Europhys. Lett.
Volume 63, Number 1, July 2003
Page(s) 49 - 55
Section Physics of gases, plasmas and electric discharges
Published online 01 June 2003
DOI: 10.1209/epl/i2003-00476-x
Europhys. Lett., 63 (1) , pp. 49-55 (2003)

Results of an experiment relating apparent Doppler ion temperatures with non-thermal velocities in hot-fusion plasmas

K. J. McCarthy, B. Zurro, R. Balbín, A. Baciero, J. Herranz and I. Pastor

Laboratorio Nacional de Fusión, Asociación Euratom-CIEMAT - E-28040 Madrid, Spain

(Received 3 April 2003; accepted 5 May 2003)

We present the results of an experiment carried out in the core of a hot magnetically confined plasma to substantiate a claimed relationship between apparent ion temperatures and non-thermal velocities. For this, the heaviest ions were injected into the plasma by laser ablation and localised ion temperatures were obtained from Doppler line-widths and energy spectra of escaped charge-exchange neutrals. Strong collisional coupling between majority ( $\chem{H^+}$) and impurity ions ensures that these should be well thermalised. However, the linear dependence found between apparent ion temperature and mass ( $\chem{H}$, $\chem{O}$, $\chem{Si}$, $\chem{Fe}$) permits one to relate apparent Doppler ion temperatures to non-thermal velocities. The implications for the physics and diagnosis of thermonuclear plasmas are addressed.

52.25.Vy - Impurities in plasmas.
52.35.Ra - Plasma turbulence.
52.55.Hc - Stellarators, torsatrons, heliacs, bumpy tori, and other toroidal confinement devices.

© EDP Sciences 2003