Impact of Nonlocality Effects in Proton Optical Potential from Folding Model on p+ 16O Elastic Scattering at Low Energies
Nguyen Hoang Phuc, Nguyen Tri Toan Phuc & Do Cong Cuong
Braz J Phys 54, 226 (2024)
Abstract:
We employ the single folding model to calculate the optical potential (OP) for the p+16O scattering system, in which the exchange term of the OP is nonlocal. In most studies, this term is approximated to a local form to simplify the calculations. In this work, the folding OP, including the nonlocal exchange term, is constructed based on the CDM3Y3 effective nucleon-nucleon (NN) interaction. The Schrödinger equation for the nucleon-nucleus scattering with the nonlocal OP is solved exactly using the Lagrange-mesh R-matrix method. By comparing the scattering cross sections calculated with the nonlocal potential and the localized approximation, we can assess the impact of the nonlocality effects in proton-nucleus elastic scattering. The calculated results demonstrate that the nonlocality effect of the OP significantly influences the low-energy elastic scattering cross sections of p+16O .
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Nguyen Le Anh , Nguyen Hoang Phuc , Dao T. Khoa , Le Hoang Chien , Nguyen Tri Toan Phuc
Nuclear Physics A 1006 (2021) 122078
Abstract:
The proton radiative capture 12,13C(p, γ ) reactions at astrophysical energies, key processes in the CNO cycle, are revisited in the potential model with the proton-nucleus potential for both the scattering and bound states obtained in the folding model, using a realistic density dependent nucleon-nucleon interaction. For the consistency, this same folding model is also used to calculate the optical potential of the elastic p+12,13C scattering at energies around the Coulomb barrier. The folded p+12,13C optical potentials are shown to account well for both the elastic p+12,13C scattering and astrophysical S factors of the radiative capture 12,13C(p, γ ) reactions.
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Yu Nakazawa, Tai Thanh Chau, Yuki Fuji, Masahiro Ikeno, Satoshi Mihara, Masayoshi Shoji, Tomohisa Uchida, Kazuki Ueno, Myeong Jae Lee
Proceedings of Science, European Physical Society Conference on High Energy Physics - EPS-HEP2019 - 10-17 July, 2019
Abstract:
The COMET Phase-I experiment searches for a neutrinoless muon-to-electron conversion which has never been observed yet. The world’s highest intensity muon beam is applied, and it leads to an unacceptable trigger rate of O (106 ) Hz. For stable data collection, the trigger rate must be reduced to O(103)Hz. This requirement is met using online event classification in the detector system which holds 99% of signal events. This classification is performed by an FPGA-based trigger system, and its processing time is set to less than 5μs by a buffer size of the detector readout electronics. A prototype board for the trigger system was developed, and communica- tion systems for related electronics devices were also constructed. From test results, the total processing time is estimated to be 2.8 μ s , which meets the requirement. We have also devel- oped an online self-trigger system for cosmic-rays and confirmed the feasibility of this hardware logic. The trigger electronics were installed in a setup for cosmic-ray measurement, and the data acquisition was successfully done using the self-trigger system.
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N.T. Anh, L.X. Chung*, L.T. Anh, T.T. Anh, M. La Cognata, M.V. Dien, B.T. Hoa, N.T. Hung, P.D. Khue, D.T.K. Linh, N.T. Nghia, N.H. Phuc, N.T.T. Phuc, G.G. Rapisarda, M. Sferrazza, and D.T. Tran
IEEE TRANSACTIONS ON NUCLEAR SCIENCE
Abstract:
A Faraday cup (FC) suitable for nA intensive beams has been developed to be used in nuclear reaction studies using the pelletron at Hanoi University of Science (HUS) - Vietnam National University (VNU). Firstly, the FC operation was tested with proton beams of 0.8 and 2.63 MeV energies bombarding a 0.081 μm 197 Au target. By varying the high voltage (-HV) applied to the FC’s repeller ring, current increase due to negative charge loss as secondary electron escape was investigated. Saturation was observed at about 50 V in both experiment and simulation using the CST Studio Suite software. Subsequently, the HV was set to -350 V to ensure the measuring current’s precision. Afterward, the FC was used in an experiment to measure the cross sections of p +12C elastic scattering with Ep =0.95-3.2 MeV at the laboratory angles of 50°, 106°, 120°, 130°, and 160° for its validation and further study for this reaction. Good agreement was obtained between our new data and those reported in the literature. The new data were analyzed with the R-matrix approach. The extracted level parameters are consistent with those of previous studies.
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Evaluation of the conformity of intensity-modulated radiation therapy and volumetric modulated arc therapy using AAPM TG 119 protocol
Dang Thi Minh Tam, Phan Long Ho, Phan Quoc Uy, Nguyen Trung Hieu, Vo Tan Linh, Nguyen Thi Hoa, Nguyen Thi The Lam, Bui Thi Thuy Nga, Truong Huu Thanh, Tran Thien Thanh, Chau Van Tao
Radiation and Environmental Biophysics
Abstract:
The aim of this work was to evaluate the conformity of intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT), and verify the accuracy of the planning and delivery system used in this work based on the AAPM TG-119 protocol. The Eclipse 13.6 treatment planning system (TPS) was used to plan the TG-119 test suite, which included four test cases: MultiTarget, Prostate, Head/Neck, and C-Shape for IMRT and VMAT techniques with 6 MV and 10 MV acceleration voltages. The results were assessed and discussed in terms of the TG-119 protocol and the results of previous studies. In addition, point dose and planar dose measurements were done using a semiflex ion chamber and an electronic portal imaging device (EPID), respectively. The planned doses of all test cases met the criteria of the TG-119 protocol, except those for the spinal cord of the C-Shape hard case. There were no significant differences between the treatment planning doses and the doses given in the TG-119 report, with p-values ranging from 0.974 to 1 (p > 0.05). Doses to the target volumes were similar in the IMRT and VMAT plans, but the organs at risk (OARs) doses were different depending on the test case. The planning results showed that IMRT is more conformal than VMAT in certain cases. For the point dose measurements, the confidence limit (CLpoint) of 0.030 and 0.021 were better than the corresponding values of 0.045 and 0.047 given in the TG-119 report for high-dose and low-dose areas, respectively. Regarding the planar dose measurements, the CLplanar value of 0.38 obtained in this work was lower than that given in the TG-119 report (12.4). It is concluded that the dosimetry measurements performed in this study showed better confidence limits than those provided in the TG 119 report. IMRT remains more conformal in certain circumstances than the more progressive VMAT. Whenselecting the method of delivering a dose to the patient, several factors must be considered, including the radiotherapy technique, energy, treatment site, and tumour geometry.
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Evaluating coincidence summing factor using marinelli beaker on coaxial HPGe detector by Monte Carlo simulation and calculating
Le Hoang Minh, Le Quang Vuong, Tran Thien Thanh, Chau Van Tao
Nucl. Sci. and Tech., Vol.12, No. 1 (2022), pp. 49-55
Abstract:
This investigation aims to compare the full energy peak efficiencies in the energy range of 46-1836 keV on a type-p coaxial HPGe and estimate the coincidence summing factor for the case of Marinelli Beaker samples used by two general Monte-Carlo simulation software MCNP and PENELOPE. The radioactive nuclides used in determining the coincidence summing factor include 22Na, 60Co, 88Y, 133Ba, 134Cs, 154Eu, and 208Tl, which are prepared in HCl 2M solution and contained in a Marinelli beaker with the source’s volume of 3000 ml. The results demonstrate there is a good agreement between the two simulation software with an average discrepancy of 1.3%. On the other hand, the simulation coincidence summing factor values are also compared with the results from the calculating software ETNA with an average discrepancy of approximately 3.1%.
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