Diagnostics for hot plasmas using hydrogen neutral beams

Technical Report · Wed Dec 01 04:00:00 EST 1982

DOI:https://doi.org/10.2172/6898261· OSTI ID:6898261

Goldston, R J

Beams of neutral hydrogen atoms have found a number of uses in the diagnosis of hot plasmas. In the most straightforward application, neutral beams have been used to determine plasma line density, based on simple attenuation measurements. This technique has been applied most intensively recently to the study of beam-injected mirror plasmas. Neutral beams have also now been used in a number of tokamaks to supply a local increase of the neutral atom target density for charge exchange. By directing a time-modulated neutral beam across the sight-line of a charge-exchange analyzer, and measuring the modulated neutral particle efflux from the plasma, local measurements of the ion energy distribution function can be made. If a modulated diagnostic neutral beam is directed across the sight-line of an ultra-violet spectrometer, one can also make measurements of the local densities and possibly velocity distributions of fully stripped impurities. The fast hydrogen neutrals charge exchange with fully stripped impurities in the plasma, leaving the impurities in excited hydrogen-like states. In their prompt radiative decay the impurity ions emit characteristic uv lines, which can be detected easily.

• Research Organization: Princeton Univ., NJ (USA). Plasma Physics Lab.
• DOE Contract Number: AC02-76CH03073
• OSTI ID: 6898261
• Report Number(s): PPPL-1952; ON: DE83003904
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700102* -- Fusion Energy-- Plasma Research-- Diagnostics
ATOMIC BEAMS
BEAM INJECTION
BEAMS
CHARGE EXCHANGE
CLOSED PLASMA DEVICES
ELECTROMAGNETIC RADIATION
IMPURITIES
NEUTRAL ATOM BEAM INJECTION
PLASMA DIAGNOSTICS
RADIATIONS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
ULTRAVIOLET RADIATION