低功率肼推进剂电弧加热推力器（Arcjet）在国际上已有较成熟应用。由于
受小卫星的质量与可提供电功率等因素的制约，近年来 100W 级的小功率 Arcjet
得到了广泛的关注。氨易于液化、密度高、携带方便，是一种有良好应用前景的
推进剂。本论文工作采用实验室自行研制的小功率电弧推力器， 以氨为推进剂，
实现了电弧推力器的长时间稳定运行， 对推力器的运行参数与性能的关联进行了
测量和分析，并分析了喷管内放电状态对推力器性能的影响。
本研究的实验在已有的真空实验室平台上进行，真空腔直径 1 m，长 1.4 m，
真空泵组极限排气量 3500 L/s， 极限真空 10-4 Pa。实验条件范围为弧电流 120
mA～260 mA，气流量 200 mL/min～600 mL/min。 电弧推力器喷管的喉道直径 0.3
mm、喉道长度 0.5 mm，改变扩张比和阴极尖到喉道的间距，对电弧推力器进行
了性能测试。采用测量羽流冲击力的方式， 得到推力器在不同工况条件下的推力
数据，结合采集的弧电流、弧电压及气流量等工作参数， 推算出推力器的比冲和
推力效率等性能参数。采用铜镜反射和 ICCD 拍照相结合的方法，对推力器喷管
内的放电状态进行拍摄。
研究结果表明，在小功率氨电弧推力器运行的近 10000 s 时间内，性能稳定。
随着输入电功率的增加，喷管略有红热，肉眼几乎观测不到羽流。 推力器产生的
推力随气流量的增加而增大；在相同气流量条件下，输入功率越大，比冲越高。
在本研究的实验参数范围内， 电弧推力器比冲在 200 s～350 s 之间； 推力效率的
总趋势是随比功率的增大而降低；在本实验参数范围内， 当比功率相同时，推力
效率随气流量的增加而增加。在输入功率 60 W～95 W、气流量 300 mL/min～600
mL/min 的条件下， 推力器 A（扩张比 300、阴极尖与喉道间距 1.7 mm） 的推力
效率介于 13.5%～43.6%之间。 压缩段压力随气流量的增加而增大，弧电流变化
对压缩段压力的影响较小。推力器呈下降的伏安特性，弧电压变化范围在 400 V～
600 V 之间，远高于 1 kW 级氨电弧加热推力器 100 V 量级的电压值。在实验参
数范围内，放电电弧通过喉道，弧根均匀地周向贴附于阳极喷管扩张段的内壁面。

Low-power arcjet thrusters less than 100 W-class have attracted broad attention in
recent years for small satellites application, due to the limits of the weight and available
electric power on board. There is significantly reduced toxicity of ammonia compared
to hydrazine propellant. And ammonia has a great advantage in storability and
portability than gas type propellants. In the present work, experiments had been
conducted to investigate the performance of a low-power arcjet thruster designed by
the laboratory with ammonia as the propellant. The thruster could stably operate
continuously, and the thruster performance was discussed related to the working
condition.
The performance of the ammonia arcjet thruster was studied experimentally, in a
vacuum chamber of 1 m diameter and 1.4 m length with a pumping system capable of
3500 L/s. The extreme vacuum of the chamber can reach 10-4 Pa. The arc current was
changed from 120 mA to 260 mA, and gas flow rate varied from 200 mL/min to 600
mL/min. The thruster nozzles have the same throat size of 0.3 mm diameter and 0.5 mm
length but different expansion ratios and the distance from cathode tip to the throat. The
thrust generated by the low-power arcjet was measured by indirect method. The specific
impulse and thrust efficiency were derived from the operating parameter including arc
current, arc voltage and gas flow rate, and the measured thrust. The discharge condition
in the nozzle of the arcjet thruster was observed using a copper mirror and recorded by
an ICCD camera.
The experiment results indicated that the ammonia arcjet thruster could operate
stably up to nearly ten thousand seconds. The nozzle was slightly red-hot with
increasing input power, and the jet plume could hardly be observed. In this study, the
thrust produced by the thruster increased as the increasing of gas flow rate in the range
of 200 mL/min～600 mL/min. At the same gas flow rate, the higher the electrical input
power is, the higher the specific impulse is, ranging from 200 s to 350 s. The thrust
efficiency increased with the decreasing specific power and also with the increasing gas
flow rate. For example, thrust efficiency of the thruster, with the anode-cathode distance
1.7 mm and expansion ratio 300, ranged from 13.5% to 43.6% at the electrical input
power of 60 W～95 W, and the gas flow rate of 300 mL/min～600 mL/min. The
thruster had a reduced volt-ampere characteristic, with the voltage ranging from around
600 V to 400 V, which is much higher than the voltage of the 1 kW class ammonia arcjet
thruster. Furthermore, it is found that the arc volume passes through the constrictor and
that the arc-root is circumferentially attached to the expansion section of the anode
nozzle.