Negative-hydrogen-ion production by backscattering from alkali-metal targets
Measurements have been made of the total backscattered D/sup -/ and H/sup -/ yields from Cs, Rb, K, Na and Li surfaces bombarded with D/sub 2//sup +/, D/sub 3//sup +/, H/sub 2//sup +/ and H/sub 3//sup +/ in the energy range 0.15 to 4 keV/nucleus. All measurements were made at a background pressure less than 10/sup -9/ Torr and the alkali-metal surfaces were evaporated onto a substrate in situ to minimize contamination of surfaces. For each target, the D/sup -/ and H/sup -/ yields exhibited maxima (as high as 8% per incident deuteron or proton for Cs); the maxima occurred at incident energies between 300 and 1000 eV/nucleus and always occurred at a lower incident energy for H than for D for a given target. Both the H/sup -/ and D/sup -/ yields decreased, at any measured energy, in going from Cs to Li in the order given above. Measurements of the H/sup -/ yield were also made for H/sub 3//sup +/ bombarding a W substrate, as a function of the work function of the target, as Li was deposited on the W. The work function of the target showed a minimum as the Li coverage was increased and the H/sup -/ yield showed a corresponding maximum which was almost two orders of magnitude higher than the H/sup -/ yield for a thick Li target.
- Research Organization:
- California Univ., Berkeley (USA). Lawrence Berkeley Lab.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5653633
- Report Number(s):
- LBL-9992; CONF-791057-2; TRN: 80-004794
- Resource Relation:
- Conference: Workshop on hydrogen recycling, Livermore, CA, USA, 17 Oct 1979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
CESIUM
CHARGE EXCHANGE
ION COLLISIONS
DEUTERIUM IONS
BACKSCATTERING
HYDROGEN IONS 2 PLUS
HYDROGEN IONS 3 PLUS
LITHIUM
POTASSIUM
RUBIDIUM
SODIUM
TUNGSTEN
KEV RANGE 100-1000
ALKALI METALS
CATIONS
CHARGED PARTICLES
COLLISIONS
ELEMENTS
ENERGY RANGE
HYDROGEN IONS
IONS
KEV RANGE
METALS
MOLECULAR IONS
REFRACTORY METALS
SCATTERING
TRANSITION ELEMENTS
640301* - Atomic
Molecular & Chemical Physics- Beams & their Reactions