Pneumatic angle adjustment for magic angle spinning spherical rotors

• DOI: 10.1016/j.jmro.2021.100014
• Publication Date: 2021-05-18T18:43:54Z
• Authors: Thomas M. Osborn ...; Nicholas H. Alaniva; Ronny Gunzenhauser; Pin-Hui Chen; Chukun Gao; Lauren E. Price; Alexander B. Barnes
• Keywords: Magic angle spinning; Magic angle; Pitch angle

Precise alignment of the sample's spinning axis is vital for many magic angle solid state NMR experiments. Spherical rotors are a new paradigm NMR, having been demonstrated to spin stably with little risk rotor crash, but like cylindrical rotors, they have previously only utilized mechanical adjustment method set rotation angle. Here we show that by using second gas aperture within stator, spherical rotor's may be precisely pitched about without or motion stator. The 2H MAS sideband lineshape carboxylic acid deuteron resonance in d4-malonic used as measure absolute deviation above below comparing experimental data simulated lineshapes. We observe linear, monotonic relationship between flow rate and pitch angle, which also accompanied an increase rate. operando control expected considerable advantages future implementation narrow-bore magnets, variable (VAS) dynamic (DAS)