Enhancement in low field nuclear magnetic resonance with a high- Tc superconducting quantum interference device and hyperpolarized H3 e

In this work, we present a design that improves signals produced by nuclear magnetic resonance (NMR) and magnetic resonance imaging by using optical pumping and a high- Tc superconducting quantum interference device (SQUID) magnetometer. In our design for a NMR detection system, a pickup coil is coupled to the spin procession of a H3 e nucleus; the input coil is coupled to a high- Tc SQUID magnetometer; and the capacitor is connected in series to form a tank circuit resonating at the Larmor frequency of the H3 e nucleus in the measuring field. A signal-to-noise ratio gain of 2.67 over a conventional Faraday detection coil was obtained with the high- Tc SQUID detection system in a measuring magnetic field equaling 0.1128 mT, at which the central frequency was 3.66 kHz for H3 e nucleus. The improvement in the NMR signal for large-size, hyperpolarized H3 e coupled to a high- Tc SQUID-based spectrometer in low magnetic fields at room temperature is significant compared to that without flux coupling. This result may be of interest given its potential for use in a low field imager.