AlphaSpec - Radonis 2.0
One device for measuring short-lived and long-lived alpha radionuclides.
AlfaSpec – Radonis 2.0 is a compact spectrometric instrument designed for the determination of alpha-emitting radionuclide activity, particularly short-lived radon progeny and long-lived natural radionuclides present in the workplace in the form of radioactive aerosol particles. The device enables precise determination of the potential alpha energy concentration (PAEC) as well as the equilibrium equivalent activity concentration (EEAC), both in automatic and expert modes.
The instrument employs a silicon semiconductor detector with a minimum detection efficiency of 10% (depending on the measurement geometry). It is powered by a rechargeable battery, ensuring flexibility of use in both field and laboratory conditions.
Specification of Use: Determination of PAEC/EEAC and total alpha activity concentration in air.
Environment of Use: Air in mining, underground, occupied, or residential spaces.
Sampling Method: Air sampling through a filter.
Detection Method: The instrument uses the method of direct alpha radiation detection with a semiconductor silicon detector, which registers alpha particles emitted by radionuclides deposited on the filter after air sampling.
Calculation Method: The AlfaSpec instrument determines PAEC and EEAC based on the measurement of alpha radiation emitted by radioactive aerosols collected on the filter after air sampling. After a defined air intake, the instrument analyzes the number of alpha pulses in the energy regions corresponding to radon progeny. Based on these pulses, the known volume of sampled air, and the detection efficiency, the resulting value of EEAC or PAEC is calculated. The calculation is performed automatically and is adapted to the selected sampling and measurement mode.
For the determination of total alpha activity (e.g., long-lived radionuclides from the uranium or thorium series), the measurement is performed after the decay of short-lived radionuclides (primarily radon progeny). The AlfaSpec instrument then evaluates the total alpha particle response, from which the cumulative alpha activity is determined.
AlfaSpec Dual – Radonis 2.0 is specifically designed for field determination of the unattached fraction of radon progeny. The instrument is intended for use in environments with high radon concentrations, limited ventilation, and low aerosol particle levels, where the unattached fraction can significantly contribute to irradiation of the respiratory tract.
The device enables simultaneous measurement on a diffusion screen, where the unattached fraction of radon progeny is collected, and on an aerosol filter, which captures particles with attached progeny. This approach provides comprehensive information on the distribution of short-lived radon progeny and allows more accurate assessment of inhalation dose to workers, in line with radiation protection principles.
The measured data can be used not only for immediate assessment of working conditions but also for validation of results from continuous monitors, which may systematically underestimate actual values due to losses of the unattached fraction. The instrument is therefore suitable both for operational dosimetric purposes and for research and control activities in assessing exposure in environments with variable concentrations of radon progeny.
Both devices, AlfaSpec Mono and AlfaSpec Dual, have been granted type approval in accordance with Act No. 505/1990 Coll., on Metrology. New instruments are supplied with initial verification.