NMR with Hyperpolarised Protons in Metals

Abstract

Proton pulse NMR, established as a versatile method in Solid State Physics, Chemistry, Biology and Medical Science, requires on the order of 10 18 nuclei to detect an electromagnetic signal in a free induction decay (FID). The main cause for this small sensitivity is the low polarisation in the order of a few ppm due to the Boltzmann distribution in the magnetic field. Thus, NMR experiments on hydrogen are limited to metals with extremely high hydrogen solubility like Pd near room temperature. Using a polarised proton beam, a NMR signal is possible with as few as 10 13 implanted nuclei. For the first time spin-spin and spin-lattice relaxation times were measured in Au and W with this technique at the Bonn cyclotron.