Transient Mössbauer spectroscopy with57Fe

Abstract: Transient Mssbauer experiments with⁵⁷Fe are described. A time resolution of 0.7 ns is achieved with a BaF₂ scintillator. Polar polyvinylidene fluoride film is shown to be well suited for producing fast mechanical modulation. Pulses of recoilless gamma radiation, of width ≈30 ns and heigth 3.5 times the Mssbauer absorption, are generated with stepwise source motion. The efficiency of transient methods in extracting Mssbauer data is demonstrated with sinusoidal motion.