Kronhaus Igal, Laterza Matteo, Maor Yonatan
Aerospace Plasma Laboratory, Faculty of Aerospace Engineering, Technion - I.I.T., Technion City, 3200003 Haifa, Israel.
Rev Sci Instrum. 2017 Apr;88(4):043505. doi: 10.1063/1.4979706.
A new type of micropropulsion device for nanosatellite applications is presented-the inline-screw-feeding vacuum-arc thruster (ISF-VAT). This thruster couples a conventional "triggerless" ignition geometry with a feeding mechanism that maintains a steady state discharge performance. The feeding mechanism implements a screw action on a central cathode rod. At a predetermined rate, a complete and uniform erosion of the cathodes tip is obtained as well as "healing" of the insulator coating. The inline feeding of the cathode forces the arc to emerge on the tip of the cathode, flush with the exit plane of the anode. This enables the plasma plume to efficiently accelerate away from the thruster, eliminating the need for an additional ion acceleration stage. The ISF-VAT feeding mechanism is computer controlled and offers reliable operation of the thruster over a large number of pulses. Characterization of the ISF-VAT performance is presented, conducted on an experimental prototype in the Aerospace Plasma Laboratory, Technion. Measurement results of the mass flow rate, electrical parameters of the discharge, and thrust are presented. Using a Ti cathode at a discharge power of 3 W, a mass flow rate of ≈1.8×10 kg/s and a thrust level ≈ 7 μN were measured. More than 10 pulses were demonstrated in a single run, accumulating a total impulse of 0.2 Ns. The thruster prototype dimensions are 15 × 15 × 65 mm and are ≈ 60 g in mass.
本文介绍了一种用于纳米卫星应用的新型微推进装置——内联螺旋进料真空电弧推进器（ISF-VAT）。该推进器将传统的“无触发”点火几何结构与一种能维持稳态放电性能的进料机构相结合。进料机构对中心阴极棒实施螺旋作用。以预定速率，可实现阴极尖端的完全且均匀侵蚀以及绝缘涂层的“修复”。阴极的内联进料迫使电弧在阴极尖端出现，与阳极出口平面齐平。这使得等离子体羽流能够有效地从推进器加速离开，无需额外的离子加速阶段。ISF-VAT进料机构由计算机控制，并能在大量脉冲下使推进器可靠运行。文中展示了在以色列理工学院航空航天等离子体实验室的实验原型上对ISF-VAT性能的表征。给出了质量流率、放电电参数和推力的测量结果。在3W的放电功率下使用钛阴极时，测得质量流率约为(1.8×10)kg/s，推力水平约为7μN。单次运行展示了超过10个脉冲，累积总冲量为0.2Ns。推进器原型尺寸为15×15×65mm，质量约为60g。
