AN基推进剂在脉冲激光辐照下的电场加速特性

Electric Acceleration Characteristics of AN-Based Propellant under Pulsed Laser Irradiation

关键词:  等离子体推力器  推进剂  推力性能  电弧放电  激光推进

Key words:  Plasma thruster  Propellant  Thrust performance  Arc discharge  Laser propulsion

摘要:

为了研究加速电极结构对激光脉冲等离子体推力器推力性能的影响，分别用三种构型的加速电极对推力器的放电性能进行了试验。同时，为了提高推力器的推力性能，采用AN基推进剂替代传统PTFE推进剂进行了试验，并分析对比了两种推进剂的推力性能。通过电流探针、光电传感器以及微冲量测试平台等装置对推进剂进行了相应测试。结果表明：加速电极长度与宽度的增加均不利于引发电弧放电，导致推力器的放电延迟时间延长；AN基推进剂相比于PTFE推进剂具有更高的等离子体峰值电流以及更短的放电延迟时间；随着放电电压由0V升高至1500V，AN基推进剂的比冲由295.10s升高至738.47s，而PTFE推进剂的比冲由114.40s升高至499.40s。AN基推进剂自身所含的化学能提高了推进剂的微冲量，但同时也增加了推进剂的质量消耗。尽管如此，相比于PTFE推进剂，AN基推进剂仍具有最高的比冲以及更优的推力性能。

Abstract:

Acceleration electrodes with three types were presented to test the discharge performance of the laser-pulsed plasma thruster （LPPT）， aiming to investigate the effects of electrode geometry on thrust performance. Furthermore， AN-based propellant was designed as substitute for ordinary PTFE propellant to enhance the thrust performance of the LPPT， and the thrust performance of the two propellants was compared. The performance of the propellant was analyzed by current probe， photoelectric sensor and a micro-impulse test bench. The results suggest that increasing length and width of the electrodes are not conducive to arc discharge， which leads to an increase in discharge delay time. AN-based propellant has higher plasma peak current and shorter discharge delay time compared to PTFE propellant. As the discharging voltage increases from 0V to 1500V， the specific impulse of the AN-based propellant increases from 295.10s to 738.47s， while the PTFE propellant increases from 114.40s to 499.40s. The chemical energy contained in the AN-based propellant improves the impulse bit， but it also increases the mass consumption of the propellant. Nevertheless， AN-based propellant still has the highest specific impulse and better thrust performance compared to PTFE propellant.