The interaction of fast alpha particles with pellet ablation clouds

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.872097· OSTI ID:474653

McChesney, J M; Parks, P B; Fisher, R K; Olson, R E ^[1]

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1. General Atomics, San Diego, California 92186-5608 (United States)

The energy spectra of energetic confined alpha particles are being measured using the pellet charge exchange method [R. K. Fisher, J. S. Leffler, A. M. Howald, and P. B. Parks, Fusion Technol. {bold 13}, 536 (1988)]. The technique uses the dense ablation cloud surrounding an injected impurity pellet to neutralize a fraction of the incident alpha particles, allowing them to escape from the plasma where their energy spectrum can be measured using a neutral particle analyzer. The signal calculations given in the above-mentioned reference disregarded the effects of the alpha particles` helical Larmor orbits, which causes the alphas to make multiple passes through the cloud. Other effects such as electron ionization by plasma and ablation cloud electrons and the effect of the charge state composition of the cloud, were also neglected. This report considers these issues, reformulates the signal level calculation, and uses a Monte-Carlo approach to calculate the neutralization fractions. The possible effects of energy loss and pitch angle scattering of the alphas are also considered. {copyright} {ital 1997 American Institute of Physics.}

• DOE Contract Number: AC02-83ER53153; FG03-92ER54150
• OSTI ID: 474653
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 4; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABLATION
ALPHA PARTICLES
CHARGE EXCHANGE
COLLISIONS
ENERGY LOSSES
ENERGY SPECTRA
MONTE CARLO METHOD
PELLETS
PLASMA CONFINEMENT
PLASMA DIAGNOSTICS
PLASMA IMPURITIES
THERMONUCLEAR IGNITION
THERMONUCLEAR REACTORS
WALL EFFECTS
plasma collision processes
plasma toroidal confinement
plasma-wall interactions