μDose: A compact system for environmental radioactivity and dose rate measurement

Abstract

µDose is a novel compact analytical instrument for assessing low level 238 U, 235 U, 232 Th decay chains and 40 K radioactivity. The system is equipped with a dual α/β scintillator allowing discrimination between α and β particles. The unique built-in pulse analyzer measures the amplitude of each individual pulse, its shape and the time interval between subsequent pulses. This allows the detection of pulse pairs arising from subsequent decays of 214 Bi/ 214 Po, 220 Rn/ 216 Po, 212 Bi/ 212 Po and 219 Rn/ 215 Po. The obtained α and β counts and four separate decay pair counts are used to calculate 238 U, 235 U, 232 Th and 40 K specific activities in measured samples through the use of radioactivity standards. The µDose system may be equipped with various photomultipliers and counting containers to assess radionuclide concentrations of samples of masses ranging between 0.4 g and 4 g. As a result, the user can customize the system to their needs and maximize the instrument's performance. The system is controlled by dedicated software with a graphical user interface and modules for system calibration, data visualization, specific radioactivity calculations and dose rate determination using the infinite matrix assumption.

Geology, stratigraphy and palaeoenvironmental evolution of the Stephanorhinus kirchbergensis‐bearing Quaternary palaeolake(s) of Gorzów Wielkopolski (NW Poland, Central Europe)

“…For all luminescence samples, the internal alpha‐dose rate of the etched and heavy‐liquid separated quartz was considered (Jacobs, 2004). To determine this effect µDose system (Tudyka et al , 2018) was used for finely milled subsample. Using an alpha‐efficiency value of 0.04 (Rees‐Jones, 1995), internal alpha‐dose rates were calculated.…”

The µDose-system: determination of environmental dose rates by combined alpha and beta counting – performance tests and practical experiences

“…Since the activities are derived from the net count rates of the detected decay pairs using equations for which pair specific calibration parameters are needed (cf., Tudyka et al, 2018), these parameters have to be determined for each µDose-device by performing calibration measurements on material of known activities. The µDose-systems can be calibrated for different amounts of sample material using calibration material distributed by the manufacturer.…”

“…So far, the performance of the µDose-system has only been tested on one synthetic sample with known activity composed as a mixture of different IAEA standards and on a very limited number of natural loess and archaeological samples (cf. Tudyka et al, 2018Tudyka et al, , 2020. In order to assess the performance of the µDose-system for natural samples on a broader data basis, we carried out a series of inter-laboratory comparisons including TSAC, ICP-OES and low-level HRGS measurements.…”

“…For details on how decay pairs are statistically identified and for a thorough description of formulas and assumptions used for calculating the specific contributions arising from the different decay series, the reader is referred to Tudyka et al (2018).…”

Chronostratigraphy of Late Glacial aeolian activity in SW Poland – A case study from the Niemodlin Plateau

“…The lines 234 For luminescence dating, coarse grains of quartz were used with standard measurement procedures, however, when determining the annual dose of sediment, we also used, in addition to the standard high resolution γ spectrometry, the new µDose system. Dose rates, from both systems, were calculated using software that is built in the µDose system (Tudyka et al, 2018). This software uses uncertainty correlations and it propagates them using Monte Carlo method.…”