Measurement of Monodisperse Particle Charge in DC Plasma

Abstract

The experiments are carried out in the system consists of a monodisperse particle generator, a DC magnetized plasma generation system, and a charge measurement system. The plasma chamber is made of cross-shape Pyrex surrounded by magnetic bucket (composed of 12 permanent magnetic bar) to confine the plasma. DC magnetic field up to 9.6G is applied to the plasma zone by external magnetic coil. Previous work showed that the charging effect clearly increases with increasing the size of the particle and plasma density, as one expected. The result showed that Al2O3 particles in the size ranges of 30nm to 150nm where the number of charge varied from 20 to 45 elementary charges at the chamber pressure of 1.17 torr. If the magnetic field is applied at the chamber, Al2O3 particle of 50nm in diameter showed that the charge varied from ca. 15 elementary charges to 75 charges as the magnetic field changed from 0 to 9.6 G.