ESR study of atomic hydrogen and tritium in solid T2 and T2:H2 matrices below 1 K. Academic Article uri icon

abstract

  • We report on the first ESR study of atomic hydrogen and tritium stabilized in solid T2 and T2:H2 matrices down to 70 mK. The concentrations of T atoms in pure T2 approached 2 1020 cm-3 (0.60%) and record-high concentrations of H atoms 1 1020 cm-3 (0.33%) were reached in T2:H2 solid mixtures where a fraction of T atoms became converted into H due to the isotopic exchange reaction T + H2 TH + H. The maximum concentrations of unpaired T and H atoms were limited by their recombination which becomes enhanced by efficient atomic diffusion due to the presence of a large number of vacancies and phonons generated in the matrices by -particles. Recombination also appeared in an explosive manner, both being stimulated and spontaneously in thick films where sample cooling was insufficient. We suggest that the main mechanism for H and T migration is physical diffusion related to tunneling or hopping to vacant sites in contrast to tunneling chemical exchange reactions which govern diffusion of H and D atoms created in H2 and D2 matrices by other methods.

published proceedings

  • Phys Chem Chem Phys

altmetric score

  • 0.25

author list (cited authors)

  • Sheludiakov, S., Ahokas, J., Jrvinen, J., Lehtonen, L., Vainio, O., Vasiliev, S., Lee, D. M., & Khmelenko, V. V.

citation count

  • 7

complete list of authors

  • Sheludiakov, S||Ahokas, J||Järvinen, J||Lehtonen, L||Vainio, O||Vasiliev, S||Lee, DM||Khmelenko, VV

publication date

  • January 2017