Conditions for geomagnetically trapping sub-micron lunar ejecta between L = 1.2 and L = 3.1

Interplanetary particulate matter impacts the surface of the moon with velocities 10 km/sec. Craters are created during this collision and some resulting lunar ejecta with radii of one micron or less can have velocities relative to the lunar surface that are sufficient to escape the moon's gravitational sphere of influence. It has been shown that as much as 85% of these particles enter the magnetosphere during favorable orbital locations of the moon. Prior to this investigation, the factor which limited the equilibrium potential a particle would reach in space was the electrostatic breakup potential. An extensive analysis of field-emission effects on the potential of the particle has been conduced as a significant part of the work. The results of this effort show that the dominant factor in the determination of the equilibrium potential of micron-size particles in space is field emission. After determining the potential of the particles reaching the magnetosphere, the dynamics of these particles was studied. The most interesting region of the magnetosphere found during this investigation was the zone on the sunward side of the earth between L values of 1.2 and 3.1