IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Applications of Mössbauer programmable-velocity data acquisition module
Autor/es:
A. VEIGA; G. A. PASQUEVICH; P. MENDOZA ZÉLIS; N. MARTÍNEZ; F.H. SÁNCHEZ
Lugar:
Opatija
Reunión:
Conferencia; International Conference on the Application of the Mössbauer Effect; 2013
Institución organizadora:
A. Veiga, G. A. Pasquevich, P. Mendoza Zélis, N. Martínez and F.H. Sánchez.
Resumen:
In this presentation we summarize some of the applications of the Mössbauer effect that can be implemented with a new data acquisition module (MDAQ) developed in our laboratory. This instrument is a programmable-velocity scaler which allows setting dwell-time, channel number and output waveform through a USB port. It can be programmed with almost any of the velocity references useful in Mössbauer experiments, particularly the constant-acceleration and constant-velocity waves, but also ad hoc, custom designed waves. It includes facilities for the operation in programmable-velocity mode, a technique that enables the independent selection of Doppler energy (channel) and acquisition time per channel.Regarding constant-acceleration mode, MDAQ allows to optimize the trajectory by smoothing the vertices of the triangular waveform, therefore achieving a better frequency response of the velocity drive and the electromechanical transducer.  In constant-velocity mode, the module can be setup to measure the Mössbauer effect as a function of an external parameter at a set of selected velocities (e.g. kinetics of crystallization, hyperfine parameters dependence on temperature, etc).More complex experiments can also be performed using the programmable-velocity mode. For example it is possible to measure the Mössbauer effect at a spectral region of interest (ROI) which can be modified as a function of an external parameter such as magnetic field or temperature. Moreover, this instrument allows performing Mössbauer Line Tracking (MLT) experiments. MLT is a methodology designed to record the evolution of a spectral ROI while the external parameter is varied and ROI is repositioned by a tracking algorithm.Two MDAQ modules can be simultaneously used to perform Mössbauer spectroscopy experiments dependent on an external perturbation. Besides typical acquisition of spectra versus a slow varying external parameter, such as temperature, high frequency perturbations (0.1 Hz-100 kHz) can be studied by synchronizing one of the modules with the external perturbation and the other one with the velocity wave. High frequency AC-Magnetic responses and sample vibration studies are some examples of the last type of experiment.
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