Koichi Ogura

Removal of the plasma contained in an atomic beam produced by electron beam heating

Removal of the plasma contained in a gadolinium atomic beam produced by electron beam heating was investigated. A positive or negative electric potential was applied to the plasma removal electrodes which were a pair of parallel electrodes put along the atomic beam. When a positive potential was applied to the plasma removal electrodes, the plasma could not be removed at high evaporation rates. On the other hand, the plasma could be removed by applying a high negative potential to both removal electrodes, even at high evaporation rates. The potentials applied to the electrodes required to remove the plasma were estimated using the model that a plasma at ground potential flows with the atomic beam; ions are extracted from the plasma by negatively biased removal electrodes. The estimated potentials required to remove the plasma agreed well with experimental values.

NEW METHOD FOR THE MEASUREMENT OF GADOLINIUM ATOMIC BEAM VELOCITY USING LANGMUIR PROBES

The velocity of a gadolinium atomic beam produced by electron beam heating was found to range from 700 to 1000 m/s by measuring the drift velocity of the plasma, which is produced by ionizing atoms in the atomic beam with pulsed dye lasers and using Langmuir probes. The measured atomic beam velocity spread agrees with that determined by the microbalance method.