Compton scattering beyond the impulse approximation

We treat the non-relativistic Compton scattering process in which an incoming photon scatters from an N-electron many-body state to yield an outgoing photon and a recoil electron, without invoking the commonly used frameworks of either the impulse approximation (IA) or the independent particle model (IPM). An expression for the associated triple differential scattering cross section is obtained in terms of Dyson orbitals, which give the overlap amplitudes between the N-electron initial state and the (N-1) electron singly ionized quantum states of the target. We show how in the high energy transfer regime, one can recover from our general formalism the standard IA based formula for the cross section which involves the ground state electron momentum density (EMD) of the initial state. Our formalism will permit the analysis and interpretation of electronic transitions in correlated electron systems via inelastic x-ray scattering (IXS) spectroscopy beyond the constraints of the IA and the IPM.Comment: 7 pages, 1 figur

Establishing a protocol for building a pan-Canadian population-based monitoring system for early childhood development for children with health disorders: Canadian Children's Health in Context Study (CCHICS)

Introduction Health disorders early in life have tremendous impact on children's developmental trajectories. Almost 80% of children with health disorders lack the developmental skills to take full advantage of school-based education relative to 27% of children without a health disorder. In Canada, there is currently a dearth of nationally representative data on the social determinants of early childhood development for children with health disorders. Evidence from Canada and other countries indicate t

Computer Assisted Tomography Applied to Plasma Electron Distribution Functions

We consider several possible instruments based on Computer Tomography to determine space plasma distribution functions

Electron impact double ionization of neon

Electron-impact double ionization from the valence shell of neon has been measured at an incident electron energy of 3662.5 eV. Double-coincidence (e, (3-1)e) measurements have been made between the scattered electron and each of the ejected electrons in turn, ejected energies were 10 eV and 90 eV, respectively, at ejection angles of 45, 60, 90, 120 and 135 degrees with respect to the incident electron beam. Absolute four-fold-differential cross-sections have been derived from the measured data and can be interpreted in terms of a fast, single-step, shake-off process

Electron impact double ionization in magnesium

Experimental investigations of double ionization provide information on the mechanism by which two electrons can be simultaneously removed from an atom. Information on the two-electron momentum distribution function of the electrons can also be obtained from the experiments. Results for the double ionization of magnesium are summarized and new (e,3e) data presented. Under a variety of experimental conditions evidence has been found for orientation and polarization effects. In addition, the recoil momentum of the residual doubly-charged ion is often large implying large momentum transfer to the core or ionizing collisions that occur close to the nucleus