Phys. Rev. A 57, 4322–4326 (1998)Nuclear spin conversion in CH3F at elevated temperaturesReceived 20 November 1997; published in the issue dated June 1998 Experimental data on the temperature dependence of the ortho-para nuclear spin conversion rate of gaseous CH3F are presented. In the range 300–750 K, the 12CH3F conversion rate increases by one order of magnitude. By contrast, the conversion rate for 13CH3F decreases with increasing temperature (for T<600K). These results are in qualitative agreement with a theoretical model based on mixing of states due to intramolecular spin-spin interactions between the molecular nuclei. Above 600 K, the rate in 13CH3F starts to increase again, indicating a possible additional mechanism for the conversion. © 1998 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevA.57.4322
DOI:
10.1103/PhysRevA.57.4322
PACS:
33.90.+h, 34.30.+h, 34.90.+q
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