Nuclear Bragg diffraction of synchrotron radiation in yttrium iron garnet

Monochromatization of synchrotron radiation down to about 10^-8 eV at an energy of 14.4 keV has been achieved by double nuclear Bragg diffraction from ⁵⁷yttrium iron garnet single-crystal films set for the electronically forbidden {200} reflection. The monochromatized {γ} quanta have been analyzed with respect to time delay and capabiltiy of resonance absorption. By setting of appropriate energy and time windows a pure beam of resonant {γ} quanta at a rate of about 1 Hz is available.