IFLP   13074
INSTITUTO DE FISICA LA PLATA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A programmable-velocity smooth-driven Mössbauer data acquisition system
Autor/es:
A. VEIGA; G. A. PASQUEVICH; P. MENDOZA ZÉLIS; F. H. SÁNCHEZ; N. MARTÍNEZ
Lugar:
Lima
Reunión:
Conferencia; XII Latin American Conference on teh applications of the Mössbauer Effect; 2010
Institución organizadora:
Universidad Nacional Mayor de San Marcos
Resumen:
Quality of Mössbauer spectra strongly relies upon performance of the relative velocity modulator betweensource and absorber. Traditional electromechanical driving techniques demand hard-edged square ortriangular velocity displacements that introduce long settling times and demand careful tuning.     For this work, the behavior of regular velocity transducers and drive units was carefully studiedunder different working conditions. Selected alternatives for velocity reference waveforms in bothconstant-acceleration and constant-velocity techniques were tested. Significant improvement in spec-trometer efficiency and accuracy was achieved replacing triangular and square hard edges with continu-ous smooth-shaped transitions. A criterion for best waveform selection and synchronization is presentedand attainable enhancements are evaluated.     In order to fully exploit this novel driving technique, a compact microprocessor-based architectureis proposed for a suitable data acquisition system implementation. It combines a programmable high-resolution digital waveform generator synchronized with a versatile multichannel scaler. This arrange-ment can be configured in constant-acceleration mode with velocity reference and number of channelsthat best fit a given application. The same hardware can also be used to drive the source in pro-grammable constant-velocity mode, providing a tool for recently developed tracking [1,2] and scanning[3] techniques.     Calibration and efficiency tests were addressed. A complete transmission spectrometer including thenew data acquisition system was tested. Linearity and energy resolution of the instrument are presentedand compared with conventional instrumentation performance.References   [1] P Mendoza Zélis et al 2009 Hyperfine Interact. 195 161   [2] A Veiga et al 2009 Hyperfine Interact. 188 137   [3] P Mendoza Zélis et al 2010 J. Phys.: Conf. Ser. 217 012017
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