Session Q32 - Spectroscopic Techniques.
ORAL session, Wednesday morning, March 14
Room 620, Washington State Convention Center
Synchrotron Mossbauer Spectroscopy (SMS), or coherent nuclear resonant scattering of synchrotron radiation, has become an established technique for hyperfine interaction studies with a wide range of applications. SMS spectra are recorded in the time domain. However, in order to extract the hyperfine interaction parameters in an unambiguous way, one would have to convert a measured time spectrum into an energy spectrum. This cannot be done by simple Fourier transformation since the information on the phase of the scattered wavefield is lost during the measurement. In this contribution a solution is presented. The phase can be obtained by using a reference sample and recording four different time spectra: one from the reference, one from the sample under investigation and two spectra where the scattered wavefields from sample and reference interfere. The latter can be achieved experimentally with an X-ray interferometer. Moreover, in one of the interference spectra the reference wave has been phase shifted by 90 degrees. By properly combining the four time spectra one can obtain the phase of the radiation scattered from the sample, and this also allows one to construct the energy spectrum of the sample. In this way, the hyperfine interaction parameters can be determined in a unique and unambiguous way.
This work was supported by U.S. Department of Energy, Basic Energy Sciences, Office of Science, under Contract No. W-31-109-Eng-38.