COMPARATIVE STUDY OF SIMULATION AND EXPERIMENT IN DETERMINING 192Ir SOURCE STRENGTH FOR BRACHYTHERAPY QUALITY ASSURANCE
Tran Thi Bao Ngoc, Phan Quoc Uy, Le Quang Vuong, Tran Thien Thanh, Chau Van Tao
Radiation Physics and Chemistry
Abstract:
This research is of paramount importance as it combines experimental measurements and Monte Carlo simulation to determine the air kerma strength of the 192Ir source, which plays a crucial role in dose calculations for brachytherapy treatment planning. The air kerma strength represents the source strength value, directly influencing the accuracy of dose calculations in cancer treatments. Verifying the source strength during each source exchange is essential to the quality assurance process.
In this study, the 192Ir Gammamed Plus source, provided by Varian, was used to calculate the air kerma strength through experimental measurements and Monte Carlo simulation. The measurements were conducted on a brachytherapy system with an HDR 1000 Plus well-type ionization chamber and source tube 70010 from Standard Imaging. Using the MCNP6 code, we constructed a model equivalent to the experimental system, consisting of the source geometry, source tube, and well-type chamber, with source self-absorption also considered.
The air kerma strength measurements differed from the certified value by less than 2%, within the allowable range according to the AAPM TG40 recommendations. The experimental and simulation methods showed strong agreement, with less than 4.1% discrepancies. Considering source self-absorption, the air kerma strength calculation for the 192Ir source was consistent across both methods. The findings of this study validate that we successfully built an experimental system model using the Monte Carlo simulation with the MCNP6 code. This model can be further developed for future research.
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The COMET Collaboration
Abstract:
The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus (μ–e conversion, μ−N → e−N); a lepton flavor- violating process. The experimental sensitivity goal for this process in the Phase-I experiment is 3.1 × 10−15, or 90% upper limit of a branching ratio of 7 × 10−15, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the μ–e conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.
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Combination of experimental and simulation methods for determination of effective atomic number by Rayleigh-Compton scattering technique
Le Hoang Minh, Van Thi Thu Trang, Tran Thien Thanh
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY 2025
Abstract:
This paper presents the gamma scattering technique to determine substance' component concentrations. The experimental and simulated R/C ratios of binary oxide samples (Fe2O3and SiO2) were measured. The concentration of each element were interpolated, with a bias relative less than 5% for the elements in the reference samples. The elements' experimental and theoretical Rayleigh-Compton ratio values had a robust relationship in the equation RexpR/C=1.03×RtheoR/C (n = 11; r = 0.99; p-value < 0.01). The Zeff interpolation results and the calculation results from the theoretical formulas have good agreement with an average difference of 5%.
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Nguyen Anh TUAN and Chau Van TAO
Nuclear Technology & Radiation Protection: Year 2020, Vol. 35, No. 1, pp. 36-41
Abstract:
An electron beam from the UELR-10-15S2 accelerator (average energy of 9.92 ± 0.48 MeV) was applied to irradiate food and medical items at the Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute, Vietnam. The materials are under an electron beam window, such as irradiation products, conveyor, magnet and shielding mate- rial for the magnet coil, bombarded by electrons and generated X-ray (bremsstrahlung effect). In this article, X-ray conversion efficiency from polypropylene, aluminum, iron, and lead bombarded by an electron beam from the UELR-10-15S2 accelerator is measured by the film dosimeter and simulated by the MCNP4c2 code, and there is good agreement between the calculation and measurement results. The results show that X-ray conversion efficiency is the highest from lead (4.3 %), so the gamma - neutron reaction (Q-value of –6.74 MeV for 207Pb) has to be studied in food and medical items irradiated by a 10 MeV eelectron beam.
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Nguyen Huu Quyet, Le Hong Khiem, Trinh Thi Thu My, Nguyen Thi Bao My, Marina Frontasieva, Inga Zinicovscaia, Nguyen An Son, Tran Thien Thanh, Le Dai Nam, Khuat Thi Hong, Nguyen Ngoc Mai, Trinh Dinh Trung, Duong Van Thang, Nguyen Thi Thuy Hang
Environmental Engineering and Management Journal
Abstract:
Atmospheric deposition of chemical elements in the Hanoi region has been investigated in this study based on moss biomonitoring. Twenty-seven Barbula indica moss samples were collected from the end of 2016 to the beginning of 2017, and the concentrations of 33 chemical elements in the samples were determined by instrumental neutron activation analysis. The results show that Hanoi’s air is highly polluted with Zn, Ba and Ta, and slightly polluted with Al, Cl, Sc, Ti, V, Cr, Mn, Fe, Ni, Co, As, Cd, Sb, La, Ce, Sm, Gd, Tb, Yb, Hf, Th and U. A determination of the possible pollution sources has been made for the analyzed elements; namely: coal and oil combustion are the main sources of V, Ni, Co and As; vehicle exhaust and non-exhaust sources, as well as industrial emissions, are the main sources of Mn, Co, Cd and Ba; construction dust is the source of Ca, Mg and Sb; various industries are the sources of Cr and Ni; the dust from cement kilns and ash from biomass burning is responsible for K and Cl; two-stroke motor vehicles, galvanizing factories and tire wear are the sources of Zn; and Br may be emitted from burning wastes.
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