switch is safe and reliable.More than 1500 times long lifetime experiments of switch, the consistency, dispersion and reliability of multiple switch systems and the electromagnetic compatibility of power modules of SGâ…¢are going to be developed in the future.