INVESTIGADORES
MENDOZA ZELIS Pedro
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
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.