Consistency test of coincidence-summing calculation methods for extended sources
O.Sima, A.De Vismes Ott, M.S.Dias, P.Dryak, L.Ferreux, D.Gurau, S.Hurtado, P.Jodlowski, K.Karfopoulos, M.F.Koskinas, M.Laubenstein, Y.K.LeeM.C.Lépy, A.Luca, M.O.Menezes, D.S.Moreira, J.Nikolič, V.Peyres, P.Saganowski, M.I.Savva, R.Semmler, J.Solc, T.T.Thanh, K.Tyminska, Z.Tyminski, T.Vidmar, I.Vukanac, H.Yucel
Abstract:
An internal consistency test of the calculation of coincidence-summing correction factors FC for volume sources is presented. The test is based on exact equations relating the values of FC calculated for three ideal measurement configurations. The test is applied to a number of 33 sets of FC values sent by 21 teams. Most sets passed the test, but not the results obtained using the quasi-point source approximation; in the latter case the test qualitatively indicated the magnitude of the bias of FC.
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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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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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Background Radiation in some Quarries and Quarry Lakes in Binh Duong Province, Vietnam
Van Thang Nguyen, Nguyen Phong Thu Huynh, Huynh Thi Yen Hong, Truong Huu Ngan Thy, Huynh Truc Phuong, Cong Hao Le
Journal of Radioanalytical and Nuclear Chemistry(2022)
Abstract:
Operation of some quarries can release radioactive materials from the deep soil to other environments that potentially impact human health. The present study investigated concentrations of radon and other radionuclides in surface soil, air, and water around two quarries in the south of Vietnam. Indoor radon concentrations ranged between 6.19 Bq m-3 and 20.6 Bq m-3. In surface soil, the average concentrations of 40K, 226Ra, and 232Th were 387, 36.5, and 44.5 Bq kg− 1, respectively. In surface soil, the average values of radioactivity found for 40K, 226Ra, 238U, and 232Th were 2.65, 1.23, 1.12, and 1.22 mBq l-1, respectively. The results show that the radioactive levels in the quarry region are found higher than in the nearby area. However, these levels are not enough for a recommendation for public health.
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