Double modulation ESR study of irradiated alanine

The technique of double modulation ESR (DMESR) has been employed to investigate spectroscopic species containing different spin-lattice relaxation times in the ESR spectrum from room temperature radicals of irradiated L-alanine. The spin-lattice relaxation times of these species are modulated by the rotational rate of methyl groups. The correlation times for methyl groups obtained in this study were compared and analyzed with the data from earlier ESR, electron spin echo and ENDOR measurements.