The Air Force Clustered Hall Thruster Program

Abstract

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High Throughput 600 Watt Hall Effect Thruster for Space Exploration

“…Performance and plume measurements showed no detrimental effects from clustering these thrusters. 9,30,31,32 Iodine fueled systems provide additional system and mission advantages. 33,34 At typical storage conditions, e.g.…”

Evaluation and Active Control of Clustered Hall Thruster Discharge Oscillations

“…The enormous vacuum chamber pumping rates required to run higher power Hall thrusters motivated the use of clustered configurations to allow for the testing of smaller individual thrusters 4 . Although, a cluster of thrusters totaling a high power level of 100kW will result in a lower thrust efficiency, a higher system dry mass and a shorter lifetime than a single (monolithic) larger thruster of equal power, the advantages of the clustered approach include: n-1 system redundancy, n step fully optimized throttlability, and cheaper system development 5 .…”

Rarefied Background Flow in a Vacuum Chamber

“…The goal of vacuum chambers is to maintain a low pressure. For example, in the experiments of testing a cluster of high power electric plasma thrusters inside vacuum chambers, [1][2][3] the backpressure was maintained at about 3 10 − - 4 10 − Pa. In such experiments, a high backpressure will distort the exhaust plume flow and affect the width of the ion energy distribution function through collisions between beam ions and neutral background particles.…”

“…In the experiments [1][2][3] , the backpressure of xenon is calculated using the ideal gas law P b =nkT w , where n is the xenon number density measured using an ionization gauge and w T is the chamber temperature. The ideal location to measure the background density is on the centerline of the chamber and between the pumps and the thrusters.…”