Electron Transport Behavior in a Mirror Magnetic Field and a Uniform Electric Field

1.IntroductIOnMuchefforthasbeenpaidontheresearchabouttheglowdischargeofplasma.Low--temperatureandlow-pressuregaseousglowdischargeplasmasarewidelyusedinanumberofapplications,suchasplasmachemicalvapordeposition(PCVD),plasmaetching,plasmadisplay,gaslaser,andplasmasputtering.Someexperimentalresultshaveshownthatinglowdischargeplasmatheelectrontransportbehaviorscanbecontrolledbyamagneticfield.Fukumasaet.al.[1]showedthatmagneticfieldcouldbeusedtocontroltheelectrontransportbehaviorsindischargeplasm…     

MgH分子特性和势能随外电场的变化规律

采用密度泛函B3P86方法,结合Dunning的相关一致五重基cc-PV5Z,设置不同外电场参数进行优化计算,获得MgH分子在不同外电场中的键长、偶极矩、振动频率和红外光谱强度等物理性质参数。在此基础上,采用能量高精度耦合簇CCSD(T)方法和相同的基组扫描计算单点能,获得不同外电场下的势能曲线。结果分析表明,物理性质参数和势能均随外电场的变化而变化,且外加反向电场时变化幅度更明显。考虑到外电场与分子的相互作用,本文引入偶极近似构建外电场中的势能函数模型,编制程序拟合对应的势能函数,得出拟合参数,进而计算临界离解电场参数,结果与数值计算和理论分析较一致,相对误差均在3%以内,说明构建的模型是合理可靠的。这为分析外电场中分子光谱、动力学特性和分子Stark效应冷却囚禁提供重要的理论和实验参考。     

New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure, namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively. Based on solving a multi-term electron Boltz- mann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions. The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K. These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.     

An Experimental Apparatus for Low Energy High Charge Heavy Ions to Study Collisions on Atomic Hydrogen

The design and performance of a recoil ion source system which includes a recoil ion source, atomic hydrogen thermal oven target and an electrostatic analysis system will be discussed. The recoil ion source produces low velocity highly charged ions via collisions between heavy fast pump beams from the EN tandem accelerator and target gases. Time-of-flight techniques provide initial recoil charge state separation. Collisions of the recoils with atomic hydrogen are being studied. The atomic hydrogen is provided by a thermal oven which features long life time operation and low input power requirements. Dissociation fractions of 80% are achieved for 300 watts of input power. A hemispherical electrostatic analyzer allows the final charge states of the recoil ions to be determined thereby allowing the measurement of charge exchange processes for an energy range of 100 eV/q to 5000 eV/q for the incident recoil ions.     

^99Tc^m放射性药物的分子设计（I）

介绍了Tc的理化性质和配位化学知识;简述了^99Tc^m放射性药物分子设计的常用方法：偶联法、整体法、类似物法和拼合法;并分析了^99Tc^m放射性药物的摄取、滞留机制和电性等影响分子设计的诸多因素。     

高离化态类铁、类钴、类镍等电子序列离子的能级结构

用多组态自治场方法,系统地计算了高离化态类铁电子序列ＦｅＩ～ＸｅＸＸⅨ离子３ｐ＾６３ｄ＾８、３ｐ＾５３ｄ＾９组态、类钴等电子序列ＣｏＩ～ＸｅＸＸⅧ３ｐ＾６３ｄ＾９,３ｐ＾５３ｄ＾１０,３ｐ＾６３ｄ＾８４ｐ组态、类镍等电子序列ＮｉＩ～ＸｅＸＸⅦ离子３ｐ＾６３ｄ＾９４ｓ,３ｐ＾６ｄ＾９４ｐ,３ｐ＾６３ｄ＾９４ｄ组态的能级。计算结果与实验值符合得较好。     

Piping Cracks in JPDR, (I)

In JPDR, primary coolant leaked in August 1972 through a crack in the heat affected zone between nozzle safe end of pressure vessel and pipe. And other piping systems were then investigated, and cracks were detected in two systems. Then relations between stress and cracks in the pipes were studied. Stress was analyzed by elastic theory and examined by mockup fatigue test of pipe. Initiation of cracks are not caused by stress alone, indicating the existence of other factor involved.     

New Phase Transitions in Non-Stoichiometric U3O8-x at High Temperatures, (I)

The phase equilibrium of non-stoichiometric U₃O_8-x has been studied by thermogravimetry in the range 765°≦T≦995°C and 10^?4≦Po₂≦1 atm. The results suggest the presence of six phases within U₃O_8-x the phase, separated by second (or higher) order transitions. The relative partial molar free energies, enthalpies and entropies within an each of the six phases, as well as the standard free energies, enthalpies and entropies for the phase changes are calculated and compared with previous works.     

一种测量高压气体中离子漂移速度的方法

利用脉冲X射线机作为离子触发源,用高频数字示波器记录负载电阻上的电压信号,通过曲线拟合得出离子在高压气体中的漂移速度。用该方法实测氙离子在1.5 MPa氙气中的漂移速度,结果表明,该方法可简便有效地测量高压气体中的离子漂移速度。     

Simulation of the Radial Electric Field in the Small Size Divertor Tokamak for Discharge with Neutral Beam Injection (NBI)

The radial electric field in the edge plasma of small size divertor tokamak can be simulated by B2SOLPS0.5.2D fluid transport code. The simulation provides the follow results: (1) Switching on and off the part of the parallel plasma viscosity driven by parallel ion diamagnetic heat flux (Bekheit in J. Fusion Energ 27(4), 338–345, 2008; Schneider et al. in Nucl. Fusion 41:387, 2001) and Counter-NBI plasma heating change profile of radial electric field significantly. (2) Switching on and off the parallel plasma viscosity driven by parallel ion diamagnetic heat flux leads to the radial electric field is toroidal magnetic field dependence (3) For the case of counter-NBI plasma heating, the switching on and off the current driven by part parallel plasma viscosity depends on the ion diamagnetic heat flux leads to the ion poloidal velocity is toroidal magnetic field B_T dependence. (4) The profile of the radial electric field in edge plasma of small size divertor tokamak is consistent with poloidal rotation velocity.     

Studies of Actinium (III) in Various Solutions, (I)

A solvent extraction method using a mixture of 0.1M thenoyltrifluoroacetone and 0.1M tributylphosphate in carbon tetrachloride has been developed for the separation and purification of ²²⁸Ac in ²²⁸Ra solutions. The ²²⁸Ra was first purified by a preliminary extraction cycle. The ²²⁸Ac which had accumulated int his ²²⁸Ra fraction after the purification was separated and purified by a second solvent extraction cycle. Since commercially available ²²⁸Ra solution very often contains ²²⁶Ra, the γ-radioactive decay products of the ²²⁶Ra have to be carefully removed. The ²²⁸Ac thus prepared was found to be pure enough for use as tracer.     

Coupled Reactor Kinetics, (I)

The transfer function of the two slab loading core of Argonaut is measured and analyzed by a coupling model. The measurement shows good agreement with predicted behavior. The coupling constants and subcriticality of the component reactors are obtained and compared with the values obtained from independent statical measurements.     

Dryout Heat Flux for Core Debris Bed, (I)

For gaining basic data on decay heat coolability of debris bed in the post-accident heat removal, measurement of dryout heat flux was made, with stagnant water as coolant, in a 50mm I. D. pyrex glass cylinder vessel. The fuel debris bed subjected to decay heat was simulated by steel ball particles which were inductively heated with a power supply of 20 kHz and 30 kW. The bed was made of homogeneous size particles. An emphasis was placed on the influence of system pressure and particle size. The experiment covered the ranges over the steel ball diameters of 0.3–4.0 mm and the system pressure of 0.02–0.5 MPa.

The experimental results, as a whole, agreed fairly well with the prediction based on Lipinski's 0-D model with respect to the dependence of dryout heat flux both on pressure and on particle size. In detail, however, the dryout heat flux deviates toward a lower value at a higher pressure while to a higher value for a smaller size particle bed. Comparison of the results between the free and fixed beds suggests that the deviation to the higher side will be attributed to the channeling and/or levitation.     

G(E)函数在高能γ射线剂量测量中的应用

利用蒙特卡罗方法模拟了一个Φ7.62 cm×7.62 cm的Na I(Tl)探测器的响应特性,计算了测量系统的脉冲幅度加权函数G(E),由此改善了探测器的能量响应;利用238Pu+13C源的验证实验表明,探测器对高能γ射线探测效率的实测值和计算值的相对偏差在±10%以内。在核电厂功率运行期间,测量了反应堆厂房内的γ能谱,并基于G(E)函数计算了高能γ射线的剂量。G(E)函数法与解谱方法的计算结果对比说明,将G(E)函数法应用于高能γ剂量测量是可行的。     

REDOX Decontamination Technique Development, (I)

The decontamination technique is required to have a high decontamination rate and decontamination factor, to apply to irregularly formed metallic waste, and minimize secondary waste volume for component replacement and decommissioning. The authors were developed a new decontamination technique using Ce⁴⁺ for decommissioning, which was named “REDOX decontamination technique”. This paper has investigated decontamination conditions and regeneration conditions in a non-radioactive (namely cold) fundamental test. The decontamination conditions, namely dissolution conditions for stainless steel and carbon steel were selected using simulated samples in nitric acid solutions in varying Ce⁴⁺ concentrations, HNO₃ concentration, temperatures, and linear flow rate of decontamination solutions. The regeneration conditions for decontamination reagent were selected in various electrode materials and varying electrode separation distance, anode area/cathode area ratio, current density, Ce³⁺ concentration, and HNO₃ concentration. The REDOX decontamination technique was ascertained to have a high dissolution rate and the decontamination reagent was ascertained to be regenerated effectively by electrolysis.     

Vertically Downward Two-Phase Flow, (I)

Fully developed vertically downward two-phase flow of air-water mixture was investigated on void distribution and average void fraction among the three basic flow regimes; bubbly, slug and annular flows. The annular flow further was divided into two regimes of falling film flow and annular drop flow. Test channel is in form of inverted U-tube and tests were carried out at 100 tube diameters downstream from the curved part. Distributions of local void fraction were measured by means of a conductance needle probe method and the average void fraction was obtained from numerical integration of the measured local void fraction According to the results, profiles of local void fraction in bubby and slug flows showed characteristic natures with a peak in the middle region between the center and the wall of tube The average void fraction in downward flow depended greatly on the flow regimes. Accordingly correlation for each flow regime was developed to predict the average void fraction, based on flow mechanisms and experiments. The correlations were compared with experimental results for atmospheric air-water flow and showed satisfactory agreement.