Universal Mössbauer Spectrometer

Universal Mössbauer spectrometer (UMS) is a measurement platform compatible with most commercially available components used in Mössbauer spectrometry. This creates an excellent opportunity for a system upgrade or expansion. The UMS comes as a dual-channel system capable of controlling two spectrometers at once for efficient use of your radiation sources and doubling your measuring capacity. Its versatility also enables the use of multi-detector arrangements (coincidence experiments) or employment of resonance spectrometry with a dual transducer control. In case you must switch parts in your setup, or you want to change the setup altogether, the control software enables simple rearrangement thanks to preset settings. If your application requires special on-site conditions or additional control you can use the general purpose input/output (GPIO) for simple data logging to suit your needs. The UMS is a powerful and versatile tool for nearly any MS application.

“Research facilities that use multiple Mössbauer spectroscopy arrangements can encounter a problem with having multiple accessories requiring different operational parameters making the final setup unwieldy. We had a similar problem at our department, so we developed a universal platform to unify all MS setups, making them user-friendly and easier to set up.”

Petr Novák, Lead scientist

Key Features

    • Measurement of excited state lifetime of any nuclear transition

    • System duality enables to have two MS setups using only one radiation source

    • Time differential Mössbauer spectroscopy that uses excited state lifetime measurement to improve spectra resolution

    • Paralelism permits to have two independent MS setups controlled by just one PC - two for the price of one

    • Process triggered measurement uses external trigger signal bound to the ongoing reaction to observe fast periodic changes in samples

Overview block diagram of the main systems in the UMS device.

The user interface of the currently preppared control program based on LabVIEW.

Why to use UMS

    • Compatibility with most available MS peripherals

    • Ability to run two independent spectrometers at the same time

    • Maximally utilizes radiation source in “dual” arrangement (cost effectiveness)

    • Can operate spectrometers in any currently used arrangements (TMS, backscattering MS, coincident measurements, RMS)

    • Convenient control software with preset settings

    • Built-in high voltage supply

    • Additional programmable input/output ports for custom supplementary systems

Parallelism

The UMS is built as a two channel device. That not only gives you the oportunity to use special measurement arrangements such as dual setup, TDMS, resonance spectrometry etc., but also to have two fully equipped spectrometer setups controlled by one device. These setups don't have to be the same as long as each setup requires one velocity driver and one detector at maximum. You don't have to necessarily use both channels immediately but you always have the chance to expand your measuring capabilities by acquiring a new detector and transducer set.

Process triggered measurements

The data acquisition in the UMS system can be set up in a way that enables serial spectra recording (contrary to the parallel recording in TDMS for example). If we want to observe periodic changes in the sample that can be traced back to a signal, which either directly causes or at least marks the start of the changes, then this external process trigger can divide the usually time-averaged spectra into several delta time components. Such setup can be used to observe even fast processes like magnetization, battery charging and discharging, chemical treatment etc.

Duality

The UMS is able not only to recieve signal from two detectors, but also to drive two transducers at the same time. This attribute enables the dual spectrometer setup. By shifting the velocity modulation from the radiation source to the sample-detector framework, we can have two transmission geometries utilizing one radiation source. Since operational costs of MS setups are mainly comprised of radiation source prices, this experimental setups effectivelly halves your operational costs.

Measurement of excited state lifetime

The ability of the UMS to have two detectors connected and synchronized to one measurement system enables to observe time delay between two subsequent energy emissions. For example the system can be set up in a way that we can measure the lifetime of 14.4 keV energy level in a 57Co radiation source. Detection of 122.2 keV photons serves as a start trigger where we then observe incoming 14.4 keV photons and measure the delta time of the related events. By measuring all delta times of the incident photons we can observe the decay curve.

Time differential Mössbauer spectroscopy

TDMS is a special measuring method that utilizes excited state lifetime measurement. The typical arangement is to have excited lifetime measurement for 57Co source (Det 122 for 122.2 keV photons and Det 14 for 14.4 keV). If we can establish the decay curve, we can then select photons with certain delta time to compile the final spectra. By choosing photons with sufficiently high delta time we can dramaticaly lower the energy uncertainty and thus reducing the line width. Even though it takes longer to aquire spectra with sufficient quality, the precision of the measurement can be increased by up to a third.

Block diagram of the detector 12-bit A/D converter unit in the UMS system.

Technical specification

Two 12-bit detector channels (voltage limit from -0.5 to 5 V)

Two velocity channels of excitation current from 13 to 910 mA (12-bit resolution)

Velocity modulation up to 25 mm/s, 10-50 Hz, measured in 2048 channels

Multiple velocity modes – constant acceleration (triangle, saw), constant velocity (rectangle) or custom profile

High voltage output up to 2500 V set with 12-bit resolution

Control software UI based on LabVIEW

Because we really care about the quality of our developed products and want to offer the most versatile solution to your various spectroscopic needs, we would be grateful if you could devote your time to us and fill out a short survey.

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References

[1] Stejskal, A.; Procházka, V.; Novák, P.;Dudka, M.: Mössbauer spectrometer designed for measurements of fast processes, Nuclear Instruments and Methods in Physics Research Section A 984, 164597, doi: 10.1016/j.nima.2020.164597

[2] Novák, P.; Pechoušek, J.; Procházka, V.; Navařík, J.; Kouřil, L.; Kohout, P.; Vrba, V.; Machala, L.: Time differential 57Fe Mössbauer spectrometer with unique 4π YAP:Ce 122.06 keV gamma-photon detector, Nuclear Instruments and Methods in Physics Research Section A: 832(OCT)292–296, doi: 10.1016/j.nima.2016.06.136

[3] Novák, P.; Procházka, V.; Stejskal, A.; Kopp, J.; Pechoušek, J.: Pulse length and amplitude filtration of gamma radiation detection, utilization in the 57Fe Mössbauer spectroscopy, Nuclear Instruments and Methods in Physics Research Section A940(Oct)152–155, doi: 10.1016/j.nima.2019.06.012

[4] Procházka, V.; Novák, P.; Vrba, V.; Stejskal, A.; Dudka, M.: Autotuning procedure for energy modulation in Mössbauer spectroscopy, Nuclear Instruments and Methods in Physics Research Section B 483, 55–62, doi: 10.1016/j.nimb.2020.08.015

[5] Stejskal, B.: Development of the dual Mossbauer spectrometer and the adaptation for dynamic measurement, Master thesis, Palacký University Olomouc, 2019