Performance characterization of a helicon double layer thruster using direct thrust measurements

Abstract

Abstract. The performance of a Helicon Double Layer Thruster (HDLT) has been characterised using a pendulum type thrust stand and retarding field energy analyser. Data recorded for a fixed propellant flow rate of 16 sccm of krypton and fixed magnetic field topology show that the thrust generated increases linearly with increasing radio frequency input power over a range of 250 W to 650 W. Over the power range investigated thrust levels of approximately 1 to 2.8 mN were achieved. A maximum effective specific impulse of 280 s was determined using the thrust data. Ion energy distribution functions indicate that increasing power corresponds to improved plasma generation processes as general trends show increasing plasma and beam currents with increasing power.

Direct thrust measurements and modelling of a radio-frequency expanding plasma thruster

“…1,2,4,6 While prolific studies of the fundamental physics in such systems have been done, detailed experimental measurements of the thrust of such devices are only now beginning to be performed. 7,8 These thrust measurements are vital, as they allow almost all other electric propulsion figures of merit to be determined, 9 and thus, the performance of such systems to be assessed.Fruchtman has provided much of the theoretical groundwork for such plasma thrusters and has performed a number of detailed analyses in collisionless 10 and collisional regimes, 11 as well as investigating the effects of neutral depletion 10,11 and magnetic expansion. 12 In particular, in the absence of a magnetic field, the thrust has been predicted to be strongly linked to the maximum upstream electron pressure.…”

“…1,2,4,6 While prolific studies of the fundamental physics in such systems have been done, detailed experimental measurements of the thrust of such devices are only now beginning to be performed. 7,8 These thrust measurements are vital, as they allow almost all other electric propulsion figures of merit to be determined, 9 and thus, the performance of such systems to be assessed.…”

Experimental Identification of Thrust Components Imparted by an Electrodeless Helicon Plasma Thruster

“…(4) and Eq. (6), can be expressed as (8) where the first term of the right-hand side (rhs) is the Lorentz force due to the net azimuthal current j j i j e and the radial magnetic field B r . The electron and ion azimuthal current can be obtained from Eq.…”

“…The direct measurement of the thrust imparted by helicon thrusters operated at about 1 kW is presently being performed and the first results have shown the thrust of about 2-3 mN for 1 kW rf power 6,8) . In these experiments, it is reported that the static electron pressure inside the source is converted into the ion dynamic momentum through a spontaneously formed double layer or an ambipolar electric field.…”

Parametric analysis and design methods of Torsion thrust measurement system

“…For example, on condition of th ermal shock of high and low temperature, various operations and measurements are completed in a va cuum. Within the parametric analysis and design of torsion thrust measurement, thrusters' size, weight, maxi mum thrust, the calibration convenience of system parameters and the time required in thrust measure ment process, are all needed to taken into consideration [3] . The torsion system parameters include damping ratio, vibration frequency, torsional stiffness and moment of inertia, etc., and parameters of measured thrusters are as follows: (1) Size and weight of thrusters.…”