INVESTIGATIONS OF COLLISION DYNAMICS AND EXCITATION CROSS SECTIONS FOR He+
(1snp) 1P0 STATES (n=2-5) BY INTERMEDIATE AND HIGH VELOCITY ELECTRON,
PROTON, AND MOLECULAR ION (H2+ AND H3+) IMPACT USING EUV SPECTROMETRY


H. Merabet*, M. Bailey*, R. Bruch*, S. Bliman$, A. Siems#, A. G.
Trigueiros#, D. V. Fursa@ and I. Bray@


*Department of Physics, University of Nevada Reno, Reno NV 89557 USA
$Department de Physique, Universiti de Marne la Vallie, 93l66 Noisy
LeGrand, France
#Quantum Electronic Department, Physics Institute- UNICAMP, Campinas,
Brazil
 @Electronic Structure of Materials Centre, The Flinders, University of
South Australia,
GPO Box 2100, Adelaise 5001, Australia


A comprehensive study of helium excitation cross sections in the extreme
ultraviolet (EUV) range following electron, and H+,H2+, and H3+ ion impact
is given for He (1snp) 1Po states with n=2-5. These measurements extend
over a large velocity range from 1.4 to 8.5 a.u. and represent the most
complete data set obtained so far in the EUV. Furthermore, a comparison of
all experimental and theoretical data including our new close convergent
coupling calculations for the excitation of He (1snp) 1Po by e- + He
collisions is provided.