Abstract:
The abandonment of stone quarries establishes a quarry lake ecosystem that includes soil, water, fish, and vegetarian cover. The activity concentrations (ACs) of natural radionuclides in the waters of several quarry lakes worldwide have not been investigated. In addition, the features of radionuclides, such as distribution, seasonal variability, and health risks, have not been studied. In this study, the ACs of 226Ra, 234U, and 238U were measured in a typical quarry lake in Vietnam with an area of approximately 4000 m2. The average ACs of 226Ra, 234U, and 238U were 8.3, 13.8, and 17.7 mBq L−1, respectively. The ratios of 226Ra/234U, 226Ra/238U, and 234U/238U were 0.47, 0.6, and 0.79, respectively. A linear correlation was found between ACs and water depth. The ACs predicted by the QWASI (Quantitative Water, Air, Sediment Interaction) model agree with the measured values.
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Yuki Fujii, Yu Nakazawa, Ewen Lawson Gillies, Eitaro Hamada, Masahiro Ikeno, MyeongJae Lee, Satoshi Mihara, Yuta Miyazaki, Masayoshi Shoji, Chau Thanh Tai, Tomohisa Uchida and Kazuki Ueno for COMET Collaboration
Development Of FPGA-Based Nuclear Electronics Using NI MyRIO Hardware For Small-Scale Radiation Detector Systems
Development and implementation of a wireless real-time radiation monitoring system for LINAC beam delivery monitoring
Vo Hong Hai, Phuc Tri Toan Nguyen and Hieu Trung Nguyen
Science & Technology Development Journal 2024, 27():1-7
Abstract:
Introduction: In this work, we developed a wireless, remote, real-time radiation monitoring system designed to oversee beam delivery in a radiation therapy room equipped with a medical linear accelerator (LINAC).
Methods: This system utilizes a Geiger-Müller detector paired with embedded electronic hardware to accurately record radiation count rates in real-time. The data collected by this system are transmitted through LAN/WAN networks to the internet, ensuring instantaneous accessibility. In addition, a web server and mobile application were developed to display, receive, and archive the data from the radiation counter.
Results: Our system was deployed in the radiation therapy room of the Oncology Hospital in Ho Chi Minh City, demonstrating a remarkable data reception rate of up to 99.8% over a three-day test period from June 27th to 29th, 2022. The system effectively identified beam-on instances and provided precise measurements of the number and duration of beam-on events.
Conclusion: This study demonstrates the feasibility of remote real-time radiation monitoring in medical settings and highlights the potential for enhancing radiation safety and treatment efficacy in external beam radiotherapy.
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Determining the thickness of a thin aluminum sheet using the transmission measurement of X-rays with varying energies: A comparative analysis between calibration curve fitting and artificial neural network approaches
Nguyen Thi Truc Linh, Nguyen Huynh Duy Khang, Le Thi Ngoc Trang, Huynh Dinh Chuong, Tran Thien Thanh, Huynh Truc Phuong, Hoang Duc Tam
Nuclear Instruments and Methods in Physics Research A
Abstract:
This study proposes an innovative configuration for thickness measurement based on X-ray transmission, intending to improve the precision of measuring thin aluminum sheets. In this configuration, an activation sample containing Zr, Sb, and Ba elements is irradiated by 59.54 keV gamma rays emitted from three 241Am radioactive sources with a total activity of 1.78 GBq. Subsequently, the activation sample emits fluorescent Xrays at energy levels of 15.78 keV (Zr-Kα1,2), 17.67 keV (Zr-Kβ1), 26.36 keV (Sb-Kα1,2), 29.73 keV (Sb-Kβ1), 32.2 keV (Ba-Kα1,2), and 36.38 keV (Ba-Kβ1). These X-rays are collimated into a narrow beam, which then penetrates through an absorbing sample, and is ultimately recorded by a Si(Li) detector. Two different approaches are investigated to determine the thickness of absorbing samples including Calibration Curve Fitting (CCF) and Artificial Neural Network (ANN). The CCF approach requires constructing linear calibration curves for establishing the relationship between lnR (R is the ratio of the peak areas in measurements with and without absorbing sample) and the thickness of the absorbing sample at each X-ray energy level. The sample thickness is then determined by calculating a weighted average of the measured thicknesses associated with all analyzed energy levels. This approach requires in-depth understanding of radiation physics and proficiency in X-ray spectrum analysis. Meanwhile, the ANN approach uses raw spectra obtained by the Si(Li) detector to predict the thickness of aluminum sheets, facilitating analysis without requiring human intervention. The reliability of these approaches is evaluated through experimental measurements on aluminum sheets with thicknesses ranging from 0.064 cm to 1.074 cm. The results indicate that using X-rays with many different energies leads to superior accuracy in thickness measurements compared to using X-rays with a single energy. Besides, both the CCF and ANN approaches yield relative deviations of less than 3% between the predicted and reference thicknesses. It is important to emphasize that the ANN approach represents a promising solution for automated analysis without the intervention of experts.
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Huynh Dinh Chuong, Nguyen Thi Hai Yen, Nguyen Thi My Le, Hoang Duc Tam
Applied Radiation and Isotopes Available online 29 April 2020, 109197
Abstract:
This study proposes an approach to determine the density of a liquid based on the gamma scattering method. The liquids used to determine density were poured in a cylindrical tube. This approach requires that the ratio R (the ratio of area under a single scattering peak for a liquid to that for water) increase linearly with an increase in the density of the liquid. In a certain range of density, a linear relationship was obtained between the ratio R and density, as described by a linear calibration curve with coefficients of slope and intercept, for the investigated tube diameters. In particular, the values of the slope and intercept could be expressed as mathematical functions of the diameter of the tube. For a given tube, the coefficients of slope and intercept of the linear calibration curve were obtained based on these functions, which helped determine the density of the liquid. The reliability of the proposed approach was evaluated by using it to calculate the densities of five liquids—n-hexane, diethyl ether, acetonitrile, toluene, and glycerol—using tubes with inner diameters of 1.8 cm, 2.25 cm, and 2.68 cm. The results show that the maximum relative deviation between the reference and the measured densities was 4.3%.
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