微阴极电弧推力器放电特性试验研究

Experimental Research on Discharge Characteristics of Micro Cathode Arc Thruster

微阴极电弧推力器(μCAT)具有体积小、重量轻、功耗低、比冲高等优点,使其逐渐在越来越多的微纳卫星推进系统中被采用。目前,寿命是制约μCAT走向工程化应用的关键因素,而μCAT放电特性决定着其工作寿命及可靠性,因此对其放电特性开展研究,对于μCAT的设计具有重要意义。本文搭建了能够自动采集放电数据和记录点火次数的μCAT寿命试验系统。对其放电特性数据进行了分析,发现基于击穿电压和峰值电流的寿命变化规律可以分为起始段、稳定段、失效段等三个阶段,并建立了相应的数学模型,提出了当峰值电流下降到初始峰值电流的80%时μCAT失效的判据。

Micro Cathode Arc Thruster(μCAT)has the advantages of small size,light weight,low power consumption and high specific impulse.It is employed in a growing number of propulsion system of micro-nano satellites.At present,lifetime is the key factor restricting the engineering application ofμCAT.The discharge characteristics ofμCAT determine its working life and reliability,therefore the research on discharge characteristics is of great significance to the design ofμCAT.AμCAT lifetime test system is built to collect discharge data and record the number of ignitions automatically.Analysis of the discharge characteristic data shows that the lifetime based on breakdown voltage and peak current can be divided into three stages:initial stage,stable stage and failure stage.Corresponding mathematical models are established,and the criterion ofμCAT failure when the peak current drops to 80%of the initial value is proposed.