Drive Modeling and Dynamic Control in Mössbauer Spectroscopy for Space & Terrestrial Applications

An important component of the Mössbauer spectrometer is the Mössbauer drive, which allows, utilizing the Doppler effect, to vary the amount of energy of the emitted gamma quanta so that it corresponds to the resonance energy and energetically excites the irradiated nuclei. This paper deals with drive modelling and control in Mössbauer spectroscopy. The equations of motion of the linear drive are derived and compared in different versions. In this context, the single-mass representation proves to be a sufficiently accurate model, which shows almost identical results compared to multibody models. This leads to a reduction of the system order from n=6 to n=2, which greatly simplifies the evaluation steps in this context and the further controller design modalities. Based on this, a heuristic control concept is developed that fundamentally revises common design approaches and opens up a broad spectrum of research. The controller design provides for a combination of signal-smoothing and signal amplifying low-pass filtering in combination with dynamic input vector normalisation. This achieves the desired frequency and amplitude response of 1.1485 · 10³ rad/s and 0.3 mm and optimises the dynamics for real laboratory use.