Fizika Nizkikh Temperatur: Volume 46, Number 2 (February 2020), p. 172-179 ( to contents , go back )
Studies of nuclear polarization of hydrogen atoms embedded in solid molecular hydrogen and hydrogen deuteride films
S.Sheludiakov, D.M. Lee, and V.V. Khmelenko
Institute for Quantum Science and Engineering, Department of Physics and Astronomy, Texas A&M University, College Station, TX, 77843, USA
J.Ahokas, J. Järvinen, and S. Vasiliev
Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
Received August 23, 2019, published online December 27, 2019
We report on an electron-spin resonance study of nuclear polarization of hydrogen atoms embedded in solid H2 and HD films at temperatures 0.1–1.5 K and in a high magnetic field of 4.6 T. Similar to our previous work [Phys. Rev. Lett. 122, 225301 (2019)], we observed a build-up of the spontaneously (p ≃ 0.35) and highly (p ≃ 0.75) nuclear polarized phases of H atoms in the as-deposited H2 films. However, we did not obtain an enhanced nuclear polarization of H atoms in the regions of their small local concentration. We also failed to observe enhanced nuclear polarization for H atoms in the annealed H2 films as well as in the as-deposited HD sample. These observations tend to support our previous explanation for the build-up of high nuclear polarization due to the formation of weakly-bound triplet H2 molecules.
Key words: hydrogen atoms, solid molecular hydrogen, nuclear polarization.