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Proton beams at 0.3, 0.5 and 1 keV energies were injected onto a Mo surface at shallow incidence angle, and the angle- and energy-resolved intensity distributions of reflected negative/positive ions were measured. The negative to positive intensity ratio increased as the incident angle and the reflected angle became shallower and the incident energy became lower. A numerical simulation calculation, Atomic Collision in Amorphous Target (ACAT), has been carried out to get the angular distribution of total reflection particle flux. Experimentally measured angular distributions of reflected H- ion intensity showed maxima at smaller angles than the calculated results, indicating that the negative ion formation has a maximum at v⊥ of 0.03 - 0.04 atomic unit.

As one of candidate materials for a low work function plasma grid, a new inorganic material, C12A7 electride having the low work function and high electrical conductance, was studied experimentally. The photoelectric current from the material under irradiations with 325 nm He-Cd laser and 405 nm, 450 nm, 532 nm diode lasers was measured. The measured work function was less than 2.7 eV. Exposure to the C12A7 electride to an atomic hydrogen (H0) flux has produced electric current corresponding to negative hydrogen ion (H-) current from the surface. Similar characteristics were obtained for a low-work-function bi-alkali material covered molybdenum surface (∼2.3 eV). Nearly the same negative current signals were observed under the same exposure condition of atomic hydrogen flux.

(1) The progress of the reaction between waste soda and hydrogen sulphide gas was determined by acidimetric method with phenolphthalein as the indicator or by the specific gravity of the solution.(2) When waste soda was satulated with hydrogen sulphide gas γ cellulose remained in solution. β cellulose remained in solution when waste soda changed into Na2S liquor and 47% of β cellulose precipitated when waste soda changed into NaSH liquor.(3) By mixing equal quantities of waste soda and hydrosulphide liquor, sulphide liquor containing 0.6% of β cellulose and 0.24% of γ cellulose was obtained. Apart from the point of hemicellulose, the liquor had about the same composition as that obtained by dissolving commercial Na2S, and so the liquor may be used for desulphurisation of sulphur yarn.