ENERGY-DEPENDENCE OF NUCLEAR RECOIL MEASURED WITH INCOHERENT NUCLEAR-SCATTERING OF SYNCHROTRON-RADIATION

The energy dependences of nuclear forward scattering and nuclear 4pi scattering of 14.4 keV synchrotron radiation were studied with an energy resolution of 6 meV. Nuclear 4pi scattering resulted from internal conversion and therefore represents the energy dependence of resonant nuclear absorption. In the case of the [Fe-57(bpp)2][BF4]2 sample the energy dependence of nuclear 4pi scattering revealed a 13 meV inelastic broadening of the absorption line. This indicates an excitation of lattice motions in the nuclear absorption process. The technique allows the direct measurement of the energy distribution of nuclear recoil.