Polarised emission from highly rotational excited OH(A2Σ +) radicals produced by dissociative electron-impact excitation of H2O

K. Becker, B. Stumpf, G. Schulz

Research output: Contribution to journalArticle

Abstract

The polarisation of the hydroxyl fragment radiation arising from highly rotational excited OH radicals produced in the electron-impact dissociation of H2O has been measured for incident energies ranging from just above threshold (9.3 eV) up to 500 eV. Whereas the OH fluorescence is essentially unpolarised for energies greater than about 150 eV, a significantly non-zero polarisation occurs when the impact energy approaches threshold; by monitoring either pure P-branch fluorescence or a mixture of P- and predominantly Q-branch radiation extrapolated threshold polarisations of +7 and -9%, respectively, are obtained. The sign of the polarisation at threshold implies that rapidly rotating (abnormal) hydroxyl radicals arise from a parent H2O state of symmetry A1.

Original languageEnglish (US)
Article number009
JournalJournal of Physics B: Atomic and Molecular Physics
Volume14
Issue number15
DOIs
StatePublished - 1981

Fingerprint

electron impact
thresholds
polarization
excitation
fluorescence
hydroxyl radicals
radiation
energy
fragments
dissociation
symmetry

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

@article{6f516acc6a46478b9cb21ea8cef9bba6,
title = "Polarised emission from highly rotational excited OH(A2Σ +) radicals produced by dissociative electron-impact excitation of H2O",
abstract = "The polarisation of the hydroxyl fragment radiation arising from highly rotational excited OH radicals produced in the electron-impact dissociation of H2O has been measured for incident energies ranging from just above threshold (9.3 eV) up to 500 eV. Whereas the OH fluorescence is essentially unpolarised for energies greater than about 150 eV, a significantly non-zero polarisation occurs when the impact energy approaches threshold; by monitoring either pure P-branch fluorescence or a mixture of P- and predominantly Q-branch radiation extrapolated threshold polarisations of +7 and -9{\%}, respectively, are obtained. The sign of the polarisation at threshold implies that rapidly rotating (abnormal) hydroxyl radicals arise from a parent H2O state of symmetry A1.",
author = "K. Becker and B. Stumpf and G. Schulz",
year = "1981",
doi = "10.1088/0022-3700/14/15/009",
language = "English (US)",
volume = "14",
journal = "Journal of the Physics B: Atomic and Molecular Physics",
issn = "0022-3700",
publisher = "Institute of Physics",
number = "15",

}

TY - JOUR

T1 - Polarised emission from highly rotational excited OH(A2Σ +) radicals produced by dissociative electron-impact excitation of H2O

AU - Becker, K.

AU - Stumpf, B.

AU - Schulz, G.

PY - 1981

Y1 - 1981

N2 - The polarisation of the hydroxyl fragment radiation arising from highly rotational excited OH radicals produced in the electron-impact dissociation of H2O has been measured for incident energies ranging from just above threshold (9.3 eV) up to 500 eV. Whereas the OH fluorescence is essentially unpolarised for energies greater than about 150 eV, a significantly non-zero polarisation occurs when the impact energy approaches threshold; by monitoring either pure P-branch fluorescence or a mixture of P- and predominantly Q-branch radiation extrapolated threshold polarisations of +7 and -9%, respectively, are obtained. The sign of the polarisation at threshold implies that rapidly rotating (abnormal) hydroxyl radicals arise from a parent H2O state of symmetry A1.

AB - The polarisation of the hydroxyl fragment radiation arising from highly rotational excited OH radicals produced in the electron-impact dissociation of H2O has been measured for incident energies ranging from just above threshold (9.3 eV) up to 500 eV. Whereas the OH fluorescence is essentially unpolarised for energies greater than about 150 eV, a significantly non-zero polarisation occurs when the impact energy approaches threshold; by monitoring either pure P-branch fluorescence or a mixture of P- and predominantly Q-branch radiation extrapolated threshold polarisations of +7 and -9%, respectively, are obtained. The sign of the polarisation at threshold implies that rapidly rotating (abnormal) hydroxyl radicals arise from a parent H2O state of symmetry A1.

UR - http://www.scopus.com/inward/record.url?scp=33646343896&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646343896&partnerID=8YFLogxK

U2 - 10.1088/0022-3700/14/15/009

DO - 10.1088/0022-3700/14/15/009

M3 - Article

AN - SCOPUS:33646343896

VL - 14

JO - Journal of the Physics B: Atomic and Molecular Physics

JF - Journal of the Physics B: Atomic and Molecular Physics

SN - 0022-3700

IS - 15

M1 - 009

ER -