CEMS box

Conversion Electron Mössbauer Spectroscopy detector

The CEMS box is designed for all the material scientists, who require Conversion Electron Mössbauer Spectroscopy (CEMS) analysis of bulk samples. In fact, it is a module that allows one a non-destructive preparation of variable shaped samples for measurement. Unlike standard CEMS gas detectors, our product does not require any noble gas fills, as it works in the vacuum.

WHy to choose cems BOX?

The Conversion Electron Mössbauer Spectroscopy (CEMS) is a powerful tool to analyze the superficial layers of iron-bearing studied samples [1-2], as it is based on the emission of conversion electrons (especially secondary K electrons with the energy of 7.3 keV and KLL Auger electrons with the energy of 5.5 keV) from the sample surface depth up to 400 nm [1].

CEMS finds its utilization in many branches of heavy iron industry, steelworks and surface treatment processes such as nitriding, thermally induced hardening, shot-peening, vibratory-peening and other forms of cold working processes, metal plating and many more [3]. CEMS is also very common in geology and mineralogy [2].

However, all the commercialy available solutions [4] are limited by relatively small and thin samples. Our CEMS box design brings one the opportunity to be not limited by the sample shape and size.

Main advantages

non-destructive analysis of bulk sample surfaces (depth up to 400 nm)
various sample shapes and sizes
high counting rates
no need of noble gases

technical parameters

part of modular system (it is possible to use your current Mössbauer spectrometer components)
custom CEMS chamber dimensions* (it can be designed according to the sample size)
works in low vacuum (~10000 Pa)

*default inner chamber size is 300 x 200 x 150 mm

secret of cems box

The secret of the CEMS box is hidden in the Air scintillation detector (ASD) [6]. It is based on the registration of light pulses produced by microdischarges in rare air caused by electrons under the presence of an electric field. The light pulses are registered by the photomultiplifier, its window is situated inside the vacuumed chamber close to the sample. The irradiation of the sample surface is provided via a vacuum sealed chamber window, which is transparent to the gamma rays. This system makes it possible to locate transducer with a radiation source outside the vacuumed chamber and makes whole detector more modular. Figure (a) demonstrates conversion X-rays Mössbauer spectrum of the CL20ES stainless steel block (annealed at 550 °C for 6 hours). The conversion electron Mössbauer spectrum of the same sample obtained by the prototype of the CEMS box is shown in figure (b).

(a) CXMS spectrum of the austenitic steel (CL20ES).

(b) CEMS spectrum of the austenitic steel (CL20ES) obtained by using the air scintillation detector as a part of CEMS box.

More powerful surface analysis

CEMS can be used in a combination with the Austenitemeter [5] (based on the Conversion X-rays Mössbauer spectroscopy) for more detailed surface analysis.

www.austenitemeter.com.

Reference

[1] J. Frydrych, M. Mashlan, J. Pechousek, and D. Jancik, “Conversion Electron Detectors for 57Fe Mössbauer Measurements,” AIP Conf. Proc., vol. 1070, no. 1, pp. 170–184, Oct. 2008, doi: 10.1063/1.3030842.

[2] G. Klingelhöfer et al., “Athena MIMOS II Mössbauer spectrometer investigation,” J. Geophys. Res. Planets, vol. 108, no. E12, pp. 8067–8084, Dec. 2003, doi: 10.1029/2003JE002138.

[3] G. Longworth, “The use of Mössbauer spectroscopy in non-destructive testing,” NDT Int., vol. 10, no. 5, pp. 241–246, Oct. 1977, doi: 10.1016/0308-9126(77)90119-5.

[4] https://www.mossbauer-spectrometers.com/

[5] J. Pechousek, L. Kouril, P. Novak, J. Kaslik, and J. Navarik, “Austenitemeter – Mössbauer spectrometer for rapid determination of residual austenite in steels,” Measurement, vol. 131, no. 6, pp. 671–676, Jan. 2019, doi: 10.1016/J.measurement.2018.09.028.

[6] A. L. Kholmetskii, O. V. Misevich, M. Mashlan, V. A. Chudakov, A. F. Anashkevich, and V. L. Gurachevskii, “Air scintillation detector for conversion electrons Mössbauer spectroscopy (CEMS),” Nucl. Instruments Methods Phys. Res. B, vol. 129, no. 1, pp. 110–116, Mar. 1997, doi: 10.1016/S0168-583X(97)00161-4.

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