High-flux source of low-energy neutral beams using reflection of ions from metals

Journal Article · Sat Oct 31 23:00:00 EST 1992 · Review of Scientific Instruments; (United States)

DOI:https://doi.org/10.1063/1.1143440· OSTI ID:7201369

Cuthbertson, J W; Motley, R W; Langer, W D ^[1]

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1. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

Reflection of low-energy ({lt}100 eV) ions from surfaces can be applied as a method of producing high-flux beams of low-energy neutral particles, and is an important effect in several areas of plasma technology, such as in the edge region of fusion devices. We have developed a beam source based on acceleration and reflection of ions from a magnetically confined coaxial rf plasma source. The beam provides a large enough flux (over 4 A ion current, or 5{times}10{sup 16} atoms/cm{sup 2} s at 10-cm range) to allow the energy distribution of the reflected neutrals to be measured despite the inefficiency of detection, by means of an electrostatic cylindrical mirror analyzer coupled with a quadrupole mass spectrometer. Energy distributions have been measured for oxygen, nitrogen, and inert gas ions incident with from 15 to 70 eV reflected from amorphous metal surfaces of several compositions. For ions of lighter atomic mass than the reflecting metal, reflected beams have peaked energy distributions; beams with the peak at 4--32 eV have been measured. The energy and mass dependences of the energy distributions as well as measurements of absolute flux, and angular distribution and divergence are reported. Applications of the neutral beams produced are described.

• OSTI ID: 7201369
• Journal Information: Review of Scientific Instruments; (United States), Journal Name: Review of Scientific Instruments; (United States) Vol. 63:11; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

661220* -- Particle Beam Production & Handling
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700460 -- Fusion Technology-- Heating & Fueling Systems
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAM ANALYZERS
DESIGN
ELECTROSTATIC ANALYZERS
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 10-100
Fu
Fuels-- (1992)
METALS
NEUTRAL BEAM SOURCES
NITROGEN
NONMETALS
OXYGEN
REFLECTION
Ta
Targets-- (1992-)