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Stabilization and volume reduction of radioactive spent ion exchange resins

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nuclear Science and Techniques 2001年第1期12卷 68-72页

作者： YE Yu-Cai YU Shao-Ning (institute of nuclear Anerpy technology, Tsinghua University, Beijing 102201) institute of nuclear Energy technology Tsinghua University

Stabilization and volume reduction Of spent radioactive ion-exchange resins (IERs) were studied. Stabilization technology includes volume reduction with wet Chemical oxidation process and immobilization of the residue into cement. Under suitable conditions, the exhaussted radioactive ion-exchange resins were dissolved successfully in a H2,O2-Fe2+/Cu2+ catalytic oxidation system (Fenton reagent). The analytical results indicated that the radioactive nuclides loaded in the resins were concentrated in decomposed solution and solid residues. The process parameters of wet chemical oxidation and solidification were also obtained. The decomposition ratios were 100% and more than 90% for canon and anion IERs respectively. The waste volume was decreased by 40% compared with that of original spent resins.

关键词：离子交换树脂水泥固化湿式化学氧化放射性废料处理

Single-pulse CARS spectra in solid propellant combustion at atmosphere pressure

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Chinese Optics Letters 2003年第7期1卷 395-397页

作者：胡志云刘晶儒张振荣关小伟黄梅生叶锡生 Northwest institute of nuclear technology Xi'an 710024

The unstable-resonator spatially enhanced detection (USED) coherent anti-stokes Raman spectroscopy (CARS) measurements of temperature and N2 concentration in the combustion of solid propellant at atmosphere pressure are reported. The USED CARS measurement system has a high spatial solution of ~ 0.1 mm in diameter and 3 mm in length, and permits instantaneous measurement at 10-Hz rate. The single-pulse N2 Q-branch CARS spectra have been obtained from the propellant combustion. The temperatures and N2 concentrations of the propellant flame at different height have been achieved by fitting the experimental data to theoretical spectra. The results indicate that the temperature is up to ~ 2500 K with N2 concentration in a range from 10% to 26%.

关键词： Atmospheric pressure Combustion Raman scattering Raman spectroscopy

Numerical simulation and design of a thermionic electron gun

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Chinese Physics C 2016年第5期40卷 92-98页

作者： M.Hoseinzade A.Nijatie A.Sadighzadeh Plasma Physics and nuclear Fusion Research School Nuclear Science and Technology Research Institute

This paper reports the simulation of an electron gun. The effects on the beam quality of some parameters on the beam quality were studied and optimal choices were identified. It gives numerical beam qualities for a common electrostatic triode gun, and the dependencies on design parameters such as electrode geometries and bias voltages to these electrodes are shown. An electron beam of diameter 5 mm with energy of 5 keV was assumed for the simulation process. Some design parameters were identified as variable parameters in the presence of space charge. These parameters are the inclination angle of emission electrode, the applied voltage to the focusing electrode, the gap width between the emission electrode and the focusing electrode and the diameter of the focusing electrode. The triode extraction system is designed and optimized by using CST software （for Particle Beam Simulations）. The physical design of the extraction system is given in this paper. From the simulation results, it is concluded that the inclination angle of the emission electrode is optimized at 22.5°, the applied voltage to the focusing electrode was optimized and found to be Vfoc =-600 V, the optimal separation distance （gap between emission electrode and focusing electrode） is 4 mm, and the optimal diameter of the emission electrode is 14 mm. Initial results for these efforts aimed at emittance improvement are also given.

关键词： electron gun electron beam trajectories beam emittance and beam diameter focusing voltage

Numerical simulation of particle sedimentation in 3D rectangular channel

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Applied Mathematics and Mechanics(English Edition) 2011年第9期32卷 1147-1158页

作者：刘马林 institute of nuclear and New Energy technology Tsinghua University

The 3D lattice Boltzmann method is used to simulate particle sedimentation in a rectangular *** results of single particle sedimentation indicate that the last position of the particle is along the center line of the channel regardless of the initial position,the particle diameter,and the particle Reynolds *** wall effect on the terminal velocity is in good agreement with experimental results *** drafting,kissing,and tumbling （DKT） process is reproduced and analyzed by simulating two-particle cluster *** effects of the diameter ratio,initial position,and wall on the DKT process are *** the two particles have equal diameter sediment in the rectangular channel,a periodical DKT process and the spiraling trajectory are *** last equilibrium configuration is obtained from the simulation *** interesting regular sedimentation phenomena are found when 49 particles fall down under gravity.

关键词： sedimentation lattice Boltzmann method particle-particle interaction

Study of latch-up immunization in bulk CMOS integrated circuits exposed to transient ionizing radiation

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Science China(Technological Sciences) 2012年第11期55卷 3242-3247页

作者： LI RuiBin CHEN Wei LIN DongSheng YANG ShanChao BAI XiaoYan WANG GuiZhen LIU Yan QI Chao MA Qiang Northwest institute of nuclear technology Xi'an 710024China

This paper presents experimental results of transient gamma irradiation effects on two kinds of *** is a two-stage circuit consisting of a bipolar power device L7805CV and a bulk complementary metal-oxide-semiconductor(CMOS) device IDT6116,the other is a two-stage circuit consisting of a bipolar power device L7805CV and the equivalent circuit of the parasitic P-N-P-N structure in bulk CMOS *** results show that the L7805CV's output interruption after transient irradiation can prevent latch-up from occurring on the second stage *** demanded minimum interruption duration to avoid latch-up varies with dose rate,and this is confirmed by the experimental results.

关键词： transient radiation' latch up dose rate bulk CMOS device

Surface-Induced Dissociation of Low Energy H_2^(+) Impact on a Carbon Surface: A Monte Carlo Simulation

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Communications in Theoretical Physics 2011年第2期55卷 315-320页

作者： Shakir Ullah A.H.Dogar A.Qayyum Physics Division Pakistan Institute of Nuclear Science and Technology

A Monte Carlo simulation based on the classical binary collision approximation is performed to investigate the interaction of W2 ions with the carbon target. The incident H2^＋ ion is characterized by its translational energy, eigenenergy and population of the vibrational state, and orientation of the ion with respect to the target surface. It is shown that experimentally determined energy resolved mass spectrum of H＋ can be nicely reproduced with the help of the proposed model. These simulations predict that translational to vibrational （T → V） energy transfer efficiency increases nonlinearly with translational energy of the incident ion. T → V energy transfer efficiency along with the initial vibrational energy of the incident H＋ ion found to play an important role in dissociation. Our simulations also show that the fraction of absorbed, reflected, and dissociated ions depends on the translational energy. The average vibrational energy of reflected H＋ increases with its initial translational energy. Moreover, average number of collisions required for dissociation varies inversely with the initial translational energy of the H2^＋.

关键词： ion-surface collisions surface-induced dissociation hydrogen molecular ions Monte Carlo simulation

On the mechanism of eutectic structure

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Progress in Natural Science:Materials International 2001年第5期11卷 27-32页

作者：程开甲程漱玉 China Northwest institute of nuclear technology Xi’an 710024

The criteria for stabilities of eutectics, solid solutions and precipitates are proposed. Based on the Thomas-Fermi-Dirac model on the boundary conditions, electron densities and chemical potentials should be equal in either side of a composite film. The optimum condition for the energy balance and the sizes of films of eutectics is given.

关键词： Thomas-Fermi-Dirac eutectics internal stress chemical potential electron density.

K-Shell Ionization of Molybdenum and Iron by Electron Bombardment

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Chinese Physics Letters 1996年第3期13卷 175-177页

作者： HE Fu-qing LONG Xian-guan PENG Xiu-feng LUO Zheng-ming AN Zhu institute of nuclear Science and technology Sichuan UniversityChengdu 610064

K-ionization cross sections of Mo and Fe by electron impact were measured by detecting characteristic x-ray emitted by thin solid Him targets of known mass thickness with a Si(Li)*** correction of a substrate was done by bipartition model of electron *** experrmenta.1 results are compared with theoretical calculation and empirical formula calculation.

关键词： calculation. correction partition

Systematic studies on α-decay half-lives for super heavy nuclei

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Chinese Physics C 2010年第3期34卷 334-339页

作者：张地大陈宝秋马中玉 School of nuclear Engineering and technology East China Institute of Technology China institute of Atomic Energy

Radioactive decay of super heavy nuclei via the emission of α-particles has been studied theoretically in the preformed cluster model （PCM）. The nucleus-nucleus （NN） potential is obtained by double folding the density distributions of the α-particle and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction, supplemented by a zero-range pseudo-potential for exchange term, is used to calculate the NN potential. The α decay half-lives for 317 nuclei at Z=102 120 are performed in the PCM framework with the theoretical Q values extracted from the MSller-Nix-Kratz and Liran-Marinov-Zeldes mass tables and are compared with the experimental data. The calculated results are also compared with those obtained by using Q values from the Muntian-Hofmann-Patyk-Sobiczewski and Myers-Swiatecki mass estimates.

关键词： preformed cluster model (PCM) α-dacay half lives super heavy nuclei mass tables