一种新颖的微空心阴极放电等离子体推力器

微小卫星的发展和成功应用迫切需要新型微推力器的研制。微放电技术是等离子体放电中重要的一类,近几十年来成为各国的研究热点。其中,微空心阴极放电(MHCD)是一种新颖的非平衡高气压辉光放电,其优点是可以在高气压下稳定放电,并且只需要非常低的电压(几百伏特)或者输入功率(百毫瓦数量级)。MHCD建立在2个几百微米厚度的金属平面电极上,材料可以是钼、铝等,由电介质(云母或氧化铝)隔开。"三明治"的布局结构上从一个电极到另一个电极钻有直径为几十微米到几百微米的孔,气体压强可以很高,甚至超过大气压。微空心阴极放电较小的尺寸结构与强烈并可控的气体加热相结合,可以开发应用在新型的电热式微等离子体推进上。由于微空心阴极放电等离子体推力器在微放电等离子体中加热了工质气体,随后通过微喷管喷出产生推力,因此与传统的冷气微推力器相比,可大大提高推力器的比冲和推力。

A novel microplasma thruster using microhollow cathode discharge

The development and application of micro-satellites urgently needs new types of micro-thrusters.As an important classification of plasma discharges,microdischarge is favoured with considerable interest in the plasma field over the past decade.Microhollow cathode discharge (MHCD) is a kind of high pressure,non-equilibrium gas discharges.It can be operated with relatively low voltage (several hundreds volts) or input power(in the order of several hundreds of milliwatts) and it has an advantages of stable discharge under the high pressure.The MHCD device belongs to a kind of metal-dielectric-metal sandwich structure.Two electrodes (molybdenum or aluminium foils) are stacked on a dielectric layer (mica or alumina).The ports can be drilled through the sandwich with the hole diameter from dozen of microns to several hundreds microns.In combination of the extremely small dimensions and relative high and controllable gas temperature of the MHCD,it can be used as propulsion system of a newmicro electro-thermal thruster.The performance of the micro plasma thruster using MHCD,such as specific impulse and thrust,will be higher than that of the conventional cold gas micro-thruster,because the propellant gas is heated in the microdischarge plasma thruster and then expand through the micro-nozzle to produce the thrust.