Multichannel study of spin-exchange and hyperfine-induced frequency shift and line broadening in cold collisions of hydrogen atoms

Journal Article · Tue Apr 01 04:00:00 EST 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.67.042715· OSTI ID:20633988

Zygelman, B; Dalgarno, A; Jamieson, M J; Stancil, P C ^[1]

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1. Department of Physics, University of Nevada Las Vegas, Las Vegas, Nevada 89154 (United States)

We calculate the cross sections that characterize the frequency shift and broadening of the resonance magnetic hyperfine transition in atomic hydrogen due to collisions with hydrogen atoms in a masing cavity. We consider collision energies that correspond to the temperature range, 10 mK<T<1000 K, and introduce and apply a fully quantal, multichannel collision theory for the entire temperature range under consideration. Our results for the spin-exchange induced cross sections at room temperature, are in harmony with previous calculated values and experimental measurements. For the hyperfine-induced cross sections, our predicted values are in fair agreement with measurements at cryogenic temperatures with the exception of the hyperfine frequency shift at 0.5 K and 323 K for which we obtain a different sign. A study of possible resonance structures shows that they cannot be invoked to resolve the discrepancy and nor can any plausible modification of the X{sup 1}{sigma}{sub g}{sup +} and b{sup 3}{sigma}{sub u}{sup +} interaction potentials.

• OSTI ID: 20633988
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 67; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM-ATOM COLLISIONS
ATOMS
BASIC INTERACTIONS
CROSS SECTIONS
HYDROGEN
LINE BROADENING
POTENTIALS
RESONANCE
SPECTRAL SHIFT
SPIN EXCHANGE