High Proton Polarization by Microwave-Induced Optical Nuclear Polarization at 77 K

M. Iinuma; Y. Takahashi; I. Shaké; M. Oda; A. Masaike; T. Yabuzaki; H. M. Shimizu

doi:10.1103/PhysRevLett.84.171

High Proton Polarization by Microwave-Induced Optical Nuclear Polarization at 77 K

M. Iinuma, Y. Takahashi, I. Shaké, M. Oda, A. Masaike, T. Yabuzaki, and H. M. Shimizu

Phys. Rev. Lett. 84, 171 – Published 3 January 2000

Abstract

Protons in naphthalene and $p$ -terphenyl doped with pentacene have been polarized up to $32 %$ and $18 %$ , respectively, at liquid nitrogen temperature in a magnetic field of 0.3 T by means of microwave-induced optical nuclear polarization. The polarization was measured by nuclear magnetic resonance as well as by the neutron transmission method. The relaxation time of the proton polarization at 0.0007 T and 77 K was found to be almost 3 h and the polarization enhancement reached a record value of $8 \times 10^{4}$ . The usefulness of the method in many areas of physics and chemistry is discussed.

Received 12 January 1998

DOI:https://doi.org/10.1103/PhysRevLett.84.171

Authors & Affiliations

M. Iinuma^*, Y. Takahashi, I. Shaké^†, M. Oda^‡, A. Masaike^§, and T. Yabuzaki

Department of Physics, Faculty of Science, Kyoto University, Kyoto 606-8502, Japan

H. M. Shimizu

The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, 351-0106, Japan

^*Present address: Graduated School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Higashi, Hiroshima, 739-8526, Japan.
^†Present address: NTT Network Innovation Systems Laboratories, 1-1 Hikari-no-oka, Yokosuka, 239-0847, Japan.
^‡Present address: Sanyo Micro-electronics Laboratories, 180 Ohmori, Anpachi-cho, Anpachi-gun, 503-0195, Japan.
^§Present address: Faculty of Engineering, Fukui University of Technology, 3-6-1 Gakuen, Fukui-shi, Japan.