Solar Arrays for Direct-Drive Electric Propulsion: Electron Collection at High Voltages
| Autor: | G. A. Jongeward, Thomas W. Kerslake, Todd Schneider, D. Snyder, Todd Peterson, Ioannis G. Mikellides |
|---|---|
| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Journal of Spacecraft and Rockets. 42:550-558 |
| ISSN: | 1533-6794 0022-4650 |
| Popis: | Solar array technologies that can empower electric thrusters in direct drive mode may provide significant mission benefits by reducing power processing, system complexity, weight, and cost over conventional systems. In direct-drive systems the solar arrays will operate at high voltages and must perform safely in the surrounding plasma environment, with minimal loss of performance due to parasitic current collection. For example, current state-of-the-art Hail effect thrusters in the kilowatt class require applied voltages of 300 V or higher. Results from experiments and modeling of electron current collection at high bias voltages (300-500 V) are presented. The experiments employed two sample solar array coupon technologies. A hollow cathode was used to emulate the induced environment around the solar arrays far from the Hall thruster and in nearby regions populated by charge-exchange plasma (10 1 2 -10 1 3 m - 3 and 0.5-1 eV). The measurements show that tens to hundreds of seconds are required before the collected current relaxes to a quasi-steady value. Comparisons with results from numerical calculations suggest that changes of the secondary electron yield properties of the dielectric materials may account for the observed current collection trends. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|