Isotope effect of H^-/D^- volume production in low-pressure H_2/D_2 plasmas : Measurement of VUV emissions and negative ion densities

Creators Fukumasa O.

Creators Mori S.

Creators Nakada N.

Creators Tauchi Y.

Creators Hamabe M.

Creators Tsumori K.

Creators Takeiri Y.

Isotope effect on H^-/D^- volume production is studied by measuring both VUV emission and negative ion density in the source. In a double plasma type source, under some discharge conditions, extracted D^- currents are nearly the same as H^- currents, although VUV emission intensity (corresponding to production of vibrationally excited molecules) in D_2 plasmas is slightly lower than that in H_2 plasmas. Considering the factor √<2> due to mass difference, D^- ion density in the extraction region of the source is higher than H^- ion density. In another experiment with a rectangular arc chamber, axial distributions of H^-/D^- ion densities in the source are measured directly using a laser photodetachment 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 D_2 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.

[ISSN]0863-1042

[NCID]AA10760174

https://doi.org/10.1002/ctpp.200410073

[isPartOf] [URI]http://www3.interscience.wiley.com/journal/117933212/grouphome/home.html