High deuteron polarization in trityl radical doped deuterated polystyrene

Deuterated polystyrene for polarized solid targets has been prepared by chemical doping with the trityl radical 'Finland D36' (AH 110 355 deutero acid form). Thin foils doped with various radical densities have been produced using tetrahydrofuran as solvent. Dynamic nuclear polarization technique has been applied to polarize deuterons in the samples (98%-D) at the temperature range of about 1 K and magnetic fields of 2.5 T and 5.0 T. A maximum deuteron polarization of −61.5% with a build-up time of 100 min has been achieved at 5.0 T and about 500 mK at a radical density of 1.16×1019 spins/g.