We have determined absolute cross sections for electron capture into the quasi-degenerate 4l states of He+ produced in collisions of He2+ on atomic hydrogen. The cross sections have been deduced by deconvoluting spatial HeII(n = 4 --> n = 3) emission profiles. The measurements have been performed in the impact energy range of 2 - 130 keV/amu. The results are compared with theory. In addition we discuss the relevance of these cross sections to alpha-particle diagnostics in fusion plasmas. At the JET tokamak the HeII(n = 4 --> n = 3) emission can be used to determine related quantities like ion temperature, plasma rotation and local alpha-particle densities.
|Tijdschrift||Zeitschrift für Physik. D: Atoms Molecules and Clusters|
|Status||Published - 1991|
|Evenement||5TH INTERNATIONAL CONF ON THE ATOMIC PHYSICS OF HIGHLY CHARGED IONS - , Germany|
Duur: 10-sep-1990 → 14-sep-1990