Numerical Simulation of the Discharge Efficiency in Five-electrode AC PDP

A new type of AC PDP (alternating current plasma display panel) cell with a fiveelectrode structure is developed to improve the luminous efficiency of AC PDP, The discharge efficiency of this new cell structure is investigated by a 2D fluid simulation. Continuity equations and flux density equations for charged particles and excited atoms, energy balance equation for electrons are included in the model. The discharge gas is He 5%Xe. The reactions of ionization, excitation, recombination, and radiation are taken into account. The vacuum ultraviolet radiation efficiency of the five-electrode cell structure is about 20% higher than that of a conventional three-electrode cell structure.     

The Characteristics of CLHS Driving for High Luminance Efficiency in AC PDP

This paper proposes a CLHS(Capacitor Less Half Sustain) driving method that is applied to a long gap panel to reduce the power consumption. In order to reduce the power consumption in moving images, the luminous efficiency should be improved at the low discharge load(25%). The weight of reactive power consumption tends to increase as the low discharge load decreases. Thus, it is very important to improve the luminous efficiency at low discharge load. It is well known that a long gap panel improves the luminance and the luminous efficiency but it is very difficult to drive the panel due to high driving voltage. It is confirmed that the main factors which cause a long gap panel to increase the minimum driving voltages are not only a long discharge gap but also self-erasing discharge. Self-erasing discharge is generated between the address and sustain electrodes in a sustain period. The CLHS driving method can reduce the reactive power consumption in a sustain period because energy recovery capacitors were removed in the sustain circuit. The CLHS driving method can reduce the minimum driving voltage of the long gap panel because the self-erasing discharge was prevented. When the CLHS driving method was applied to the panel with an ITO gap of 100 μm, VSand VAminimum voltages are reduced by about 9 V and 12 V compared with those of the normal driving method. The luminance and the luminous efficiency also increased by about 24.3% and 33.3% at the discharge load of 4% compared with those at the normal condition.     

三套大型交流脉冲飞轮发电机组系统的建造与运行

利用旧有的三套脉冲发电机组进行了合理的配置以及必要的技术改造,成功实现了为HL-2A装置供电并满足了物理实验的要求,同时还构成了我国当今装机容量与储能、释能规模均最大的双Y移相30°脉冲发电机组系统。     

A New Method for Measuring the Wall Charge Waveforms of AC PDP

A new method is developed to measure the wall charge waveforms in coplanar alternating current plasma display panel (AC PDP). In the method, two groups of display electrodes are selected from a coplanar AC PDP and two capacitors are respectively connected with thesetwo groups of display electrodes in series, and a measuring circuit and a reference circuit are thus constructed. With the help of special processing, discharge takes place in the cells included in the measuring circuit under a normal drive voltage but no discharge takes place in the cells included in the reference circuit under a normal drive voltage. The wall charge waveforms are obtained from the voltage difference between the two capacitors. Using the method, the wall charge waveforms are measured during resetting period, addressing period and sustaining period for the 304.8 mm (12-inch) test PDP panel. The result shows that the wall voltage is about 96 V during the sustaining period.     

双脉冲法精确测量PMT脉冲线性电流的实验设计

PMT脉冲线性电流是PMT在脉冲工作方式下的重要参数,它直接关系到实验结果的可靠性。本文对比各种测量PMT脉冲线性电流方法的优缺点,从提高测量精度方面考虑,设计了基于双脉冲法的测量PMT脉冲线性电流的实验,通过挑选稳定性高的LED作为光源,利用DG2020信号发生器给LED灯供电,采用通道循环功能加长信号时间间隔,使用分路输出到两台示波器接收信号,应用示波器多次采集自动取平均的功能等方法在实验细节上进行设计,提高测量精度。通过实验测到了PMT脉冲输出电流偏离线性直线1%处的电流,并获得了PMT脉冲输出的mA级至A级电流全曲线。     

Operation Mode on Pulse Modulation in Atmospheric Radio Frequency Glow Discharges

The discharge operation regime of pulse modulated atmospheric radio frequency(RF) glow discharge in helium is investigated on the duty cycle and frequency of modulation pulses.The characteristics of radio frequency discharge burst in terms of breakdown voltage, alpha(α)-gamma(γ) mode transition voltage and current are demonstrated by the discharge current voltage characteristics. The minimum breakdown voltage of RF discharge burst was obtained at the duty cycle of 20% and frequency of 400 k Hz, respectively. The α-γ mode transition of RF discharge burst occurs at higher voltage and current by reducing the duty cycle and elevating the modulation frequency before the RF discharge burst evolving into the ignition phase, in which the RF discharge burst can operate stably in the γ mode. It proposes that the intensity and stability of RF discharge burst can be improved by manipulating the duty cycle and modulation frequency in pulse modulated atmospheric RF glow discharge.     

脉冲反应堆脉冲运行瞬态的子通道分析

为获得脉冲运行瞬态的堆芯温度场变化情况,本文开发了适用于低温、常压工况的脉冲反应堆瞬态热工分析子通道程序PRC-STAC。利用TRIGA MARKⅡ反应堆的瞬态参数对程序进行了验证,验证结果表明,二者符合较好。利用PRC-STAC程序计算了西安脉冲堆燃料元件和堆芯冷却剂的瞬态热工参数,并讨论了脉冲运行对燃料元件的安全影响。     

Long Pulse Operation of High Performance Plasmas in JT-60U

Recent experimental progress in JT-60U advanced tokamak research is presented： sustainment of the normalized beta （βN）- 3 in a normal magnetic shear plasma, the bootstrap current fraction （fBs） - 45% in a weak shear plasma and - 75% in a reversed magnetic shear plasma in a nearly fully non-inductive current drive condition for longer than the current relaxation time. Achievement of high-density, high-radiation fraction together with high-confinement in advanced plasmas is demonstrated. Achievements and findings in long pulse operations after system modification are presented as well. A 65 s discharge of Ip = 0.7 MA was successfully obtained. As a result, high-βN of 2.3 was successfully sustained for a very long period of 22.3 s. In addition, a 30 s standard ELMy H-mode plasma of Ip up to 1.4 MA was also obtained. Effectiveness of divertor pumping to control particle recycling and the electron density under the saturated wall retention was demonstrated. These achievements and issues in development are discussed.     

Study of the DEF Feedback Control System in AC Operation of Superconducting Tokamak

AC operation with multiple full cycles has been successfully performed on the superconducting tokamak HT-7. In the experiment, it was discovered that the saturation of the transformer magnetic flux with DEF, a signal name, was one of key aspects that affected the AC operation. The conditions of DEF were examined through the DEF feedback control system. By controlling the working patterns of the subsystems, namely the poloidal field control system and density control system, it was guaranteed that DEF would remain in the non-saturated status.     

脉冲堆稳态堆芯脉冲运行实验研究

对脉冲堆进行稳态堆芯脉冲运行实验,并对实验结果进行了分析.分析结果表明,在西安脉冲堆原设计的稳态堆芯布置方式下进行脉冲运行是安全可行的.通过实验,获得了脉冲堆稳态堆芯脉冲运行的相关参数,并与理论计算结果进行了比对,分析了二者的偏差.     

MOS器件脉冲总剂量效应时间关联晌应的模拟计算

本文建立了MOS器件脉冲总剂量效应时间关联响应的计算模型,包括空穴输运引起的短期恢复、深层俘获空穴引起的长期恢复以及界面态的长期建立,详细讨论了俘获空穴空间分布的差异对退火响应的影响以及温度差异对界面态建立的影响.计算结果和试验测量值符合较好,表明建立的计算模型是正确的.     

Near-Resonant Effects on Propagation of Frequency-Swept Laser Pulse in Atomic Vapor Laser Isotope Separation

The propagation characteristics of frequency-swept laser pulse in near-resonant medium were studied by the numerical calculation and the experiment. The characteristics of the frequency-swept laser pulse has been largely modified in comparison with the frequency-fixed laser pulse. These modifications were demonstrated also experimentally for Sm vapor. The results agreed well with the numerically calculated.     

高功率脉冲微波细胞生物效应中脉冲个数与效应的关系研究

研究了不同脉冲个数的2.71 GHz和9.33 GHz脉冲微波作用于IAR20鼠肝细胞和L-02人肝细胞所导致细胞增殖变化的生物效应,并对实验结果进行分析,通过拟合得到了脉冲个数与脉冲微波非热生物效应之间的剂量效应关系。在本实验范围内,脉冲微波辐照细胞后,细胞增殖率随脉冲个数的增加而呈近似e指数衰减规律,并且在脉冲个数达到一定值时,趋向饱和。     

Reactor and Linear Accelerator Induced Effects in Dielectrics

The currents induced by nuclear radiation from a pulsed reactor on several commercial capacitors are compared with those induced by the electron beam of a linear accelerator (LINAC) source. Dependence of the radiation induced current on applied voltage, geometry, dose, and dose rate is contrasted for Mylar*, polystyrene, mica, tantalum, glass, and ceramic capacitors. These effects are analyzed in terms of models appropriate for the various capacitors, and values of parameters defining these relationships are given. The relative effectiveness of neutron and gamma radiation in producing induced currents in these capacitive elements at the reactor environment was also obtained.     

Criterion of Magnetic Saturation and Simulation of Nonlinear Magnetization for a Linear Multi-core Pulse Transformer

The linear multi-core pulse transformer is an important primary driving source used in pulsed power apparatus for the production of dense plasma owing to its compact,relatively low-cost and easy-to-handle characteristics.The evaluation of the magnetic saturation of the transformer cores is essential to the transformer design,because the energy transfer efficiency of the transformer will degrade significantly after magnetic saturation.This work propses analytical formulas of the criterion of magnetic saturation for the cores when the transformer driver practical loads.Furthermore,an electric circuit model based on a dependent source treatment for simulating the electric behavior of the cores related to their nonlinear magnetization is developed using the initial magnetization curve of the cores.The numerical simulation with the model is used to evaluate the validity of the criterion.Both the criterion and the model are found to be in agreement with the experimental data.     

Frequency of Undulations on a Falling Water Film

An experimental study has been undertaken on the frequency of presented by the undulations occurring on the surface of a falling liquid film. The configuration of the film surface was observed by measuring the changes in the film thickness by means of a capacitometer. The flow regime was in the range of turbulent flow region, in which the undulations occur prominently and travel down along with the fluid film. The undulations proceed downward in an almost fixed pattern. The frequency of the passage of crests observed from a fixed point was evaluated from power spectral analysis to be about 20–30Hz, and this value changed very little with the Reynolds number and with heat flux applied to the falling liquid film. It is shown that this constancy of observed frequency is related to the fact that the large undulations move at the same velocity as the bulk of the fluid film, and that the speed of propagation is corresponding to a group velocity for ripples on the film surface.     

Investigation of Anode Striation in 34＂ VGA Shadow Mask PDP

A macro-cell was used to study the phenomenon of anode striation on a 34 VGA Shadow Mask Plasma Display Panel （SMPDP）. The breakdown process in the sustaining period of the macro-cell was taken by an Intensified Charge Coupled Device（ICCD） with narrow band filters. The mechanism of formation and evolution of the anode striation on SMPDP were investigated. The influence of the width of the electrode, the sustaining voltage, sustaining frequency and the voltage of the shadow mask on the anode striation was also studied. The results showed that the width of the electrodes, the sustaining voltage and frequency had a strong influence on the anode striation. The voltage of the shadow mask, however, hardly affected the anode striation, the firing voltage or the sustaining voltage.     

SEM Analysis of Ionizing Radiation Effects in Linear Integrated Circuits

A successful diagnostic technique was developed using a scanning electron microscope (SEM) as a precision tool to determine ionization effects in integrated circuits. Previous SEM methods radiated the entire semiconductor chip or major areas. The large area exposure methods do not reveal the exact components which are sensitive to radiation. To locate these sensitive components a new method was developed, which consisted in successively irradiating selected components on the device chip with equal doses of electrons [(10 rad (Si)], while the whole device was subjected to representative bias conditions. A suitable device parameter was measured in situ after each successive irradiation with the beam off.     

Progress of Research on Fuel Element Behavior at Power Ramp Test

Researchonfuelelementbehavioratpowerramptestisakeyprojectofhighperfor-mancefuelassemblyresearchprogram.Atpresent,thepreparationworkforin-piletesthasbeencompletedandthemainprogressisasfollows.1)IrradiationtechniqueThein-pilemeasurementofabsorbingabilityoft…     

CPR1000核电机组换料后再启动升功率策略优化研究

根据大量核电厂运行经验反馈和模拟计算分析,中国改进型三环路压水堆（CPR1000）核电机组采用的升功率技术限值仍有较大优化空间。本文从升功率速率和阈值功率水平2个角度对换料后反应堆再启动以及达到满功率后运行模式进行模拟,升功率过程至达到满功率后一般经历几十个小时后燃料棒就能达到参考状态,采用优化升功率速率可以将能力因子提升0.1%左右。