Title: Time-of-flight electron scattering from molecular hydrogen: Benchmark cross sections for excitation of the $X{}^1{\mathrm{\Sigma }}_g^{+}\to b{}^3{\mathrm{\Sigma }}_u^{+}$ transition

Abstract

The electron impact $X{}^1{\mathrm{\Sigma }}_g^{+}\to b{}^3{\mathrm{\Sigma }}_u^{+}$ transition in molecular hydrogen is one of the most important dissociation pathways to forming atomic hydrogen atoms, and is of great importance in modeling astrophysical and industrial plasmas where molecular hydrogen is a substantial constituent. Recently, it has been found that the convergent close-coupling (CCC) cross sections of Zammit et al. [Phys. Rev. A 95, 022708 (2017)] are up to a factor of 2 smaller than the currently recommended data. Here, we have determined normalized differential cross sections for excitation of this transition from our experimental ratios of the inelastic to elastic scattering of electrons by molecular hydrogen using a transmission-free time-of-flight electron spectrometer, and find excellent agreement with the CCC calculations. Since there is already excellent agreement for the absolute elastic differential cross sections, we establish benchmark differential and integrated cross sections for the $X{}^1{\mathrm{\Sigma }}_g^{+}\to b{}^3{\mathrm{\Sigma }}_u^{+}$ transition, with theory and experiment being essentially in complete agreement.

Authors:

Zawadzki, Mateusz ^[1]; Wright, R. ^[2]; Dolmat, G. ^[2]; Martin, M. F. ^[2]; Hargreaves, Leigh ^[2]; Fursa, Dmitry V. ^[3]; Zammit, Mark Christian  ^[4];

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Scarlett, Liam H. ^[3]; Tapley, Jonathan K. ^[3]; Savage, Jeremy S. ^[3]; Bray, Igor ^[3]; Khakoo, Murtadha A. ^[2]

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+ Show Author Affiliations

1. Gdańsk Univ. of Technology, Gdańsk (Poland)
2. California State Univ., Fullerton, CA (United States)
3. Curtin Univ., Perth, WA (Australia)
4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:

Thu May 24 00:00:00 EDT 2018

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:

1524401

Alternate Identifier(s):

OSTI ID: 1438951

Report Number(s):

LA-UR-18-21161
Journal ID: ISSN 2469-9926; PLRAAN

Grant/Contract Number:  

89233218CNA000001; AC52-06NA25396

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review A

Additional Journal Information:

Journal Volume: 97; Journal Issue: 5; Journal ID: ISSN 2469-9926

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

74 ATOMIC AND MOLECULAR PHYSICS