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Cited by 217

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Influence of Collisions upon Population of Hyperfine States in Hydrogen.

Purcell, Edward M., Field, George B.·1956·The Astrophysical Journal
DOI 10.1086/146259
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Abstract

In a collision between two hydrogen atoms in their ground states, the electron spins may exchange Such exchanges affect the relative populations of the hyperfine levels and are therefore important in determining the rate of 21-cm transitions in an assembly of atoms undergoing collision A cross-section is computed for electron exchange over a range of gas kinetic temperatures, and the competition between collisions and radiation in establishing the hyperfine populations is analyzed The results are applied to typical situations encountered in 21-cm radio astronomy

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Metadata

Authors
Purcell, E. M., & Field, G. B.
Venue
The Astrophysical Journal
Publisher
American Astronomical Society
Published
1956-11
Volume
124
Pages
542
ISSN
  • 0004-637X (ISSN-L)
  • 1538-4357
DOI
10.1086/146259
OpenAlex
W2017724816
Cited by
217
References
0
FWCI
6.33
Type
journal article
Language
en
Open access
closed

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CoChat. (2026). Citation check: Influence of Collisions upon Population of Hyperfine States in Hydrogen. https://app.cochat.ai/papers/10.1086/146259
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Purcell, E. M., & Field, G. B. (1956). Influence of Collisions upon Population of Hyperfine States in Hydrogen. The Astrophysical Journal. https://doi.org/10.1086/146259

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Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.