Cryogen-free 400 MHz (9.4 T) solid state MAS NMR system with liquid state NMR potential

Abstract

We show that the temporal magnetic field distortion generated by the Cold Head operation can be removed and high quality Solid-State Magic Angle Spinning NMR results can be obtained with a cryogen-free magnet. The compact design of the cryogen-free magnets allows for the probe to be inserted either from the bottom (as in most NMR systems) or, more conveniently, from the top. The magnetic field settling time can be made as short as an hour after a field ramp. Therefore, a single cryogen-free magnet can be used at different fixed fields. The magnetic field can be changed every day without compromising the measurement resolution.