Ionization of water molecules by fast charged projectiles

Abstract

Single-ionization cross sections of water molecules colliding with fast protons are calculated from lowest-order perturbation theory by taking all electrons and molecular orientations consistently into account. Explicit analytical formulas based on the peaking approximation are obtained for differential ionization cross sections with the partial contribution from the various electron orbitals accounted for. The results, which are in very good agreement with total and partial cross sections at high electron and projectile energies, display a strong variation on molecular orientation and molecular orbitals.

Ionization of water molecules by proton impact: Two nonperturbative studies of the electron-emission spectra

“…It is important to note that, until now, only the calculations based on the first Born approximation of Refs. [5,8] …”

“…Since water is the main constituent of the cell, the biological damage is caused, to a large extent, by secondary particles (electrons, ions, and radicals) formed by ion collisions with H 2 O (see [2] and references therein); accurate cross sections for these atomic processes are therefore required to simulate the passage of ions through biological environments. These applications have motivated several perturbative calculations [3][4][5][6][7][8] of total and differential ionization cross sections in ion + H 2 O collisions, which are in general valid for relatively high collision energies.…”

Laser pulse ionization of fixed-in-space H2O

“…For instance, the use of a single-electron, single-centre pseudo-molecular description of the electronic orbitals of the molecules is customary. Very recently, a method for water ionization crosssections by fast proton impact within a first-order perturbative approximation was published [13]. The approach used a multiple-electron Slater determinant description of the target, expanded as a sum of Gaussian-type orbitals (GTOs).…”

Lattice description of electron loss in high-energy H++H2O collisions

“…Previous calculations on ionization in ion -H 2 O collisions generally employ the independent electron approximation that assumes that the active electron moves in the average field created by the nuclei and the other electrons. In particular, electron capture and ionization cross sections have been calculated by applying the first Born approximation [3], the continuumdistorted-wave method [4,5,6,7,8,9,10], the classical trajectory Monte Carlo (CTMC) [11,12,13,14] and the semiclassical treatment with pseudostates [15,16,17,18]. The one-electron probabilities yielded by these calculations are then combined (see [19,20]) to obtain the probabilities for the many-electron processes.…”