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Multi-photon resonance enhanced super high-order harmonic generation

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Chinese Physics B 2010年第11期19卷 280-289页

作者：林正喆庄军宁西京 Applied Ion Beam Physics laboratory Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan University department of Optical science and Engineering Fudan University

this paper proposes highly charged ions pumped by intense laser to produce very high order harmonics. Numerical simulations and full quantum theory of Ne^9＋ ions driven by laser pulses at 1064 nm in the power range of 109 W/cm^2 1015 W/cm^2 show that the emission spectrum corresponds to the electronic transitions from the excited states to the ground state, which is very different from the spectrum of general high-order harmonic generation. In such situation, harmonic order as high as 1000 can be obtained without producing lower order harmonics and the energy conversion efficiency is close to general high order harmonic generation of hydrogen atom in the same laser field.

关键词： multi-photon excitation high-order harmonic generation

Numerical analysis on element creation by nuclear transmutation of fission products

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nuclear science and techniques 2015年第1期26卷 113-120页

作者： Atsunori terashima Masaki Ozawa department of nuclear Engineering Graduate School of Science and EngineeringTokyo Institute of Technology Research laboratory for nuclear Reactors Tokyo Institute of Technology

A burnup calculation was performed to analyze the Apr`es ORIENt process, which aims to create highlyvaluable elements from fission products separated from spent nuclear fuels. the basic idea is to use nuclear transmutation induced by a neutron capture reaction followed by a β-decay, thus changing the atomic number Z of a target element in fission products by 1 unit. LWR(PWR) and FBR(MONJU) were considered as the transmutation devices. High rates of creation were obtained in some cases of platinum group metals(44Ru by FBR,46 Pd by LWR) and rare earth(64Gd by LWR,66 Dy by FBR). therefore, systems based on LWR and FBR have their own advantages depending on target elements. Furthermore, it was found that creation rates of even Z(= Z + 1) elements from odd Z ones were higher than the opposite cases. this creation rate of an element was interpreted in terms of "average 1-group neutron capture cross section of the corresponding target element σc Z defined in this work. General trends of the creation rate of an even(odd) Z element from the corresponding odd(even) Z one were found to be proportional to the 0.78th(0.63th) power of σc Z, however with noticeable dispersion. the difference in the powers in the above analysis was explained by the difference in the number of stable isotopes caused by the even-odd effect of Z.

关键词：裂变产物元素数值分析嬗变快中子增殖反应堆轻水反应堆稳定同位素 LWR

Compensation for booster leakage field in the Duke storage ring

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Chinese Physics C 2017年第1期41卷 173-179页

作者：李为郝浩 Stepan F.Mikhailov Victor Popov 李为民吴英 National Synchrotron Radiation laboratory University of Science and Technology of China triangle University nuclear laboratory/Physics department Duke University

the High Intensity Gamma-ray Source（HIGS） at Duke University is an accelerator-driven Compton gamma-ray source, providing high flux gamma-ray beam from 1 MeV to 100 MeV for photo-nuclear physics *** HIGS facility operates three accelerators, a linac pre-injector（0.16 GeV）, a booster injector（0.16—1.2 GeV）,and an electron storage ring（0.24—1.2 GeV）. Because of the proximity of the booster injector to the storage ring, the magnetic field of the booster dipoles close to the ring can significantly alter the closed orbit in the storage ring being operated in the low energy region. this type of orbit distortion can be a problem for certain precision experiments which demand a high degree of energy consistency of the gamma-ray beam. this energy consistency can be achieved by maintaining consistent aiming of the gamma-ray beam, and therefore a steady electron beam orbit and angle at the Compton collision point. to overcome the booster leakage field problem, we have developed an orbit compensation scheme. this scheme is developed using two fast orbit correctors and implemented as a feedforward which is operated transparently together with the slow orbit feedback system. In this paper, we will describe the development of this leakage field compensation scheme, and report the measurement results, which demonstrate the effectiveness of the scheme.

关键词： field compensation feedforward storage ring beam orbit

k_(eff)uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

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nuclear science and techniques 2021年第11期32卷 105-118页

作者： Rong-Rui Yang Yuan Yuan Chen Hao Ji Ma Guang-Hao Liu Fundamental science on nuclear Safety and Simulation technology laboratory College of Nuclear Science and TechnologyHarbin Engineering UniversityHarbin 150001China department of Reactor technology Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBeijing 100089China

to benefit from recent advances in modeling and computational algorithms,as well as the availability of new covariance data,sensitivity and uncertainty analyses are needed to quantify the impact of uncertain sources on the design parameters of small prismatic high-temperature gascooled reactors(HtGRs).In particular,the contribution of nuclear data to the k_(eff)uncertainty is an important part of the uncertainty analysis of small-sized HtGR physical *** this study,a small-sized HtGR designed by China nuclear Power Engineering Co.,*** selected for k_(eff)uncertainty analysis during full lifetime burnup *** of the cold zero power(CZP)condition and full lifetime burnup process were constructed using the Reactor Monte Carlo Code RMC for neutron transport calculation,depletion calculation,and sensitivity and uncertainty *** the sensitivity analysis,the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via track length importance Characterization(CLUtCH)method was applied to obtain sensitive information,and the "sandwich" method was used to quantify the k_(eff)*** also compared the k_(eff)uncertainties to other typical *** results show that ^(235)U is the largest contributor to k_(eff)uncertainty for both the CZP and depletion conditions,while the contribution of ^(239)Pu is not very significant because of the design of low discharge *** is worth noting that the radioactive capture reaction of ^(28)Si significantly contributes to the k_(eff)uncertainty owing to its specific fuel ***,the k_(eff)uncertainty during the full lifetime depletion process was relatively stable,only increasing by 1.12%owing to the low discharge burnup design of small-sized *** numerical results are beneficial for neutronics design and core parameters optimization in further uncertainty propagation and quantification study for small-sized HtGR.

关键词： Small-sized HtGR SU analysis nuclear data Burnup

Measurement of D（d,p）t Reaction Cross Sections in Sm Metal in Low Energy Region （10 ≤ Ed ≤20 keV）

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Chinese Physics Letters 2007年第11期24卷 3103-3106页

作者：王铁山杨振 H. Yunemura A. Nakagawa 吕会议陈建勇刘盛进 J. Kasagi School of nuclear science and technology Lanzhou University Lanzhou 730000 laboratory of nuclear science Tohoku University Sendal 982-0826 Japan

to study the screening effect of nuclear reactions in metallic environments, the thick target yields, the cross sections and the experimental S（E） factors of the D（d, p）t reaction have been measured on deuterons implanted in Sm metal at 133.2K for beam energies ranging from 10 to 20 ke V. the thick target yields of protons emitted in the D（d, p）t reaction are measured and compared with those data extrapolated from cross sections and stopping power data at higher energies. the screening potential in Sm metal at 133.2K is deduced to be 520±56eV. As compared with the value achieved in the gas target, the calculated screening potential values are much larger. this screening potential cannot be simply interpreted only by the electron screening. Energy dependences of the cross section σ（E） and the experimental S（E） factor for D（d,p）t reaction in Sm metal at 133.2K are obtained, respectively.

关键词： coated conductor buffer layer self-epitaxy CeO2

Simple statistical model for predicting thermal atom diffusion on crystal surfaces

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Chinese Physics B 2013年第11期22卷 458-462页

作者：于卫锋林正喆宁西京 Institute of Modern Physics Department of Nuclear Science and Technology Applied Ion Beam Physics Laboratory Fudan University

A simple model based on the statistics of single atoms is developed to predict the diffusion rate of thermal atoms in （or on） bulk materials without empirical parameters. Compared with vast classical molecular-dynamics simulations for predicting the self-diffusion rate of Pt, Cu, and Ar adatoms on crystal surfaces, the model is proved to be much more accurate than the Arrhenius law and the transition state theory. Applying this model, the theoretical predictions agree well with the experimental values in the presented paper about the self-diffusion of Pt （Cu） adatoms on the surfaces.

关键词： adatoms diffusion Arrhenius law transition state theory molecular dynamics simulations

Efficient Formation of Large Chain Carbon Clusters

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Chinese Physics Letters 1994年第8期11卷 488-490页

作者： ZHU Lei LU Jianzhong WU Meiping LI Yufen Fudan-t.D.lee Physics laboratory Laboratory of Laser Physics and OpticsDepartment of PhysicsFudan UniversityShanghai 200433

We find that bare C_(n)^(-) clusters favor chain structure from n=4 up to 43 by laser desorption mass spectrometric study of C60 admixed with polystyrene,whereas both one-and two-dimensional structures should coexist ... 详细信息

关键词： desorption polystyrene Chain

Single electron loss in the collisions of C^(3+) and atomic hydrogen

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Chinese Physics B 2010年第9期19卷 344-348页

作者：刘会平欧阳晓平胡华四苏光辉 State Key laboratory of Multiphase Flow in Power Engineering Department of Nuclear Science and TechnologyXi'anjiaotong University

this paper studies the projectile electron loss cross sections of C^3＋ colliding with atomic hydrogen in the frame work of extended over-barrier model at intermediate velocities （25 keV/u-600 keV/u）. the electron loss is calculated in terms of the interaction between the screened target nucleus and the active projectile electron and of the interaction between projectile electron and target electron. Compared with the convergent close-coupling calculations, screening and anti-screening calculations, this model satisfactorily reproduces the experimentally obtained energy dependence of the electron-impact ionisation cross sections and the single electron loss cross sections over the energy range investigated here.

关键词： single electron loss over-barrier model

Peri-centrosomal localization of small interfering RNAs in C. elegans

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science China Life sciences 2025年

作者： Qile Jin Xuezhu Feng Minjie Hong Ke Wang Xiangyang Chen Jiewei Cheng Yan Kuang Xiaoyue Si Mingjing Xu Xinya Huang Shouhong Guang Chengming Zhu department of Obstetrics and Gynecology The First Affiliated Hospital of USTC The USTC RNA Institute Hefei National Research Center for Physical Sciences at the Microscale School of Life Sciences Division of Life Sciences and Medicine Biomedical Sciences and Health Laboratory of Anhui Province University of Science and Technology of China School of Basic Medicine Anhui Medical University

the centrosome is the microtubule-organizing center and a crucial part of cell division. Centrosomal RNAs(cnRNAs) have been reported to enable precise spatiotemporal control of gene expression during cell division in many species. Whether and how cnRNAs exist in C. elegans are unclear. Here, using the nuclear RNAi Argonaute protein NRDE-3 as a reporter, we observed potential peri-centrosome localized small interfering(si)RNAs in C. elegans. NRDE-3 was previously shown to associate with pre-mRNAs and pre-rRNAs via a process involving the presence of complementary siRNAs. We generated a GFP-NRDE-3 knock-in transgene through CRISPR/Cas9 technology and observed that NRDE-3 formed peri-centrosomal foci neighboring the tubulin protein tBB-2, other centriole proteins and pericentriolar material(PCM)components in C. elegans embryos. the peri-centrosomal accumulation of NRDE-3 depends on RNA-dependent RNA polymerase(RdRP)-synthesized 22G siRNAs and the PAZ domain of NRDE-3, which is essential for siRNA binding. Mutation of eri-1, ergo-1, or drh-3 significantly increased the percentage of pericentrosome-enriched NRDE-3. At the metaphase of the cell cycle, NRDE-3 was enriched in both the peri-centrosomal region and the spindle. Moreover, the integrity of centriole proteins and pericentriolar material(PCM) components is also required for the peri-centrosomal accumulation of NRDE-3. therefore, we concluded that siRNAs could accumulate in the pericentrosomal region in C. elegans and suggested that the peri-centrosomal region may also be a platform for RNAi-mediated gene regulation.

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