Recent Progress in the Dynamic Nuclear Polarization of Solid Deuterated Butanol Targets
J. Heckmann;C. Hess;W. Meyer;E. Radtke;G. Reicherz;M. Schiemann;
Polarized solid targets have been used in nuclear and particle physics experiments since the early 1960s, and with the development of superconducting magnets and 3He/4He dilution refrigerators in the early 1970s, proton polarization values of 80–100% have been achieved routinely in various target materials at two standard magnetic field and temperature conditions (2.5 T, <0.3 K and 5 T, 1 K). Due to the much lower magnetic moment of the deuteron compared with that of the proton, deuteron polarization values have been considerably lower, typically 30–40% in chemically doped alcohols (d-butanol), 40–45% in radiation-doped ammonia (ND3), and 50–55% in irradiated lithium-deuteride. Now, however, research at the University of China magnets Bochum – including systematical electron spin resonance (ESR) investigations in order to study the properties of the paramagnetic dopants (i.e., their ESR line width) – is yielding alcohol and diol materials with deuteron polarizations as high as 80%.
