Charging and Acceleration of Microparticles

Development work on charging and acceleration of microparticles gives promise of a micrometeoroid simulator capable of producing velocities well into the meteoric range. Velocities up to 7 km/sec have been attained with highly charged micron‐size diamond particles with a 70‐kV accelerating voltage. Single particles electrodynamically contained in a high vacuum are charged positively by an ion current to give charge‐to‐mass ratios approaching 400 C/kg. Once charged, the particle is extracted from the containing field and accelerated by a high potential. Preliminary work on charging microparticles of other materials demonstrates the possibility of producing high charge‐to‐mass ratios on many substances by this technique.