Sputtering of negative hydrogen ions from molybdenum

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:5645780

Greer, J A

The production of negative hydrogen ions sputtered from a low work function molybdenum surface was investigated. Hydrogen and cesium are continuously adsorbed onto a polycrystalline molybdenum target in high vacuum. The hydrogen is then sputtered as a negative ion from this cathode by energetic cesium ions. Electrons and Mo/sup -/ ions are sputtered as well. The parameter of interest is called the negative H/sup -/ ion yield and is defined as the number of H/sup -/ ions sputtered per incident cesium ion. Hydrogen, molybdenum, as well as electron yields sputtered within a 14/sup 0/ acceptance half-angle were obtained for incident cesium ion energies ranging from 150 eV up to 900 eV. The work function of the Mo surface was monitored during the sputtering process. The maximum yields were obtained with a minimum work function surface of 1.60 eV. The maximum H/sup -/ ion yield was 0.53 obtained at 750 eV. The maximum Mo/sup -/ and e/sup -/ yields were 0.07 and 0.15 obtained at 900 eV and 625 eV respectively. The negative ion yield can be equated to the product of a neutral atom yield times a velocity dependent parameter ..beta... This parameter is the probability of formation of a negative ion.

• Research Organization: Stevens Inst. of Tech., Hoboken, NJ (USA)
• OSTI ID: 5645780
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ANIONS
CESIUM IONS
CHARGED PARTICLES
COLLISIONS
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 100-1000
FERMIONS
FUNCTIONS
HYDROGEN IONS
HYDROGEN IONS 1 MINUS
IONS
LEPTONS
METALS
MOLYBDENUM
MOLYBDENUM IONS
PRODUCTION MECHANISMS
SPUTTERING
TRANSITION ELEMENTS
WORK FUNCTIONS