TIME-DIFFERENTIAL MOSSBAUER TOTAL EXTERNAL REFLECTION OF SYNCHROTRON-RADIATION

The effect of interference of nuclear resonant and electronic Rayleigh scattering is theoretically treated in time domain Mossbauer total ex ternal reflection. The ''interference peak'' recently observed experim entally on the total delayed reflectivity angular curve is explained b y the abrupt increasing of the ''initial excitation'' of the resonant sample at the electronic critical angle. The effect of the time depend ence of secondary radiation emission followed by nonresonant photoabso rption is predicted. It is shown that it can be used for depth selecti ve structure investigations.