Design and Testing of a Supercritical Helium Beamline Cryopump for a Neutral Particle Beam in Space
As part of the BEAR Project (Beam Experiments Aboard a Rocket), being conducted by the Los Alamos National Laboratory and sponsored by the SDIO, the first ever flight qualified beamline cryopump for a neutral particle beam in space, has been designed, fabricated and tested.
The BEAR payload consists primarily of a neutral particle beam accelerator whose injector produces a beam of negatively charged hydrogen ions that are accelerated by a radio frequency quadrupole and subsequently neutralized in a Xenon gas cell neutralizer. The cryopump was designed to pump any Xenon gas backstreaming from the neutralizer and any condensable gases outgassing from the accelerator components. It has a useful volume of 5 liters of supercritical helium and maintains the cryopump condensation surface below 22 Kelvin for over 5 hours, after isolating the flight dewar from the ground support equipment system.
This paper describes the technical approach, thermal and structural analyses used in the design of the flight dewar and related ground support equipment, as well as, the results of the thermal and environmental testing for shock (in excess of 27g’s), random vibration (9g’s rms) and cryogen hold time.
KeywordsHelium Epoxy Sine Xenon Emissivity
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