We explore excitation and ionization by neutron impact as a novel tool for the investigation of electron-electron correlations in helium. We present single- and double-ionization spectra calculated in accurate numerical ab initio simulations for incoming neutrons with kinetic energies of up to 150 keV. The resulting electron spectra are found to be fundamentally different from photoionization o...

The double ionization of He by either photon impact or bare ion impact are simple examples of the quantal three-body Coulomb breakup problem. For example, the double photoionization of He near threshold produces two slow moving continuum electrons in the Coulomb field of an alpha particle, which is extremely difficult for perturbation theory to handle. On the other hand, various non-perturbativ...

Singleand double-ionization processes in C6+ collisions with the He atom at an incident energy of 100 MeV/amu are studied by direct solution of the time-dependent Schrödinger equation. A time-dependent close-coupling method based on an expansion of a one-electron three-dimensional wave function in the field of He+ is used to calculate single-ionization cross sections. A time-dependent close-cou...

We investigate laser-induced nonsequential double ionization from aligned diatomic molecules, using the strong-field approximation in its length and velocity gauge formulations. Throughout, we consider that the first electron dislodges the second by electron-impact ionization. Employing modified saddlepoint equations, we single out the contributions of different scattering scenarios to the maxi...

After appropriate sample pretreatment and derivatization, uremic serum was investigated by combined high resolution gas chromatography and mass spectrometry, using both electron impact and chemical ionization methods. Electron impact and chemical ionization spectra of a number of identified (trimethylsilylated) carbohydrates and organic acids are compared. The utilization of chemical ionization...

A joint theoretical and experimental investigation is made of the influence of long-lived metastable levels on the electron-impact single ionization of C2+. It is expected that our electron cyclotron resonance ion source produces a beam with 40% of the C2+ ions in the 1s22s2 S0 ground level and 60% in the 1s 22s2p P0,2 excited levels. The comparison of nonperturbative close-coupling calculation...

This paper describes a newlydeveloped approach for simulating the hot electron effect of submicron LDD n-MOS devices. The conventional drift-diffusion (DD) method tends to overestimate the impact ionization rate by comparing with experimental data. In particular, divergency is frequently incurred while calculating the continuity equations inclusive of impact ionization terms. To cope with this ...

Silicon–germanium alloys offer a system where the ratio of the electron impact ionization coefficient ~a! and hole impact ionization coefficient ~b! varies from a value larger than unity ~in high silicon content alloys!, to a value smaller than unity ~in high germanium content alloys!. We report results for a and b for this alloy system. The electron results are based on a multivalley nonparabo...

The theoretical model, developed by Khare model, has been modified to calculate the total cross sections for K-shell, L-shell and M-shell ionization of uranium (Z=92) atom due to electron impact at incident electron energy from ionization threshold to 1 GeV. The various calculated cross sections are in remarkable agreement with available experimental data and other theoretical cross sections. P...