Abstract: An NMR method and apparatus uses a magic angle spinning (MAS) system with a MAS turbine having a MAS stator and a MAS rotor. At least two different gases or gas mixtures are fed to the stator through separate gas feeds, a first for the driving of the rotor and another, which is different from the first, for the bearing of the rotor. Respective pressures of the at least two different gases or gas mixtures are regulated separately, and the different gases or gas mixtures are prevented from mixing in the stator by means of a flushing seal through which they at least partially flow out of the stator. Conventional outflow nozzles do not need to be adapted, and the rotor can be operated at a high rotational frequency even at low pressures. The pressures remain stable so that no rotational oscillations occur during the NMR measurement.

Abstract: A heat exchanger delivers a pressurized dry gas stream cooled to an essentially constant temperature. The gas stream circulates in a coil with a functional part immersed in a liquid fraction of a second gas in a chamber of a corresponding container, whereby a portion of the wall of the container with the chamber contacts a liquid fraction of a third gas, providing a condensation surface for the second gas. The container containing the second pressurized gas is airtight. The condensation surface is dimensioned to allow absorption of a predetermined caloric power by the gas in the chamber without significant variation of temperature/pressure. Included is a monitored variable heater of the bath of the liquid fraction of the residual gas in the container, whereby total caloric power released by the circulating gas to be cooled and by the heater is constantly kept approximately equal to the specified caloric power.

Abstract: A heat exchanger delivers a pressurized dry gas stream cooled to an essentially constant temperature. The gas stream circulates in a coil with a functional part immersed in a liquid fraction of a second gas in a chamber of a corresponding container, whereby a portion of the wall of the container with the chamber contacts a liquid fraction of a third gas, providing a condensation surface for the second gas. The container containing the second pressurized gas is airtight. The condensation surface is dimensioned to allow absorption of a predetermined caloric power by the gas in the chamber without significant variation of temperature/pressure. Included is a monitored variable heater of the bath of the liquid fraction of the residual gas in the container, whereby total caloric power released by the circulating gas to be cooled and by the heater is constantly kept approximately equal to the specified caloric power.