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nuclear Science and Techniques 2019年第10期30卷 85-94页

作者： Yan Wang Zhi-Jie Gu Bing Lian Jie Yang Yang-Jun Zhao department of nuclear Environmental Sciences China Institute for Radiation Protection

Uranium hexafluoride(UF6)leakage accidents represent one of the most serious classes of accidents in the gasification process in nuclear fuel manufacturing *** UF6 leakage accidents include various fault conditions,such as pipeline and valve breakages or ruptures and pipeline *** establishing goal-oriented(GO)operators that can represent multi-fault states,this study estimates the probabilities of various fault states corresponding to UF6 leakage accidents in the gasification process using the GO methodology and analyzes the system *** article expands the scope of the GO methodology and provides technical support for reliability analysis using the GO methodology in multi-fault systems.

关键词： GO methodology Operator Multi-fault state Reliability analysis UF6 leakage

Determination of gamma ray spectrometry efficiency for the attenuation coefficients of some bismuth borate glasses by MCNP and(ISOCS)techniques

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Radiation Detection Technology and Methods 2018年第2期2卷 67-74页

作者： Ahmed Y.El-Haseib Z.Ahmed Yasser B.Saddeek Radiation Safety department Egyptian Nuclear and Radiological Regulatory Authority(ENRRA)Nasr CityCairoEgypt nuclear safeguards and physical protection department Egyptian Nuclear and Radiological Regulatory Authority(ENRRA)Nasr CityCairoEgypt Physics department Faculty of ScienceAl-Azhar UniversityAssiut 71524Egypt

Background Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called *** efficiency is one of the main parameters in detection system besides many other different parameters of the *** detector in experimental physics is an instrument that converts radiation energy into an electrical signal,and this is achieved basically by either ionization or *** choice for any type of a detector(gas-filled,scintillation or semiconductor)for any application depends upon the X-ray of gamma energy range of interest.A working model is therefore developed which is capable of describing the overall NaI(Tl)detection efficiency as a function of several known *** The attenuation coefficients for the bismuth borate glasses with different concentrations were measured using gamma spectroscopy *** numerical absolute efficiency calibration of a detector can be determined by In-Situ Object Calibration Software(ISOCS)and Monte Carlo Neutral Particle version 5(MCNP5)techniques which does not require any calibration standards or reference *** By using the ISOCS and MCNP5 methodologies,the full energy peak efficiency of a scintillator detector(3“X3”NaI(Tl))exposed to Co-60 and Cs-137 gamma ray sources with average accuracy range 0.126–1.224%for the used samples can be *** used materials are ternary and are located between the detector and the source to determine the attenuation coefficients for these samples by using the calculated full energy peak efficiencies of a *** The average accuracy ranged from−1.808 to 1.960%for linear attenuation coefficient(μ),while it ranged from−1.999 to 1.888%and from−1.924 to 1.960%for half value layer(HVL)and mass linear attenuation coefficient(μm),*** The calculated values of the absolute full energy peak efficiency have been used to determi

关键词： Detection efficiency Sodium iodine(NaI) Linear attenuation coefficient(μ) Mass linear attenuation coefficient(μm) Half-value layer(HVL)

Valence Stabilization of Polyvalent Uranium Ions in Presence of Some Organic Additives during Extended Gamma Irradiation of Their Aqueous Acidic Solutions

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World Journal of nuclear Science and Technology 2015年第3期5卷 157-168页

作者： M. F. Barakat M. M. Abdelhamid department of nuclear safeguards and physical protection Nuclear and Radiological Control Authority Cairo Egypt nuclear Chemistry department Atomic Energy Authority Cairo Egypt

In gamma irradiated aqueous acidic uranium solutions, tetravalent uranium ions are easily oxidized while U(VI) ions remain unchanged. In general, valence change of polyvalent metallic ions during chemical reprocessing of spent nuclear fuel solutions can lead to undesirable effects under the influence of the existing gamma radiations. Consequently, studies on valence stabilization of Uranium ions during chemical treatment in strong gamma irradiation fields seem to be highly interesting. It has been reported before that some organic compounds proved to be effective in stabilizing the valence of Fe(II) ions during extended gamma irradiation of their acidic solutions. In the present work, valence stabilization of Uranium ions in acidic solutions in presence of different classes of organic compounds has been studied. The results showed that in case of U(IV), methanol or formic acid are capable of providing about 80% protection while ethanol or acetaldehyde can provide about 70% protection. Propanol has the least protective effect i.e. about 54%. On using U(VI) instead of U(IV) in the irradiated solutions, the uranium ions were reduced and the formed U(IV) was protected as follows: formic acid or methanol can provide 69% or 63% protection respectively while ethanol, acetaldehyde or propanol can provide 50%, 35% and 24% respectively. In any case, protection exists as long as the organic additives were not completely consumed.

关键词： Valence Stabilization Uranium(IV) Ions Radiolysis Protective Effect Competitive Reactions

Design of deformable mirrors for high power lasers

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High Power Laser Science and Engineering 2016年第2期4卷 68-74页

作者： Stefano Bonora Jan Pilar Antonio Lucianetti Tomas Mocek CNR-IFN HiLASE Centre Institute of Physics AS CR department of physical Electronics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in Prague

We present the workflow of the design, realization and testing of deformable mirrors suitable for high power diode pumped solid-state lasers. It starts with the study of the aberration to be corrected, and then it continues with the design of the actuators position and characteristic. In this paper, we present and compare three deformable mirrors realized for multi-J level laser facilities. We show that with the same design concept it is possible to realize deformable mirrors for other types of lasers. As an example, we report the realization of a deformable mirror for femtosecond lasers and for a CW CO_2 laser.

关键词： adaptive optics closed loop deformable mirror high power lasers

A Low-Cost Dual Energy CT System with Sparse Data

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Tsinghua Science and Technology 2014年第2期19卷 184-194页

作者： Yuanyuan Liu Jianping Cheng Li Zhang Yuxiang Xing Zhiqiang Chen Peng Zheng nuclear and Radiation Safety Center Ministry of Environmental Protection of China department of Engineering Physics Tsinghua University

Dual Energy CT （DECT） has recently gained significant research interest owing to its ability to discriminate materials, and hence is widely applied in the field of nuclear safety and security inspection. With the current technological developments, DECT can be typically realized by using two sets of detectors, one for detecting lower energy X-rays and another for detecting higher energy X-rays. This makes the imaging system expensive, limiting its practical implementation. In 2009, our group performed a preliminary study on a new low-cost system design, using only a complete data set for lower energy level and a sparse data set for the higher energy level. This could significantly reduce the cost of the system, as it contained much smaller number of detector elements. Reconstruction method is the key point of this system. In the present study, we further validated this system and proposed a robust method, involving three main steps：（1） estimation of the missing data iteratively with TV constraints; （2） use the reconstruction from the complete lower energy CT data set to form an initial estimation of the projection data for higher energy level; （3） use ordered views to accelerate the computation. Numerical simulations with different number of detector elements have also been examined. The results obtained in this study demonstrate that 1 ＋ 14% CT data is sufficient enough to provide a rather good reconstruction of both the effective atomic number and electron density distributions of the scanned object, instead of 2 sets CT data.

关键词： X-ray imaging dual energy CT system sparse samples reconstruction material discriminationAR^TV

The behavior of cesium adsorption on zirconyl pyrophosphate

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nuclear Science and Techniques 2016年第3期27卷 74-79页

作者： feng-li song xiao-wei yang xiao-long li wei he dan lü ji que chun-long zhang shan-gui zhao shi-jun wang yun-tao liu nuclear and Radiation Safety Center Ministry of Environmental ProtectionBeijing 100082China

Zirconyl pyrophosphate(ZrP_2O_7) was prepared and Cs adsorption behavior was *** show that the distribution coefficient of Cs adsorption on ZrP_2O_7 was about 2800 mL/*** exchange capacity of ZrP_2O_7 was0.35 mmol/*** dynamic tests,Cs can be separated from other fission products very well by ZrP_2O_*** ZrP_2O_7was stable both at high temperatures and in high concentration of nitric *** Cs adsorption by ZrP_2O_7 is a monolayer and chemical adsorption.

关键词：吸附行为磷酸锆铯动态测试分布系数交换能力裂变产物化学吸附

Henry Tye: the future of theoretical physics and advice to young researchers

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National Science Review 2021年第8期8卷 216-219页

作者： Yi-Fu Cai Sheng-Feng Yan the department of Astronomy School of Physical SciencesUSTC the National Institute for nuclear Physics in Milan

Professor Henry Tye(戴自海) is a world-renowned expert in theoretical particle physics, string theory and cosmology. He was recently the IAS Professor at the Jockey Club Institute for Advanced Study(IAS) and the Hong Kong University of Science and Technology(HKUST),and is the Horace White Professor of Physics(Emeritus) at Cornell University. He has a lot of experience in research status in both China and the United States. Recently, NSR invited Professor Yi-Fu Cai(蔡一夫) from the University of Science and Technology of China(USTC)to interview Prof. Tye on his personal views on the future of theoretical physics, his own experience, and his advice to young researchers.

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Projectile electron loss in collisions of light charged ions with helium

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Chinese Physics B 2014年第5期23卷 244-248页

作者：尹永智王赟陈熙萌 School of nuclear Science and Technology Lanzhou University department of Radiation protection Gansu Provincial Center for Disease Control and Prevention

We investigate the single-electron loss processes of light charged ions （Li^1＋,2＋, C^2＋,3＋,5＋, and O^2＋,3＋） in collisions with helium. To better understand the experimental results, we propose a theoretical model to calculate the cross section of projectile electron loss. In this model, an ionization radius of the incident ion was defined under the classical over-barrier model, and we developed ＂strings＂ to explain the processes of projectile electron loss, which is similar with the molecular over-barrier model. Theoretical calculations are in good agreement with the experimental results for the cross section of single-electron loss and the ratio of double-to-single ionization of helium associated with one-electron loss.

关键词： ion-atom collision over-barrier model electron loss

Performances of different efficiency calibration methods of high-purity-germanium gamma-ray spectrometry in an inter-comparison exercise

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nuclear Science and Techniques 2019年第3期30卷 9-14页

作者： Bao-Lu Yang Qiang Zhou Jing Zhang Shuai-Mo Yao Ze-Shu Li Wen-Hong Li Fei Tuo Key Laboratory of Radiological protection and nuclear Emergency National Institute for Radiological ProtectionChinese Center for Disease Control and Prevention

This study reports the performances of efficiency calibrations for high-purity-germanium gamma-ray spectrometry using the source-, Laboratory Sourceless Object Calibration Software(LabSOCS)-and ANGLE-based methods in an inter-comparison exercise. Although the results of LabSOCS and ANGLE for ^(241)Am emitting lowenergy gamma rays were not very satisfactory, all of the three efficiency calibration methods passed acceptance criteria. The results confirmed the reliability of the calculation codes ANGLE and LabSOCS as alternative efficiency calibration methods in high-purity-germanium gamma spectrometry. This study is likely to promote the further application of the ANGLE and LabSOCS calculation codes in radioactivity measurements.

关键词： Efficiency calibration ANGLE Laboratory Sourceless Object Calibration Software (LabSOCS) Gamma-ray spectrometry

Effects of Lead on the Initial Corrosion Behavior of 316LN Stainless Steel in High-Temperature Alkaline Solution

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Acta Metallurgica Sinica(English Letters) 2019年第1期32卷 89-97页

作者： Jia-Min Shao Cui-Wei Du Xin Zhang Li-Ying Cui Corrosion and protection Center University of Science and Technology Beijing nuclear and Radiation Safety Center Ministry of Environmental Protection of P.R.China

The effect of lead on the initial corrosion behavior of 316 LN stainless steel has been investigated by U-bend immersion experiments in 4 wt% NaOH solutions at 300 °C. Follow-up studies after soaking were carried out by scanning electron microscope, energy dispersive X-ray spectrometer, X-ray photoelectron spectrometer, Auger electron spectroscopy and Raman spectroscopy. The results show that lead affects the properties of the oxide film by changing the thickness and composition, which leads to an increase in the sensitivity of stress corrosion cracking of 316 LN stainless steel. Pits and cracks appeared on the surface of 316 LN stainless steel under both lead-free and lead-containing conditions. The corrosion products were oxides of Fe, Cr and Ni, and the main spinel structure on the surface of the film was NiCr_2O_4 under both conditions. However, in the presence of lead, the cracks and pits were more obvious, the thickness of the film increased from 50 to 200 nm, and the amount of protective NiCr_2O_4 decreased. Lead was concluded to be involved in the dehydration reactions in the form of Pb(OH)_2, which affected the normal dehydration process of the hydroxides and inhibited the formation of spinel structures. Because of the above characteristics of lead, the stability of the oxide film and its protection of 316 LN stainless steel were reduced.

关键词： PbSCC Oxide film 316LN High temperature