Abstract 

Using Symmetry to Design Pulse Sequences in SolidState NMR,
2nd Alpine Conference on SolidState NMR, ChamonixMont Blanc, France
(Sep. 2001),
talk.
Full text (PDF) (via Malcolm H. Levitt's homepage) Symmetry theorems simplify the task of designing rotorsynchronized pulse sequences in magicangle spinning solidstate NMR. The theorems link the symmetry of the pulse sequence to selection rules for the average Hamiltonian. The pulse sequence is described by three symmetry numbers, denoted N, n and ν. The symmetry numbers n and ν correspond to winding numbers for the space and spin modulation. The symmetry number N indicates the number of steps in the rf phase modulation. By choosing N, n and ν, one can design pulse sequences with a wide range of useful properties. Two general classes have been developed: Sequences denoted CN_{n}^{ν}, which are based on a cyclic sequence element, and sequences denoted RN_{n}^{ν}, which are based on a 180° rotation element. The selection rules for these two classes are different, which creates additional flexibility. We demonstrate the following symmetries and associated applications:


Dr. Andreas Brinkmann NRC Metrology National Research Council Canada W. G. Schneider Building (M40) 1200 Montreal Road Ottawa, Ontario K1A 0R6 Canada Tel. +16139900319 Fax. +16139901555 Andreas.Brinkmann@nrccnrc.gc.ca 

Dr. Andreas Brinkmann, NRC Metrology, 1200 Montreal Road, M40,
Ottawa, ON K1A 0R6, Canada Andreas.Brinkmann@nrccnrc.gc.ca 