Properties and Edition of NMR Spontaneous Maser Emission Spectra

Аннотация

Spontaneous maser emission provides the practical possibility for a spectral edition in methyl chloroacetate. Methyl and methylene resonances opposite to conventional nuclear magnetic resonance spectra are clearly separated within the time domain of free induction decay. Associated characteristic time delay, which represents the appropriate time from completion of the radiofrequency pulse to the signal maximum, can be properly broken on a random and a nonrandom part. Overall, the time delay is distinctively shorter about 0.296 s for methyl and longer about 0.489 s for methylene peaks, enabling spectra edition. Although maser emission reaches maximum for pulse rotation angle at 180°, it can be observed in a significantly broader range. The maser emission reveals random intensity, and its scattering range depends on the pulse rotation angle and is most limited when rotation angle is within direct vicinity of 180°. The spontaneous maser emission is triggered by thermal Nyquist noise through radiation damping. If the pulse rotation angle is sufficiently small, the amplified spin noise is observed.