Intra-atomic Electron-Electron Scattering in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">p</mml:mi></mml:math>-He Collisions (Thomas Process) Investigated by Cold Target Recoil Ion Momentum Spectroscopy

V. Mergel, R. Dörner, M. Achler, Kh. Khayyat, S. Lencinas, J. Euler, O. Jagutzki, S. Nüttgens, M. Unverzagt, L. Spielberger,

Physical Review Letters · 1997 · 82 citations · 19 references

Concepts

Abstract

We have performed a kinematically complete experiment for the transfer ionization reaction $0.15--1.4\mathrm{MeV}p+\mathrm{He}\ensuremath{\rightarrow}{\mathrm{H}}^{0}+{\mathrm{He}}^{2+}{+e}^{\ensuremath{-}}$ by measuring the three-dimensional momentum vector of the ${\mathrm{He}}^{2+}$ ion in coincidence with the scattering angle and the plane of the ${\mathrm{H}}^{0}$. In the measured fourfold differential cross section we can clearly distinguish between the independent two-step process of capture plus ionization and the correlated $e$- $e$ Thomas scattering. We find a ${v}_{P}^{\ensuremath{-}7.4\ifmmode\pm\else\textpm\fi{}1}$ scaling for the total cross section of the $e$- $e$ Thomas process.

References

19