Elastic, charge transfer, and related transport cross sections for proton impact of atomic hydrogen for astrophysical and laboratory plasma modeling

Abstract

Updating and extending previous work (Krstić and Schultz 1999 J. Phys. B: At. Mol. Opt. Phys. 32 3458 and other references) comprehensive calculations were performed for elastic scattering and charge transfer in proton—atomic hydrogen collisions. The results, obtained for 1301 collision energies in the center-of-mass energy range of 10−4–104 eV, are provided for integral and differential cross sections relevant to transport modeling in astrophysical and other plasma environments, and are made available through a website. Use of the data is demonstrated through a Monte Carlo transport simulation of solar wind proton propagation through atomic hydrogen gas representing a simple model of the solar wind interaction with heliospheric neutrals.

Grammage of cosmic rays in the proximity of supernova remnants embedded in a partially ionized medium

“…In the WNM and the WIM the relevant damping processes for Alfvén waves are collisions of H + with either H or He atoms. The case of H + -H collisions is special because the proton elastically scattered by the H atom is indistinguishable from the recoiling proton produced by charge exchange (Krstić & Schultz 1999;Glassgold et al 2005;Schultz et al 2008Schultz et al , 2016. Therefore, the elastic scattering and the charge exchange channels for collisions of H + with H, as for any collision between ions and their parent gas, cannot in general be separated.…”

“…The figure also shows the m.t. cross sections and rate coefficients derived from either charge exchange and elastic scattering in the distinguishable particle approach (Schultz et al 2008(Schultz et al , 2016, and the experimental determination of the m. t. cross section obtained by Brennan & Morrow (1971) by measuring the attenuation of Alfvén waves propagating in a partially-ionized hydrogen plasma at Ecm ≈ 5 eV. Also shown in Fig.…”

Angular Scattering in Charge Exchange: Issues and Implications for Secondary Interstellar Hydrogen

“…This quantum indistinguishability is overcome if spins of colliding particles are known. Schultz et al (2016) showed that the difference between the sum of the integral cross sections of elastic scattering and charge exchange for particles with known spins and the elastic scattering approach for indistinguishable particles is smaller than 5% for CM energies larger than 0.01 eV and significantly decreases for higher energies. Therefore, for heliospheric studies, separation of elastic and charge exchange collisions is justified.…”

“…Differential cross sections for the charge exchange between hydrogen atoms and protons is mostly known from theoretical calculations (Hodges & Breig 1991;Krstic & Schultz 1999;Schultz et al 2008). Recently, Schultz et al (2016) provided a comprehensive set of cross sections for energies from 10 -4 eV to 10 4 eV. In this study, we apply the results of Schultz et al (2016) to determine the impact of the momentum transfer due to scattering in charge exchange collisions on distributions of the secondary populations of ISN hydrogen atoms.…”

“…Recently, Schultz et al (2016) provided a comprehensive set of cross sections for energies from 10 -4 eV to 10 4 eV. In this study, we apply the results of Schultz et al (2016) to determine the impact of the momentum transfer due to scattering in charge exchange collisions on distributions of the secondary populations of ISN hydrogen atoms.…”