Magnetic shielding of parahydrogen hyperpolarization experiments for the masses

Abstract

We report on the inexpensive ($80) custom electronics for efficient robust and fast degaussing of mu-metal shields for use in parahydrogen induced polarization experiments. The degaussing process is fully automated and can be performed in ~2 seconds resulting in residual magnetic field of <20 nT. The utility of this device is demonstrated for ¹⁵N hyperpolarization of [¹⁵N₃]metronidazole below 1 microtesla. The reported electronics will be of practical use to those working in the field of parahydrogen utilizing both hydrogenative approaches for magnetic field cycling and non-hydrogenative approaches employing sub-microtesla magnetic fields to create level anti-crossing for polarization transfer from parahydrogen-derived nascent protons to the heteronucleus.