Spin-Polarized Hydrogen Depolarization Rates at High Hydrogen Halide Pressures: Hyperfine Depolarization via the HY-H Complex

Gregoris K Boulogiannis; Chrysovalantis S Kannis; Georgios E Katsoprinakis; Dimitris Sofikitis; T Peter Rakitzis

doi:10.1021/acs.jpca.9b06372

Spin-Polarized Hydrogen Depolarization Rates at High Hydrogen Halide Pressures: Hyperfine Depolarization via the HY-H Complex

J Phys Chem A. 2019 Sep 26;123(38):8130-8134. doi: 10.1021/acs.jpca.9b06372. Epub 2019 Sep 16.

Authors

Gregoris K Boulogiannis^{1

2}, Chrysovalantis S Kannis^{1

3

2}, Georgios E Katsoprinakis^{1

2}, Dimitris Sofikitis^{1

2}, T Peter Rakitzis^{1

2}

Affiliations

¹ Department of Physics , University of Crete , Herakleio , Greece.
² Institute of Electronic Structure and Laser , Foundation for Research and Technology-Hellas , 71110 Heraklion-Crete , Greece.
³ Institut für Kernphysik (IKP-4) , Forschungszentrum Jülich , Wilhelm-Johnen-Strasse 1 , 52425 Jülich , Germany.

PMID: 31483657
DOI: 10.1021/acs.jpca.9b06372

Abstract

We measure the magnetization quantum beats of spin-polarized hydrogen (SPH) and spin-polarized deuterium (SPD) with a pickup coil, from the UV photodissociation of HCl, HBr, and DI, in the 5-5000 mbar pressure range. The pressure-dependent depolarization rate is linear at low pressures and reaches a plateau at higher pressures. The high-pressure depolarization rate is observed to be proportional to the halogen nuclear electric quadrupole coupling constant. We also investigate how the presence of an inert gas, SF₆ or N₂, affects the depolarization rate. The results are explained using a model in which depolarization occurs predominantly through an HY-H intermediate species (Y = Cl, Br, I).