NUCLEAR-SCATTERING OF SYNCHROTRON-RADIATION BY TA-181

We report the first observation of excitation of the 6.2 keV nuclear l evel of Ta-181 by synchrotron radiation. The absolute energy of the le vel was determined to be 6214 +/- 2 eV. The time distribution of nucle ar forward scattering of synchrotron radiation by a 7.5 mu m Ta metal foil was measured, and a decay time of 530 +/- 80 ns was observed. Ana lysis of the time distribution reveals an inhomogeneous broadening of the nuclear resonance in this sample 6 +/- 2 natural linewidths.