The μDOSE+ is an advanced system, equipped with active shielding, designed for measuring low-level alpha and beta radiation.
The μDOSE+ is an advanced, compact system for high-precision assessment of ionising radiation’s dose rate in sediment and ceramic samples. This upgraded device comes equipped with a triple scintillator, enabling low level accurate measurements. The scintillator can be reused extensively, offering practically cost-free maintenance compared with the other α and β counting systems.
Maintaining the key features of the original μDOSE, the μDOSE+ not only allows for separate measurements of α and β particles, but now also features active shielding. This is enhanced by state-of-the-art machine learning algorithms for a significant reduction of background counts.
Key advantages with our system:
- Compact size: W 22 cm x L 22 cm x H 34 cm, supporting small sample mass down to ca. 0.5 g.
- Scintillator requires no replacement.
- Combination of advanced active and passive shielding techniques
- Triple scintillator is integrated with machine learning algorithms for exceptional α, β separation and active background reduction
- Decay pairs detection from 220Rn/216Po, 219Rn/215Po, 212Bi/212Po and 214Bi/214Po
- Measures uranium, thorium, and potassium in a single assessment
- Features an improved counting chamber that provides higher counting efficiency and facilitates easier maintenance.
- Equipped with an active 222Rn and 220Rn removal system
- Multiple systems can be linked to a single PC
- Both scintillator sizes and photomultiplier can be adjusted based on application requirements
- Measurement time is typically 1-2 days for assessing dose rate, although it is dependent on the sample size and radioactivity
- Comprehensive software enables dose rate calculations under varying conditions
- No running costs linked to materials
- Offers both installation and assistance for smooth operation
Active shielding, 222Rn and 220Rn removal system
The μDOSE+ boasts a state-of-the-art active shield, enhanced with machine learning algorithms, for notable reduction in background counts. Along with this, approximately 20 kg of copper, encompassing the photomultiplier and drawer, ensures an optimal environment for precise measurements. A 222Rn and 220Rn removal system circulates air within the detector system and passes it through an activated charcoal filter
PRINCIPLE OF OPERATION
The principle of operation is described in detail in the section R&D. In short, the built-in pulse analyzer measures the amplitude of each individual pulse, the pulse shape and the time interval between subsequent pulses. This gives information about gross α and β counts detected.
Moreover, the pulse analyzer allows to detect decay pairs arising from 220Rn/216Po, 219Rn/215Po, 212Bi/212Po and 214Bi/214Po. Decay pairs, α and β particles count rates are used to quantify 238U, 235U and 232Th decay chains. The excess of β count rate is used to estimate the 40K radioactivity. Read here
Annual dose rate module for OSL/TL/EPR dating
The µDOSE+ system is supplied with easy-to-use software for radiation dose rate calculation. The α, β and γ dose rates are obtained with a high precision thanks to the built-in Monte Carlo and probabilistic modules taking full advantage of the statistical properties of the measurements performed by the instrument. This means that dose rate uncertainty and counting time can be improved. Read here
The built-in dose rate module allows to account for all the factors described in literature, like the α particle effectiveness expressed by the a-value, grain sizes, chemical etching, water content, relative sample position in the investigated profile and cosmic dose rate. These corrections are needed to obtain reliable annual dose rates in trapped charge dating.
Depending on specific user needs measurement time can span from 24 hours typical radioactivities up to 48 hours for low level radioactivity samples.
Each μDOSE+ system is delivered with a dedicated PC that has pre installed software for measurements and data analysis. Software allows measurements, calibrations of 238U, 235U, 232Th decay chains, 40K and dose rate calculations. This is available with an intuitive graphical interface. Moreover, for the user’s convenience, the input data are pre-filled with the most recently obtained values. This greatly simplifies the dose rate calculation procedure.
Due to strong radioactive sources installed in TL/OSL readers it is advised not to operate the μDOSE+ system in the same laboratory room or to provide sufficient distance between the μDOSE+ system and TL/OSL readers. Sample preparation for the μDOSE+ system requires balance with 0.003 g precision and a ball-mill. Other materials and consumables are provided with each μDOSE+ system.