File:U.S. Department of Energy - Science - 048 001 001 (14066595475).jpg

ARTIST'S IMPRESSION OF DOUBLE ROTATION NUCLEAR MAGNETIC RESONANCE (NMR).

NUCLEAR MAGNETIC RESONANCE (NMR) INVOLVES THE ABSORPTION AND EMISSION OF RADIO-FREQUENCY ENERGY BY NUCLEAR SPINS AS THEY OSCILLATE AND REORIENT IN THE PRESENCE OF INTERNAL AND EXTERNALLY APPLIED MAGNETIC FIELDS. SCIENTISTS AT LBL HAVE DEVELOPED A NEW TECHNIQUE, DOUBLE ROTATION NMR, TO STUDY THE INTERACTIONS BETWEEN ATOMS IN SOLID MATERIALS. THE DOUBLE ROTATION NMR WILL IMPROVE UP TO 100 TIMES THE ACCURACY WITH WHICH SCIENTISTS CAN DISTINGUISH BETWEEN DIFFERENT SPECIFIC LOCATIONS AND POSITIONS OF ATOMS IN A SOLID. IN NMR SPECTROSCOPY, A SAMPLE IS PLACED IN A MAGNETIC FIELD, FORCING THE SPINS INTO ALIGNMENT. THE SAMPLE IS SUBJECTED TO RADIOWAVE PULSES AND THE NUCLEI ABSORBS ENERGY FROM THEM. THE NUCLEI TOPPLE OUT OF ALIGNMENT WITH THE FIELD, BUT THEN LINE UP AGAIN AS THEY LOSE THE ABSORBED ENERGY. BY MEASURING THE SPECIFIC RADIO FREQUENCIES EMITTED BY THE NUCLEI, AND THE RATE AT WHICH REALIGNMENTS OCCURS, SCIENTISTS GAIN DETAILED INFORMATION ON THE ATOMIC STRUCTURE AND MOTION OF THE SAMPLE.