CONDENSATION COLLOIDAL ION SOURCE.
Summary technical rept. for 1 Jun 62-1 Jun 63.
ION PHYSICS CORP BURLINGTON MASS
Pagination or Media Count:
The report describes the experimental and analytical efforts on the evaluation of the controlled-growth, condensation colloidal ion source concept as a means of producing propellant particles for use in an electrostatic ion engine. An improved concept is presented which depends on convection rather than radiation for cooling the particles and assumes the presence of electrons in the nozzle. These factors relieve space charge restrictions but necessitate removal of electrons downstream from the throat and increase the requirements for collisions. Design considerations to provide the necessary conditions are discussed and were incorporated in the construction of a controlled-growth colloidal ion engine which performed well in thrust tests. Theoretical analyses show that sodium or lithium could give the performance required of a colloidal ion engine if neutral nucleation is insignificant. Detailed experimental studies of nozzles and ionizers are described which indicate that the skimmer nozzle and a free arc ionizer can best fulfill the requirements of the colloidal ion source. Author