Köln 2004 – scientific programme

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HK: Physik der Hadronen und Kerne

HK 45: Instrumentation and Applications VI

HK 45.1: Group Report

Thursday, March 11, 2004, 16:30–17:00, C

Highest Polarizations in Deuterated Solid State Target Materials — •Stefan Goertz, Jörg Heckmann, Werner Meyer, Eric Radtke, and Gerhard Reicherz — Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum

Unlike the proton, which can be almost completely polarized even at temperatures as high as 1 K, achieving a high polarization in a deuteron system is a much more complicated task. The reason for that is the much lower magnetic moment of the deuteron in comparison to that of the proton. Since the nuclear polarization is determined by the ratio of the magnetic to the thermal energy, the only way to further enhance the deuteron polarization consists in reducing the effective temperature seen by the nuclei. Speaking in terms of the spin temperature theory, the nucleon Zeeman temperature has to be minimized. This can be done most effectively by using paramagnetic centers, which experience only a weak non-Zeeman interaction. In alcohols or diols such centers can be provided by either an irradiation with ionizing particles or by chemical doping with radicals of the trityl family. Both methods led to a substantial improvement of the maximum polarization in deuterated butanol. Maximum polarizations of about 80% have recently been measured in trityl-doped D-butanol and D-propanediol.