Electron capture and excitation in He²⁺-Na collisions

Abstract

State-selective charge transfer and target excitation in collisions of He2+ ions with Na has been studied by means of far ultraviolet and visible light spectroscopy. Generally, the experimental results confirm the theoretical predictions by Shingal et al. (1987) for electron capture and for the dominant excitation channel, Na(3p). However in the lower half of the impact energy range studied, 2-9 keV amu-1, discrepancies in energy dependence and absolute magnitude (up to a factor of approximately 6) are found for the Na(4p) and Na(4d) excitation channels.

Spin-polarized electron capture for the Na+3He2+system at aTanaka1, Shimakura2, Ohshima3 et al. 1994Phys. Rev. A9070View full textAdd to dashboardCite

“…Though these values are larger than the direct observation [1,28] by about 2 -3 times, the observed behavior in Fig. 3(a) is well reproduced by the present calculation.…”

“…III. In order to examine the validity of the present theoretical calculation, we compared the calculated capture cross sections with the observed values for the He+Na system [1,28]. In Fig.…”

“…Data indicated by the open circles are observed partial cross sections feeding to n =3 and 4 states in 'He+ and are referred from Ref. [28]. Data indicated by the open squares are the observed partial capture cross section feeding to n =3 states in 'He+.…”

“…ed by the open and closed circles are, respectively, partial capture cross sections feeding to the He+ states with n = 3,4 and n = 3 states, which were obtained by observing decaying photons [28]. The solid curve is the theoretical capture cross sections summed over states with n =1-n =4.…”

“…The result obviously showed no evidence for asymmetry, from which the observed asymmetries for He+ are really due to the nuclear effect. From this result, one can deduce the observed polarization transfer coefficient Pz" defined by P, ( 15) PT-PNa (28) The measurement of Pz at impact energies other than 6.67 keV/amu is not straightforward because the analyzing power A defined by Eq. (25) might be dependent on impact energy.…”