Design and test of porous-tungsten mercury vaporizers.

Future use of large size Kaufman thrusters and thruster arrays will impose new design requirements for porous plug type vaporizers. Larger flow rate coupled with smaller pores to prevent liquid intrusion will be desired. This paper presents the results of testing samples of porous tungsten for flow rate, liquid intrusion pressure level, and mechanical strength. Nitrogen gas was used in addition to mercury flow for approximate calibration. Liquid intrusion pressure levels will require that flight thruster systems with long feed lines have some way (a valve) to restrict dynamic line pressures during launch.