An active feedback scheme for low field NMR experiments

Emmanuel Baudin (1) , Kayum Safiullin (1) , Steven W. Morgan (1, 2) , Pierre-Jean Nacher (1)

1 LKB (Lhomond) - Laboratoire Kastler Brossel
2 IRAMIS - Institut Rayonnement Matière de Saclay (DRF)

In low field nuclear magnetic resonance (NMR) it is desirable to combine proper characteristics of the detection scheme with a good signal to noise ratio. For example, a reduced coupling between the sample and the detection coil is needed for NMR with highly magnetized samples and a large bandwidth is required in magnetic resonance imaging (MRI). We discuss a solution based on a simple active feedback circuit that preserves the signal to noise ratio as opposed to traditional solutions which do not. We give illustrations of its use in experiments on low temperature hyperpolarized liquid 3He-4He mixtures and in hyperpolarized 3He gas MRI.

Domaines: Physique Atomique [physics.atom-ph]

Emmanuel Baudin, Kayum Safiullin, Steven W. Morgan, Pierre-Jean Nacher. An active feedback scheme for low field NMR experiments. JCNS Workshop on Modern Trends in Production and Applications of Polarized 3He, Jul 2010, Ismaning, Germany. pp.012009, ⟨10.1088/1742-6596/294/1/012009⟩. ⟨hal-00562609⟩