基于CORBA的聚龙一号装置控制系统的研制

建成的聚龙一号装置PTS由24个基于Marx发生器和水线的性能、结构相同的模块组成,运行控制节点众多,控制规模大,试验过程复杂。根据分布式对象技术CORBA的技术特点,介绍了基于CORBA的聚龙一号装置控制系统的研制,重点分析了聚龙一号装置控制系统框架和结构及CORBA技术的应用。目前该控制系统已稳定运行1年,为聚龙一号装置提供了安全有效的运行及维护服务,对于即将开展的X射线自由电子激光装置等大型物理实验装置控制系统的总体设计具有一定的参考价值和意义。     

基于CORBA的聚龙一号装置控制系统的研制

建成的聚龙一号装置PTS由24个基于Marx发生器和水线的性能、结构相同的模块组成,运行控制节点众多,控制规模大,试验过程复杂。根据分布式对象技术CORBA的技术特点,介绍了基于CORBA的聚龙一号装置控制系统的研制,重点分析了聚龙一号装置控制系统框架和结构及CORBA技术的应用。目前该控制系统已稳定运行1年,为聚龙一号装置提供了安全有效的运行及维护服务,对于即将开展的X射线自由电子激光装置等大型物理实验装置控制系统的总体设计具有一定的参考价值和意义。     

软X射线层析摄影在HL—1装置上的应用

本文描述我们建立的含有22道探测器阵列及数据采集和处理系统的软X射线层析摄影诊断,并成功地应用于HL-1托卡马克装置,获得了软X射线辐射的二维层析图的时间分辨,初步观察了等离子体MHD不稳定性发展变化的局部过程。     

Features in atomic force microscopy studies of dielectric surfaces

To improve the accuracy of AFM measurements in air and the reproducibility of results, a clean room-based metrological facility has been designed and built. The main function of the facility is to control temperature and humidity in an operation zone in various combinations and to maintain them with high accuracy. Measurements under controlled conditions are particularly important for dielectric materials. It has been shown that special procedures allow one to avoid disturbances caused by static charges on the surface under study, i.e., to remove the already accumulated charge and prevent its appearance during experiments. The use of the proposed procedures makes it possible to adequately study the features of the dielectric surface relief at micro-and nanoscale levels.     

HL-2A的中央逻辑控制PLC环网设计

PLC逻辑控制是HL-2A中央控制系统的重要组成部分,改造前的逻辑控制系统基本使用硬连接,维护耗时耗力。结合新一代实时工业以太网PROFINET为HL-2A逻辑控制系统的改造设计了环形冗余网络。采用8台西门子交换机SCALANCE X200通过光纤依次连接成环,交换机的电口连接S7-400和上位机,与等离子体放电相关的重要信号仍走硬连接,其他所有信号都走网络传送。中控系统作为管理站对其他7个子系统进行集中化管理,中控可以轻松快速地获取每个子系统的状态,在等离子体放电错误时能很快的预测事故地点和故障分析。根据放电实验结果表明,光纤环网非常适用于设备分散的慢控制系统,整个控制系统逻辑关系清楚,后期扩展和改造也非常方便。改造后的逻辑控制系统能满足HL-2A和HL-2M两套装置的慢控制,维护简便,事故定位快准,提高了放电效率。     

弹跳运动的Simulink仿真模拟

本文建立了小球在谐振桌面上做弹跳运动的动力学模型,并用Simulink仿真软件模拟了小球在不同参数下从规则运动到无规则运动的各种动力学行为,仿真的结果表明,控制参数对系统的动力学行为有重要的影响.     

Simulation and experiment of a YBCO SMES prototype in voltage sag compensation

This paper gives a introduction of a SMES unit using 2G HTS wires. A complete SMES system including both superconducting coils and control circuit has been designed to operate at 77 K. Three single-phase H-bridge converters have been used in the control circuit. A loop control signal is sent out by using 32 fixed point Digital Signal Processor (DSP). The complete circuit has been both modelled in simulation and built experimentally. The results validate that this SMES successfully compensates a voltage sag in a power system.     

光擦除双光束耦合的阈值开关特性

基于光擦除折射率光栅和双光束耦合构成了一种新型的非线性光学器件.用带导模型和耦合波方程建立了理论公式.用KNSBN单晶和Ar~+激光进行了实验演示.理论和实验都表明该器件具有明显的阈值开关特性.     

An externally cooled beetle type scanning tunneling microscope for imaging in cryogenic liquids

We describe a variable temperature cryogenic scanning tunneling microscope designed for imaging and research in cryogenic liquids. It has an external Dewar type large scale cooling system with a temperature control range of roughly 85-110 K using pressure controlled liquid nitrogen cooling. The liquid nitrogen is kept in a closed chamber surrounding the STM and maintained at a pressure to suit the chosen temperature. Several gases have triple points in this temperature range and can therefore be liquified, such as argon, methane, silane and germane. The STM is based on a beetle type design built into a small cube vacuum chamber to fit into the cooling dewar. The system has been used for atomic resolution of highly oriented graphite submerged in a methane liquid at a temperature of 100 K.     

基于DSP的高功率TEACO2激光器控制系统的高精度数据采集

针对基于DSP的高功率TEA CO2激光器控制系统直接利用DSP F2812内置A/D转换器（ADC）进行模拟量采样时存在转换误差较大,且模拟量易受电磁干扰等问题,从硬件和软件两个角度提出了校正DSP2812内置ADC的方法。硬件上采用硬件模拟滤波和隔离等手段对输入的模拟量进行处理;软件校正则通过将两路给定的参考电压值送入DSPF2812内置A/D转换器的两个转换通道,计算出ADC的偏置误差和增益误差,以此误差对其它通道A/D转换器进行校正。最后,实验分析了参考电压和A/D采样时钟频率对A/D转换精度的影响。结果表明,提出的方法能有效地提高A/D转换器的精度,A/D转换误差达到±3 LSB,特别是在对腔压值精度要求很高的0～12 000 Pa区段,A/D转换精度达±1 LSB,可以保证TEA CO2激光器的可靠运行。     

Test of the LHAASO electron detector prototype using cosmic rays

The LHAASO project is to be built in south-west China, using an array of 5137 electron detectors for the measurement of incident electrons arriving at the detector plane. For quality control of the large number of electron detectors, a cosmic ray hodoscope with two-dimensional spatial sensitivity and good time resolution has been developed. The first prototype of the electron detector has been tested with the hodoscope and the performance of the detector is found to be consistent with the design.     

Reference reflection cavity for the far infrared1

A simple non-resonant cavity system has been built and tested for use in the far-i.r. (4–700 cm⁻¹). It allows for detection of small percentage changes in sample reflectivity by use of a matched reference cavity.     

薄膜光栅耦合器的研究

在玻璃衬底上制备了周期为0.56μm的薄膜光栅耦合器,用复制法把光栅做在玻璃衬底上。实验中,我们观察到,激光束既可以从光栅的上面(空气区)或下面(衬底区)耦合于波导薄膜内,又可以通过光栅由波导薄膜中耦合出来。调节激光束入射角可以激发不同阶的波导模式。由实验测得的输入耦合效率达66.0±0.5％。 关键词：     

激光系统组件化仿真软件EasyLaser

针对国内一直以来缺乏一套能够对复杂激光系统进行全面仿真模拟工具的问题,在成熟仿真模块的基础上,基于组件化建模仿真思想研发了通用易用的激光系统仿真软件EasyLaser。它由通用的组件化建模仿真支撑平台SciSimu和8个仿真组件库构成,具备对光束的光学元件间传输、大气传输、电视成像、自适应光学校正、识别提取跟踪等复杂过程的建模与仿真能力。详细介绍了EasyLaser的物理仿真能力和软件特色,并利用EasyLaser软件搭建仿真光路模型,进行自适应光学系统对大气湍流效应的校正效果的分析和研究。     

New approach to non-perturbative physics

It was shown that the non-perturbative properties of the vacuum are described by the quantum fluctuations around the classical background with zero canonical momentum. The vacuum state has been built and checked in the framework of the sigma models in two dimensions.     

Measurement and study of the embedding impedance presented by the whisker antenna of a schottky diode corner cube mixer

A 250× scale model of a Schottky diode corner cube mixer designed for operation in the terahertz region has been built and tested. It has been successfully used to measure the embedding impedance presented to the diode at the whisker tip and also determine the impedance of the whisker antenna itself. The results have been input into a computer analysis to determine as to how the performance may be improved. With regards to improving the physical ruggedness of such mixers, a simple equivalent whisker structure has been determined and a new technique that may be used to fabricate a space qualifiable corner cube mixer intended for terahertz operation is disclosed.     

RIKEN-BNL Research Center

RIKEN-BNL Research Center came into existence in the fall of 1997. It is dedicated to the strong interaction physics and aims at promoting young researchers. It has been leading the RHIC and RHIC-Spin researches, revolutionized the cascade models for relativistic heavy-ion collisions, built the world's fastest non-commercial supercomputer, and is pioneering the lattice-QCD numerical calculations with exact chiral symmetry.     

Stimuli-responsive self-assembled multilayer azo thin films: Photo-switchable absorbance and morphological characteristics

Light has been employed as a source of energy for surface modulation, tuning and control in photo-responsive azo-incorporating self-assembled polyelectrolyte multilayer thin films. A custom built setup for controlled exposure enabled successful photo-switching. Spectral changes were characterized through UV–vis spectroscopy, while scanning electron microscopy technique was employed to study structural properties and response of the films. The effects of chromophore aggregation and dispersion on thin film photo-responsiveness have been studied, with significant contributions made to a recently proposed model correlating structural and spectral properties of the azo thin films. Structural and optical photo-responses have been acquired for surface tuning and modulation, while photo-reversibility is also achieved to control surface properties cyclically.     

Optical focus control system for laser welding and direct casting

A non-intrusive optical sensor system has been developed for focus control of laser welding. This detects the light generated by the process through the laser delivery optics, and exploits the chromatic aberrations of these optics to detect any laser focal error at the workpiece. This system works for a wide range of materials and welding parameters, and example results are presented. The sensor has also been applied to laser ‘direct casting’, a process in which 3-D structures are built by flowing metal powder into a focused laser beam. In this case, melt pool temperature is also important, and so additional optics are incorporated into the sensor to provide a pyrometric temperature measurement which is used to control the laser power.     

Timing system of HIRFL-CSR

The national science project HIRFL-CSR has recently been officially accepted. As a cyclotron and synchrotron complex, it puts some particularly high demands on the control system. There are hundreds of pieces of equipment that need to be synchronized. An integrated timing control system is built to meet these demands. The output rate and the accuracy of the controller are 16 bit/tzs. The accuracy of the time delay reaches 40 ns. The timing control system is based on a typical event distribution system, which adopts the new event generation and the distribution scheme. The scheme of the timing control system with innovation points, the architecture and the implemented method are presented in the paper.