Dynamic polarization of protons and deuterons in solid deuterium hydride
Abstract
Dynamic polarization of protons and deuterons in radiation-damaged solid deuterium hydride containing a small oxygen impurity and the parameters relating to this process have been investigated. The apparatus for preparing a sample from a gas mixture, for retaining it at liquid-helium temperature, for inflicting radiation damage, for observing its EPR and NMR spectra, and for measuring its nuclear- and electron-resonance relaxation times is described. The EPR spectra for atoms and radicals induced by radiation damage are displayed. The relaxation times of the H-atom resonances are shown to be greatly reduced when oxygen is added to the HD gas and a broad resonance appears, which is not present in purer samples and is ascribed to the radical Ȯ 2D. The following data are presented for the most successful HD sample: (1) spin-lattice relaxation times for the proton, deuteron, and electron systems; (2) enhancement of proton polarization as a function of microwave power and magnetic field for microwave frequencies of 23.93 GHz and 35.68 GHz at temperatures of 4.2 K and ≈ 1.2 K; and (3) enhancement of deuteron polarization as a function of magnetic field for 23.93 GHz at 4.2 K and 1.3 K. A proton polarization of ≈ 3 {3}/{4}% and a deuteron polarization of 0.3-0.4% have been obtained. Proton polarizations of more than 15% might be obtained if the field is raised to 25 kG and both H-atom resonances are used to drive transitions.
- Publication:
-
Nuclear Instruments and Methods
- Pub Date:
- May 1974
- DOI:
- 10.1016/0029-554X(74)90294-8
- Bibcode:
- 1974NucIM.117..477S