Ionization and autoionization in small impact parameter H + + He and in high energy Ne10+ + He collisions

doi:10.1016/0168-583X(89)90951-8

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms

Volumes 40–41, Part 1, 2 April 1989, Pages 178-183

https://doi.org/10.1016/0168-583X(89)90951-8 Get rights and content

Abstract

Absolute doubly-differential electron emission yields were measured as a function of angle and energy of ejection for projectile scattering angles of 0.3° to 3° in 30-, 100- and 300-keV proton-helium collisions. The secondary electron spectra correspond to impact parameters which are small compared to the He(1s²) orbital radius. The experimental data clearly favor quantum mechanical and classical highest order theories for the description of the ionization process. Doubly-differential cross sections measured for 5 MeV/amu Ne¹⁰⁺ + He collisions also show higher order effects which may be clearly distinguished from those at low impact energies. The coincidence data for H⁺ + He exhibit a dominant line structure originating from the decay of the doubly excited 2s²¹S state. The corresponding line intensity shows an angular anisotropy which is interpreted as a Fano interference between the amplitudes of autoionization and direct ionization.

References (28)

V. Montemayor and G. Schiwietz, submitted to J. Phys....
P.W. Arcuni et al.
Phys. Rev.
(1987)
V.V. Afrosimov et al.
Zh. Eksp. Teor. Fiz.
(1974)
Sov. Phys.-JETP
(1975)
R.D. Du Bois
Phys. Rev. Lett.
(1984)
M.B. Shaw et al.
J. Phys.
(1985)
C.E. Kyatt et al.
Phys. Rev.
(1963)
M.E. Rudd et al.
Phys. Rev.
(1963)
L.H. Toburen et al.
Phys. REv.
(1972)
S.T. Manson et al.
Phys. Rev.
(1975)
S.T. Manson, private...G. Schiwietz
Phys. Rev.
(1988)

G. Schiwietz, B. Skogvall, J. Tanis and D. Schneider, Phys. Rev. A38, in...

G. Schiwietz et al.

Phys. Rev.

(1987)

W. Fritsch, private communication...

T. Mukoyama et al.

Phys. Rev.

(1985)

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Citation Excerpt :
At large impact parameters, small energy transfer and weak ion–solid interaction are dominant, and a single oscillator strength will underestimate the energy loss at asymptotically large impact parameters [23]. For strong ion–solid interaction under small impact parameters conditions, using empirical parameters charge density and oscillator strengths, they observed large electronic energy loss accompanied by strong interactions,23 which is in good agreement with the experimental results [24]. A dozen years ago, time-dependent ab initio calculations successfully solved the ESP (energy lost per unit length) of low-speed ion traversing process, resulting in the well agreement with the experiment values [7,25].
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^∗: On leave from the University of Lund, Lund, Sweden.

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Section I. Atomic physics and related phenomenaIonization and autoionization in small impact parameter H + + He and in high energy Ne10+ + He collisions

Abstract

Phys. Rev.

Zh. Eksp. Teor. Fiz.

Sov. Phys.-JETP

Phys. Rev. Lett.

J. Phys.

Phys. Rev.

Phys. Rev.

Phys. REv.

Phys. Rev.

Phys. Rev.

Phys. Rev.

Phys. Rev.

Section I. Atomic physics and related phenomena
Ionization and autoionization in small impact parameter H ⁺ + He and in high energy Ne¹⁰⁺ + He collisions