Search

Your search keyword '"Ouyang Xiaoping"' showing total 2,114 results
Start Over Author "Ouyang Xiaoping"
2,114 results on '"Ouyang Xiaoping"'

59. Accurate in situ rock density measurement with cosmic ray muon radiography.

Author

Pang, Jie, Li, Zhiwei, Dong, Shuning, Li, Jingtai, Mao, Xin, Ding, Hao, Wang, Hao, Guo, Xiaoming, Liu, Lei, Zhang, Jianming, Feng, Xinzhou, Liu, Bin, Ouyang, Xiaoping, and Han, Ran

Subjects
COSMIC ray muons, MUONS, COSMIC ray showers, COSMIC rays, RADIOGRAPHY, MULTIPLE scattering (Physics), TECHNOLOGICAL innovations, UNDERGROUND construction
Abstract

Muon radiography, which relies on measuring the absorption and attenuation of muons as they pass through matters, offers a new imaging technique capable of revealing the internal structure of large objects. Recent technological advancement allows for the application or testing of muon radiography in various fields, including mining, civil engineering, security check, etc. This study investigates the factors that influence muon radiography, which is used in density inversion, through simulations and experiments. The materials considered for density inversion include water, standard rock, and iron. Our simulation studies show that the number of events detected and selected has an impact on the reconstruction results, and several factors, such as multiple Coulomb scattering processes, recording time, and spatial resolution, which influence the number of muons, must be taken into account when measuring the rock density. We design and conduct a laboratory scale experiment based on the simulation results. We filter the 220 h of recording signals through time coincidence and straight-line fitting to obtain the selected events. Our results reveal that the statistical error of muons survival ratio in recording time significantly impacts the inversion result and decreases the error can improve accuracy greatly. In the experiment, the deviation between the inversion mean value and the expected value can be reduced to 2.4%–2.9% for iron, 7% for water, and 1.5% for standard rock. This density inversion approach provides insight into future density detection of underground structures. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

61. Bremsstrahlung emission and plasma characterization driven by moderately relativistic laser-plasma interactions

Author

Singh, Sushil, Armstrong, Chris D., Kang, Ning, Ren, Lei, Liu, Huiya, Hua, Neng, Rusby, Dean R., Klimo, Ondřej, Versaci, Roberto, Zhang, Yan, Sun, Mingying, Zhu, Baoqiang, Lei, Anle, Ouyang, Xiaoping, Lancia, Livia, Garcia, Alejandro Laso, Wagner, Andreas, Cowan, Thomas, Zhu, Jianqiang, Schlegel, Theodor, Weber, Stefan, McKenna, Paul, Neely, David, Tikhonchuk, Vladimir, and Kumar, Deepak

Subjects
Physics - Plasma Physics
Abstract

Relativistic electrons generated by the interaction of petawatt-class short laser pulses with solid targets can be used to generate bright X-rays via bremsstrahlung. The efficiency of laser energy transfer into these electrons depends on multiple parameters including the focused intensity and pre-plasma level. This paper reports experimental results from the interaction of a high intensity petawatt-class glass laser pulses with solid targets at a maximum intensity of $10^{19}$ W/cm$^2$. In-situ measurements of specularly reflected light are used to provide an upper bound of laser absorption and to characterize focused laser intensity, the pre-plasma level and the generation mechanism of second harmonic light. The measured spectrum of electrons and bremsstrahlung radiation provide information about the efficiency of laser energy transfer.

Published
2020
Full Text
View/download PDF

81. High Dose Response Characteristics of Hot-pressed CaF2:Mn (TLD-400) Chip

Author

SONG Xiaojing;OUYANG Xiaoping;JIANG Xinbiao

Subjects
caf2:mn, hot-pressed chip, thermoluminescence, high dose, dose response, Nuclear engineering. Atomic power, TK9001-9401, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

The thermoluminescence (TL) response characteristics of hot-pressed CaF2:Mn (TLD-400) chip at high dose level were experimentally studied by using 60Co isotope sources, and the high dose response curve of CaF2:Mn chip was obtained to meet the requirements for determining absorbed dose in the radiation-hardness test of electronic device. Irradiation experiment was performed on two sets of 60Co gamma irradiation facilities delivering the dose rate with 21.38 Gy/h and 945.5 Gy/h in State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (SKLIPR) of Northwest Institute of Nuclear Technology (NINT). A 0.6 cm3 ionization chamber traced was used to measure the dose rate of gamma irradiation field. The study result shows that the typical TL glow curve of CaF2:Mn chip at high dose level is a composite of several overlapped components, with maximum intensity appearing around 260 ℃. The actual shape of TL composite peak depends on the irradiation dose. Using the dynamic distribution points, the high dose response curve with high accuracy in the range of 1-3 500 Gy under slow heating rate was presented, which consists of two linear regions (1-500 Gy, 500-2 200 Gy) and one saturated region (2 200-3 500 Gy). In the range of 1-500 Gy and 500-2 200 Gy, the TL response increases linearly with irradiation dose, and the linear correlation coefficients (R2) are better than 0.99. But there is a great difference as large as nearly five times in the two slopes of linear range. Besides, the TL response increases no longer with increasing irradiation dose in the range of 2 200-3 500 Gy, and the saturated threshold is 2 200 Gy, which is far below the manufacturer’s nominal upper limit of 2 600 Gy. Moreover, there is no sublinear region or superlinear region before saturation, which is different from the literatures reported. The TL response per Gy increases considerably, reaching its maximum at 400 Gy, and then decreases with increasing dose. The uniformity and reproducibility of CaF2:Mn chip TL response were further evaluated. The standard deviation of 30 random thermoluminescence dosimeters (TLDs) irradiated at 50 Gy and ten repeated measurements in the identical condition at 1 000 Gy are 3.8% and 0.47%, respectively. The TL intensity of the chip stored in darkness at room temperature declines within 1% in two weeks and 4% in three weeks, respectively, which indicates that CaF2:Mn chip has excellent storage stability. After being irradiated at a saturated dose of 3 000 Gy, the TL intensity of the chip in the dose range of 500-2 000 Gy decreases by 3%-9% compared with that before saturation, and the response performance fails to restore by thermal annealing, which implies the onset of gamma radiation damage and the damage dose of about 3 000 Gy. The result provides a new reference for the application of CaF2:Mn phosphor in measuring absorbed dose of electronic device in radiation-hardness test.

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results