POLARIZER ANALYZER FILTER FOR NUCLEAR RESONANT SCATTERING OF SYNCHROTRON-RADIATION

A silicon (840) channel-cut crystal with a large asymmetry is used to linearly polarize synchrotron radiation generated by an undulator sour ce at the 14.413 keV nuclear resonance of Fe-57. The resulting <(sigma )over cap>-polarized radiation is then scattered from an Fe-57 foil pl aced in a magnetic field that effects <(sigma)over cap>--><(pi)over ca p> polarization conversion within the resonant bandwidth. A second cry stal of the same type is placed in a crossed position to suppress the nonresonant radiation while transmitting the <(pi)over cap>-polarized resonant radiation. A polarization suppression factor of 6X10(-7) has been obtained. The suppression of the nonresonant radiation allowed mo nitoring the decay of the nuclear levels after 1 ns of their excitatio n. (C) 1995 American Institute of Physics.