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<專題討論>2018/12/20(四)14:10綜合大樓2樓48218教室演講 : 張博宇 助理教授(成功大學電漿所)

張貼者:2018年12月16日 下午6:38Dabby Lu
講題: Exploring space science, generating coherent x rays and neutrons via developing a metallic ion thruster and a pulsed-power system
摘要:Two independent projects are being conducted in Pulsed-Power Generator for Space Science (PGS) laboratory to study space science, generating coherent x rays and neutrons. One is to build a metallic ion thruster using magnetron e-beam bombardments. The other one is to build a pulsed-power system. For the metallic ion thruster, the principle of e-beam evaporations is used to generate ions. Ions are first generated from a metallic target being evaporated and ionized by thermal emission electrons and are accelerated by electric fields to provide the thrust. Different from inert gas used in conventional plasma thrusters, the metal target is in the solid state, high density, easy to be stored and cheap. A mass flow rate of 8.0 ± 1.3 µg/sec using Zn was measured. Therefore, let the parameter β be the ionization rate of the metal vapor, the estimated thrust is β mN with a power of 630 W assuming 5 kV accelerating voltage is used. The thrust is much larger than those provided from existing thrusters with similar powers to date. For the pulsed-power system, 6 kJ of energy is first stored in twenty 1 µF capacitors charged to 50 kV and is discharged to a load in a short period of time to provide high-power output. The preliminary data analysis of discharge test of two capacitors charged to 20 kV showed that a peak current of 30 kA was delivered. The extrapolated peak current of final design from this test is 500 kA with a rise time of 1 µs giving an output power of 10 GW. The system will be used to generate (1) plasma jets for studying space sciences specifically on interactions between solar winds and unmagnetized planets using conical wire arrays; (2) soft x-ray laser using capillary z-pinch; and (3) neutrons using dense plasma focus. Status of developments for both projects and proposed research topics will be introduced.
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Dabby Lu,
2018年12月16日 下午6:38
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