https://doi.org/10.1007/s100530070025
Precise measurement of hyperfine coupling in 
CH3F based on nuclear spin conversion
Laboratoire de Physique des Lasers, Atomes et Molécules, CERLA, Centre d'Études et de Recherches Lasers et Applications,
Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq Cedex, France
Received:
25
January
2000
Revised:
11
May
2000
Published online: 15 November 2000
A new method is proposed for the experimental determination
of the hyperfine coupling in molecules. The method is based
on the level-crossing effect in the spin isomer conversion in alternating
electric fields. An experiment performed with the 13CH3F molecules
has revealed the strength of the off-diagonal in K
(
) nuclear spin-spin
coupling 
kHz, which is only by 
kHz larger than
the theoretical value calculated on the basis of the molecular structure.
PACS: 31.30.Gs – Hyperfine interactions and isotope effects, Jahn-Teller effect / 32.80.Bx – Level crossing and optical pumping / 33.15.Dj – Interatomic distances and angles
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000
