Isotope Effect of H−/D− Volume Production in Low-Pressure H2/D2 Plasmas — Negative Ion Densities versus Plasma Parameters

Isotope effect on H - /D - volume production is studied in a rectangular arc chamber. Axial distributions of H-/D- ion densities in the source are measured directly using a laser photodetach.ment method. Relationship between H - /D - production and plasma parameter control with using a magnetic filter (MF) is discussed. Furthermore, relative intensities of extracted negative ion currents are discussed compared with the negative ion densities in the source. Production and control of D2 plasmas are well realized with the MF including good combination between the filament position and field intensity of the MF. Extracted H - and D - currents depend directly on negative ion densities in the source.