Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Direct and resonant double photoionization: from atoms to solids
- 2 The application of propagating exterior complex scaling to atomic collisions
- 3 Fragmentation of molecular-ion beams in intense ultrashort laser pulses
- 4 Atoms with one and two active electrons in strong laser fields
- 5 Experimental aspects of ionization studies by positron and positronium impact
- 6 (e,2e) spectroscopy using fragmentation processes
- 7 A coupled pseudostate approach to the calculation of ion–atom fragmentation processes
- 8 Electron impact ionization using (e,2e) coincidence techniques from threshold to intermediate energies
- 9 (e,2e) processes on atomic inner shells
- 10 Spin-resolved atomic (e,2e) processes
- Index
- References
10 - Spin-resolved atomic (e,2e) processes
Published online by Cambridge University Press: 05 January 2013
- Frontmatter
- Contents
- List of contributors
- Preface
- 1 Direct and resonant double photoionization: from atoms to solids
- 2 The application of propagating exterior complex scaling to atomic collisions
- 3 Fragmentation of molecular-ion beams in intense ultrashort laser pulses
- 4 Atoms with one and two active electrons in strong laser fields
- 5 Experimental aspects of ionization studies by positron and positronium impact
- 6 (e,2e) spectroscopy using fragmentation processes
- 7 A coupled pseudostate approach to the calculation of ion–atom fragmentation processes
- 8 Electron impact ionization using (e,2e) coincidence techniques from threshold to intermediate energies
- 9 (e,2e) processes on atomic inner shells
- 10 Spin-resolved atomic (e,2e) processes
- Index
- References
Summary
Introduction
The (e,2e) process for an atom describes an electron-impact-induced ionization event in which the momentum states of the incident and two outgoing electrons are defined, i.e., the reaction kinematics is fully specified. Due to its highly differential nature, the cross section describing this process provides a stringent test of electron-scattering theory. However, a quantum mechanically complete description of the (e,2e) process requires additional variables to be specified, namely the spin projection states of the continuum electrons, as well as angular momentum, and its projection state for the target atom before and the residual ion after the collision, respectively. While the goal of performing such a complete measurement is presently beyond experimental capabilities, (e,2e) experiments for which a subset of the quantum mechanical variables were determined have been performed. All employed beams of polarized electrons, enabling cross sections to be determined individually for the two spin states of the projectile (namely ms = ±½); others additionally resolved the angular momentum state of the target atom prior to the collision. In this chapter we will illustrate how the resolution of angular momentum states can powerfully highlight and provide new insight into specific aspects of the (e,2e) collision dynamics.
Electron spin emerges naturally from the relativistic treatment of quantum mechanics and, as a consequence, spin-resolved experiments are ideally suited to probe aspects of relativity in electron–atom scattering. Less obvious is that in the non-relativistic limit, spin-resolved measurements provide a sensitive probe to the nature of electron exchange processes in the (e,2e) ionization dynamics.
- Type
- Chapter
- Information
- Fragmentation ProcessesTopics in Atomic and Molecular Physics, pp. 243 - 267Publisher: Cambridge University PressPrint publication year: 2012