An improved interferometric calibrator for Mossbauer spectrometer drive systems

An improved laser-driven Michelson interferometer for calibrating and checking the linearity of Mossbauer drive systems is discussed. The design avoids velocity errors so that the calibrator may be used at velocities down to the lowest normally used in Mossbauer spectroscopy. The effect of the necessary hysteresis in the fringe-counting electronics is analysed and the use of the calibrator is demonstrated by examining the linearity of various drive systems. It is shown that recoil of the drive vibrator is the major problem in obtaining a linear velocity scale.