Izvorni znanstveni članak
The magnetron discharge as a source of H- ions
K. Prelec
; Brookhaven National Laboratory, Upton, New York and Instititute "Ruđer Bošković", Zagreb
Z. W. Šternberg
; Brookhaven National Laboratory, Upton, New York and Instititute "Ruđer Bošković", Zagreb
Sažetak
The energy distribution of fast hydrogen atoms formed by neutralization of positive ions and subsequent backscattering at the magnetron cathode is derived from the contours of Balmer lines emitted in the direction parallel to the electric field. The effects of inelastic collisions in the discharge on the distribution function thus obtained are considered. The effective yield of H- per backscattered H atom, a, is estimated from the calculated coefficients of secondary emission8) and from the energy distribution of atoms backscattered at the cathode; a is found to be ~ 0.5 for a cesiated molybdenum surface. It is shown that the attenuation of the flux of fast H- ions generated at the magnetron cathode is mainly due to slowing down of H- by charge exchange and destruction of slow H- by charge transfer and collisional detachment in the positive column. The thermal regime of magnetron cathodes and the rate of desorption of chemisorbed cesium are considered and a scaling law is derived which relates thermal load, discharge pulse duration and increase of cathode surface temperature.
Ključne riječi
Hrčak ID:
327890
URI
Datum izdavanja:
10.1.1977.
Posjeta: 83 *