Nuclear Spin Polarization―Dynamic Nuclear Polarization Using Photo-Excited Triplet Electrons

Abstract

Nuclear spin polarization and techniques to improve it are reviewed. Although the conventional Dynamic Nuclear Polarization (DNP) technique can polarize nuclear spins up to 100%, it has been difficult to use it as a polarized target for unstable nuclear physics. We have therefore developed a low-field and high-temperature polarization technique using Triplet-DNP. Using pentacene as a polarizing agent, the hyperpolarized electron can be produced independent of experimental conditions, and ¹H polarization of 40% was achieved at 0.65 T and room temperature. We also constructed a polarized target to perform as the neutron spin filter, and to measure the spin-orbit potential of neutron-rich helium isotopes.