Dynamic nuclear polarisation in liquids at high magnetic fields

Euratom, Ispra, Italy.

Abstract

The dynamic nuclear polarisation (DNP) by relaxation interaction has been investigated in some detail in the last years. The aim of this paper is twofold :

• 1)

  The investigation of DNP is extended both theoretically and experimentally from two types of spins to systems of three and more types of spins and to triple resonance.

• 2)

  The possibility of applying DNP for signal enhancement in high resolution NMR is investigated with particular attention to the « high field limit » of this mechanism. Measurements of the DNP at different temperatures and related measurements on line width and relaxation lead to the conclusion that the high field limit in a non viscous solvent such as acetone at room temperature is of the order of 10 kilogauss.