ring detector

Toroidal proportional gas flow counter

The X-ray and gamma-ray Ring Detector offers for material scientists feasible nondestructive surface analysis of all shapes, all surface samples or large objects (ideally from 2 cm, but even smaller samples are measurable). Without a need for assembling of an unique backgscattering geometry, the Ring Detector facilitate the measurement setup. Moreover, unlike the other gas detectors, is easielly movable on the sample surface and due to the specific design allowing 2π detection enhance the count statistics and provides faster results.

WHy to choose ring detector?

Ring detector, as a toroidal proportional gas flow counter, is able to register soft X-rays (6.4 keV) and the low-energy gamma-rays (14.4 keV) utilized in the 57Fe Mössbauer spectroscopy (backgscattering mode).

There is also an ability to perform the depth selective analysis by simultaneous registration of both conversion X-rays and backscattered gamma rays, while using a proper counting gas mixture (i.e. 45% Ar + 45% Kr + 10% CH4).

Due to its design it enhace the measurement satistics and does not force the users to setup complicated geometry adjustment in the backscatteirng or emmision experiments.

main advantages

  • toroidal design for 2π detection of radiation emitted from the surface

  • count statistic enhancement

  • for non-destructive analyzation of bulk sample surfaces

  • movable on the sample surface

  • inner hole (d. 16 mm) for primary radiation flux

  • available with shielding

  • available with optimized dual preamplifier-amplifier module

technical parameters

  • dural body, outer diameter 87 mm, high 35 mm

  • circular wolfram anode, wire diameter 50 μm

  • gas input / output connections

  • SHV high voltage connector

  • optimized with Argon90%-Methan10% mixtures

  • working with Argon/Krypton Methan mixtures

  • output gas pressure stabilization (0.2 bar above atmospheric)

  • Mylar windows, aluminized


A new prototype of a toroidal proportional gas flow counter [1] has been developed to be used in the backscattering Mössbauer spectroscopy for characterizing the surfaces of the iron bearing samples. The presented proportional counter allows to register both conversion X-rays (6.4 keV) and the backscattered gamma rays (14.4 keV) in the almost 2π geometry with the sufficient efficiency. The measured Mössbauer spectra confirm the regularity of the energy assignment. Four separate Mylar windows allows to register backscattered radiation (in one registration chamber) from the sample surface. Circular wolfram anode wire is wound in the middle of the ring on four plastic supports.

The utilization was proved in the Austenitemeter [2-4] design. Additionally other Mössbauer control system are compatible with the detector and can be used [5,6,7].

Multichannel analysis in the backscattering geometry

Detector as A part of portable device

Hand-operated portable Mössbauer spectrometer based on the same detector is also available. More info at www.austenitemeter.com.


  1. Kouřil, L.; Pechoušek, J.; Novák, P.; Navařík, J.; Kohout, P.: Toroidal proportional gas flow counter for conversion X-ray Mössbauer spectroscopy, Nuclear Instruments and Methods in Physics Research B 432, 55–59, doi:10.1016/j.nimb.2018.07.020

  2. Pechoušek, J.; Kouřil, L.; Novák, P.; Kašlík, J.; Navařík, J.: Austenitemeter – Mössbauer spectrometer for rapid determination of residual austenite in steels, Measurement 131, 671–676, doi:10.1016/j.measurement.2018.09.028

  3. Olina, A.; Píška, M.; Petrenec, M.; Hervoches, C.; Beran, P.; Pechoušek, J.; Král, P.: Assessment of Retained Austenite in Fine Grained Inductive Heat Treated Spring Steel, Materials 12(24)4063, doi:10.3390/ma12244063

  4. Austenitemeter - detector of austenite. www.austenitemeter.com

  5. Mössbauer spectrometers OLTWINS - a modular system for Mössbauer spectroscopy. www.oltwins.upol.cz

  6. MS96 – The 3rd Generation Mössbauer Spectrometer - Mössbauer equipment for every laboratory. www.mossbauer-spectrometers.com

  7. Mössbauer spectrometry at Palacký University in Olomouc, Faculty of Science: Department of Experimental Physics (DEP). www.mossbauer.upol.cz