RESEARCH ON THE BIPOLAR THRUSTOR.
Abstract
A 16-needle, bipolar thrustor producing 50 lbs has been run for two 50-hour life tests; one at a specific impulse of about 700 seconds and the other at a specific impulse of about 800 seconds, A floating collector was used continuously during each life test to determine overall beam neutrality which, during the majority of either run, was less than + or - 100 volts. NaI-glycerol (4700 ohm-cm at 25 C) was the positive fluid and SnCl4-glycerol (7200 ohm-cm at 25 C) was the negative fluid. The negative fluid was developed to eliminate the electrolytic generation of hydrogen gas bubbles in the negative needles. Before the bubbles were eliminated it was impossible to produce steady D.C. beams with high Q/M and high Isp. Additional improvement in performance was made when the needle-extractor capacity was reduced to eliminate the heavy arcing that became a problem when the high voltages (7 to 10 KV), needed to produce Isp's near 1000 sec., were applied. In order to determine the voltages and feed pressures necessary to produce beams within certain performance limits, parametric studies were made using a single needle-extractor set-up. Data defining the effect of temperature, feed pressure, and needle-extractor voltage on performance were taken. During the last life test, data from the 16-needle, bipolar thrustor consistently agreed with these parametric studies. Such consistency of performance is encouraging because it indicates colloid thrustors can now be reliably designed to meet the specific needs of a mission. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 20, 1967
- Accession Number
- AD0820862
Entities
People
- Philip W. Kidd
Organizations
- TRW Inc.