Electron momentum spectroscopy of atoms, molecules, and thin films

Charge transfer in collisions of protons with water molecule at high projectile energies and small scattering angles

“…This latter process represents the basis of the Electron Momentum Spectroscopy (EMS) [2,3] and is commonly seen as the most effective method for direct investigation of both electron target distribution and electronelectron correlations [4][5][6]. In these conditions, one could objectively expect that the capture reaction at small scattering angles can also provide exclusive information in the kinematical domains beyond that of the EMS.…”

Electron momentum spectroscopy of metal carbonyls: a reinvestigation of the role of nuclear dynamics

“…Under these conditions, the transition operator depends solely upon the coordinates of the impinging electron and of the two ejected electrons. This approximation is designed for the kinematic situation on the Bethe ridge [1][2][3][4] where the momentum of the ionized electron is equal in magnitude to the momentum transferred from the incident to the scattered electron, ensuring thereby a clean ''knock-out'' process, a condition which is best satisfied experimentally by a symmetric noncoplanar set-up. In the framework of the first Born (or sudden) approximation, the incident electron is assumed to interact with the target only once.…”

“…When the incident electron only interacts with the ejected electrons and neither affects the target nor is affected by the target, the impulse approximation is considered, and a simple relationships prevails between the azimuthal angle under which the electrons are collected and the momentum of the ejected electron prior to ionization. Modeling the incident and outgoing electrons as plane waves yields ultimately the Plane Wave Impulse Approximation (PWIA) [1][2][3][4], which implies that the energies of the unbound electrons are so high that their interactions with the residual ion are negligible. Upon the assumption that all these approximations are valid (e, 2e), ionization cross-sections for specific ionization channels in EMS conditions ultimately relate to spherically averaged and resolution folded structure factors that are obtained as the square of the Fourier Transform toward momentum space of the relevant Dyson orbitals, defined [8][9][10][11] as partial overlaps between the neutral initial ground state and final ionized state.…”

“…Electron Momentum Spectroscopy [1][2][3][4] is a powerful orbital imaging technique, which enables straightforward reconstructions of electron momentum distributions associated with specific ionization channels (i.e., of orbital momentum profiles in a one-electron picture of ionization), according to an angular analysis of intensities in electron impact (e, 2e) ionization experiments [M ? e -(E 0 ?…”

Many particle spectroscopy of atoms, molecules, clusters and surfaces: international conference MPS-2016

“…The latter case, the binary reaction, is usually employed for the Electron Momentum Spectroscopy (EMS) of the target, where one measures momentum distribution of the knocked-out electron in the target. Further information on EMS can be found in review papers [14][15][16] and in the book [17]. Later, even more sophisticated experiments of both kinds were performed for (e,3e) ionization [13,15,[18][19][20].…”