An NMR thermometer for cryogenic magic-angle spinning NMR: The spin-lattice relaxation of 127I in cesium iodide

► Measurement of the 127I T1 in CsI allows estimation of the sample temperature for temperatures down to 10 K. ► The method may be used to estimate the sample temperature in cryogenic magic-angle-spinning NMR. ► The 79Br relaxation time in CsBr allows temperature estimation down to 15 K.