A theoretical study on accurate measurements of thoron with airflow-through scintillation cell method

Tang, Fangqiong; Zhuo, Weihai; Zhao, Chao; Chen, B.; Xu, Yuheng; He, Liang

doi:10.1093/rpd/ncq252

Cited by 7 publications

(6 citation statements)

References 11 publications

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“…Other factors taken into account were Lucas cell calibration data (Kritidis, 1982) and inflow decay of 220 Rn (e.g. (Tang et al, 2010)). The reference integrated concentration was calculated by multiplying the average 220 Rn concentration by the exposure time (with air-flow breaks subtracted).…”

Section: Methodsmentioning

confidence: 99%

Pilot experiments on retrospective thoron measurements by CDs/DVDs

Pressyanov

Dimitrova

Georgiev

et al. 2013

Radiation Measurements

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Section: Methodsmentioning

confidence: 99%

Pilot experiments on retrospective thoron measurements by CDs/DVDs

Pressyanov

Dimitrova

Georgiev

et al. 2013

Radiation Measurements

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“…Its inner lateral wall is coated with ZnS(Ag) scintillator to detect alpha particles. To reduce the influence of thoron decay during measurement, which has been systematically discussed in our previous study [27], a relatively higher airflow rate of 2.7 L min -1 was used for this scintillation cell. The detection chamber of the PIPS device is a cylindrical volume with a diameter of 50.0 mm and a height of 11.3 mm (V = 22.2 mL).…”

Section: Laboratory Validation and Testmentioning

confidence: 99%

“…Among these detectors, scintillation cells have gained widespread popularity owing to their high sensitivity and simplicity of use [14][15][16][17]. The thoron measurement methods employing scintillation cells can be classified into three types: (1) the grab-sample method initially developed by Hutter [15] and subsequently improved by others [16][17][18][19][20]; (2) the delayed coincidence method proposed by Giffin et al [21] and further developed by others [22][23][24][25]; and (3) the airflow-through method, which is commonly used for radon measurement but less studied for thoron measurement [26][27][28]. Although the grab-sample method and the delayed coincidence method offer an advantage over the airflow-through method as they can distinguish between thoron and radon, this disadvantage of the airflow-through method could be overcome as further elaborated in the Discussion section.…”

Section: Introductionmentioning

confidence: 99%

Thoron gas measurement using an airflow-through scintillation cell with consideration for progeny deposition

Zhao¹,

Liu²,

Chen³

et al. 2023

Preprint

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Accurate measurement of low-level thoron gas and high-accuracy calibration of thoron measurement devices are essential for assessing and preventing thoron radiological risks. This study aimed to develop a thoron gas measurement technique using an airflow-through scintillation cell for both low-level measurement and high-accuracy calibration. To achieve this, a compartment model was developed to estimate the influence of progeny deposition and accumulation on the wall of the scintillation cell to prevent overestimation of thoron. A self-developed scintillation cell was utilized to implement and validate this technique. The lower detection limit and measurement uncertainty were then evaluated to assess the feasibility of the technique for low-level measurement and high-accuracy calibration. The results showed that the compartment model effectively addressed the influence of the progeny deposition. The measurement technique achieved a lower detection limit below 100 Bq m-3 even with the coexistence of 100 Bq m-3 of radon and attained a measurement uncertainty (k = 2) below 10% when the concentration of thoron exceeded 1,000 Bq m-3. In summary, this study developed a reliable and practical thoron gas measurement technique using an airflow-through scintillation cell with consideration for progeny deposition, and is expected to contribute to the assessment and prevention of thoron radiological risk.

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“…Using different volumes of an improved cylinder scintillation cell to measure Rn-222 activity concentration by grab sample, the efficiencies for the cell volumes between 0.49 l and 1.7 l ranged between 0.038 Bq m −3 min −1 and 0.123 Bq m −3 min −1 , with an overall decrease of 15% observed when increasing the pressure from 827 hPa to 1013 hPa [11]. In the measurement experiments of Rn-220 activity concentration by airflow-through scintillation cell method, Tang et al found that a high flow rate and a large inner volume of scintillation cell, as well as a small inner volume of sampling tube, were not only preferable for measuring low levels of Rn-220 but also helpful for enhancing the measurement accuracy [12].…”

Section: Introductionmentioning

confidence: 99%

Determining the calibration factor of Rn-220 by low-pressure scintillation cell

et al. 2023

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Accurately measuring Rn-220 is crucial for evaluating natural radiation exposure. For the large volume of normal scintillation cell, the detection efficiencies for different energy of α particles decayed from Rn-222, Rn-220 and their progeny are varied. To address this, two systems of the low-pressure scintillation cell were designed to make the shortest range of α particles with minimum energy decayed from Rn-222 longer than the longest distance between any two points in the scintillation cell by reducing air pressure. Thus, the detection efficiencies of the low-pressure scintillation cell for α particles decayed from Rn-222, Rn-220 and their progeny are same. The detection efficiency of low-pressure scintillation cell for α particles can be obtained by the standard radon chamber, and then the calibration factor of Rn-220 can be determined by low-pressure scintillation. Several verification experiments were performed. The experimental results show that the detection efficiencies of Rn-222 and Rn-220 at the air pressure of 0.4P are very close and become saturated for lower values of air pressure. The calibration factor of Rn-220 calculated using the detection efficiency (0.76 ± 0.04) at the air pressure of 0.4P is 53.75 ± 2.96 Bq m-3 min-1 (k=1).

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A theoretical study on accurate measurements of thoron with airflow-through scintillation cell method

Cited by 7 publications

References 11 publications

Pilot experiments on retrospective thoron measurements by CDs/DVDs

Pilot experiments on retrospective thoron measurements by CDs/DVDs

Thoron gas measurement using an airflow-through scintillation cell with consideration for progeny deposition

Determining the calibration factor of Rn-220 by low-pressure scintillation cell

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