“ an mas probe is disclosed for obtaining a substantial improvement in signal to noise in triple - resonance high - resolution magic - angle - spinning nmr of samples near room temperature in high - field magnets where the magnet &# 39 ; s rt shim bore is greater than 60 mm . all critical circuit components , including the sample coils , are located along with the spinner assembly in a thermally insulated cold zone pressurized with helium gas . the spinner assembly attaches to a sealed , curved , rotor - loading tube to permit automatic sample change , and it is surrounded by a partially insulated jacket cooled with a cryogenic fluid , generally nitrogen gas . the mas probe is also compatible with magic angle gradients , variable temperature operation , field locking , and commonly available closed - cycle cold fingers .”