Experimental Data on Pumping of Mercury Ion Beams by Liquid-nitrogen-cooled Condensers PDF Download

Author: Edward A. Maslowski
Publisher:
ISBN:
Category : Mercury
Languages : en
Pages : 20

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Book Description
A program was conducted to evaluate the performance of liquid-nitrogen-cooled condensers in pumping the exhaust of mercury ion thrustors. Tests were conducted with two different condensers. One of the condensers was a smooth cylinder having a total surface area of 3. 8 square meters, and the other condenser was of honeycomb type of construction and had a total surface area of 62. 9 square meters. Two targets, having apex angles of 320 and 1480, respectively, were used with each condenser. Ion beam current ranged from 10 to 200 milliamperes and accelerating potential from 2. 0 to 6. 0 kilovolts. The results were evaluated on the basis of a performance factor F̂ which is a function of the condenser accommodation and sticking coefficients. A mean value of F̂ of 0. 75 was determined in this study. A visual observation of mercury distribution patterns showed that the ratio of effective pumping area to actual geometric area was 0. 4 for the smooth condenser and 0. 1 for the honeycomb condenser. This study showed no significant difference in the effect of the two targets.