The OLTWIN system is based on our originally designed electronics. The system allows to control two transducers and to read the signal out of two detectors at once. The whole system, including transducer, detector and control unit was developed as a modular system which includes many accessories allowing easy rearrangement to different experimental setups. Thanks to a robust design, our transducer OLTWINS “PIGLET” can carry the radioactive source or the scintillation detector. This feature gives us a possibility to arrange the system to a number of configurations including those which increase the efficiency of radioactive source utilization by factor of almost two. The velocity unit motion is driven by self-tuning procedure, thus no manual PID parameter adjustment is needed. The spectrometer is supplied with two automatic sample exchangers.
Advantages
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Modularity.
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Two spectrometers in one.
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Efficient using of the source activity.
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Autotuning.
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Automatic sample exchanger.
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Compatibility with different "double loud speaker" based transducers.
Basic Parameters
Linewidth
- 30 um alpha-iron (average linewidth) 0.27 mm/s
- 12 um alpha-iron (average linewidth) 0.235 mm/s
Linearity
- Velocity range: ±25 mm/s
- Frequency range: 5–60 Hz (full velocity range 25 +- is not available for all frequencies).
- Velocity profiles: triangular, saw, constant
Calibration measured on a 12 μm α-Fe sample.
Calibration measured on a 28 μm α-Fe sample (RITVERC).
Possible arrangements
Thanks to its modularity, apart form double spectrometer arrangement, the system OLTWINS can be utilized in various experimental setups/arrangement.
Double spectrometer
- Two room temperature spectra measured at once using only one source.
- Increase in the efficiency of utilization of the source by factor of 1.9.
- The detector is mounted on the transducer. The sample is positioned in front of the detector windows.
- In this arrangement the sample is moving while the radioactive source is static.
Two transmission spectrometers
Two transducers are operated with their own respective radioactive sources, running in different modes. Therefore we have two transmissions setups which can be used either for standard room temperature measurements or used with special experimental equipment, e.g. a furnace, a cryostat, an external magnetic field, reaction chamber or with automatic sample exchangers.
Emission Mössbauer spectroscopy
In the emission spectroscopy setup we investigate a sample with incorporated 57Co serving as a source of radiation. The spectrum of the sample is detected using known reference absorber with single line (usually K2Mg57Fe(CN)6). The setup is similar to that of double spectrometer. This setup allows placing the studied sample to the cryostat or furnace, so we can follow the emission spectra under different conditions.
Also in this case we can also measure two spectra of the same sample simultaneously, thus the time needed for relevant statistics decreases.
Gamma back scattering
The source and detector can be placed also into the backscattering geometry.
