便携式双通道多道核谱仪中数据采集系统的设计

介绍应用FPGA为核心芯片配合峰保电路、高速A／D转换电路以及USB接口电路实现了便携式双通道多道核谱仪中数据采集系统；给出了软硬件的实现方案和实验结果；该系统具有采集精度高、传输快等特点，同时为进一步实现多通道信号采集提供了很好的参考价值。     

重离子束探针诊断的发展（上）

本文报告在最近几年里库尔恰托夫和莫斯科重离子束探针（ＨＩＢＰ）组的工作结果。概括叙述了在前苏联已发表的论文并摘录了一些未发表的报告。全文回顾了包括实验的规划与设计问题以及对决定等离子体密度和电流的实验数据分析问题的诊断的数学基础；说明了用于测量等离子体电势与密度的实验探测装置结果；讨论了一些测量结果以及提到了在现代研究工作中扩大ＨＩＢＰ应用的趋势。     

基于USB和FPGA的多功能数据采集系统

设计并实现了一种基于USB接口的多功能数据采集系统。该系统支持4路模拟信号输入,通过高速ADC进行采样,数字化后的数据由FPGA进行处理,可实现波形采样、脉冲计数、多道脉冲幅度分析、电荷分配法信号读出等功能。下位机硬件和PC通过USB接口通信,上位机软件采用Labview编写,负责初始化硬件以及参数配置,读取采集数据并进行数据在线处理以及结果的实时显示。     

等离子体纳米探针在细胞成像中的应用

贵金属纳米材料具有局域表面等离子共振效应,由于其独特的物理、化学和光学性质,在纳米光子学、化学传感、靶向放射治疗、生物成像等领域得到日益广泛的应用。通过调控等离子体纳米颗粒的组成、形貌和尺寸,可以得到性质各异的散射光探针,并利用暗场显微镜对其进行观测。与荧光探针相比,等离子体纳米探针具有灵敏、稳定的优势,适合活细胞成像和对单个探针进行实时追踪。本文介绍了适用于暗场显微成像的等离子体纳米探针的最新进展;总结了其在观测细胞膜受体分布、原位检测细胞内各类生物分子、追踪胞内转运过程等方面的应用;并对暗场细胞成像的前景进行了展望。     

USB2.0通讯在数据采集系统中的应用

设计USB数据采集系统的难点在于:其一,对USB传输、事务、信息包以及握手信号等相关概念的正确理解和应用;其二,正确处理好数据采集与数据传输之间的时序关系。针对一种实际的数据采集系统的设计特点,对设计过程进行了较详细的阐述。     

Optimization of Langmuir Probe System Parameters in a Stationary Laboratory Plasma

In order to obtain creditable data an applicable method to optimize parameters of the Langmuir probes and circuits in a stationary laboratory device is investigated and an experimental criterion of the probe dimension is developed. To obtain the electron temperature and density the Electron Energy Distribution Function （EEDF） approach with less computing time and more accurate results is applied, instead of the conventional slope approach. Moreover the influence of the vessel wall materials on the plasma density is discussed briefly, indicating that the dielectric wall is helpful to enhancing the electron density.     

便携式核材料中子测量系统的研制

研制了小型中子探测系统，并进行了性能测试和应用研究。系统主要由屏蔽式中子探头、中子分析仪和控制微机（数据获取软件）组成，体积小、质量轻、性能稳定、自动化程度高，能进行长期自动测量。该系统可广泛应用于核保障领域核材料的非破坏性分析（NDA），特别适合核材料现场核实测量。     

Langmuir Probe Measurements of an Expanding Argon Plasma

In this work,we studied the effects of the discharge current,gas flow rate and vessel pressure on the electron temperature and density of Ar plasma by Langmuir probe measurement.The argon plasma was created by a one-cathode arc source.The experimental results show that with increasing discharge current and gas flow rate,the electron temperature and density increase.It is found that when the discharge current is 70 A,90 A and HO A at an argon flow rate of2000 seem,the electron densities at about 0.186 m distance from the nozzle are 13.00×10~(18) m~(-3),14.04×10~(18) m~(-3) and 15.62×10~(18) m~(-3),and the electron temperatures are 0.38 eV,0.58 eV and0.71 eV,respectively.The positive I-V characteristic is explained.     

SSRF-X射线小角散射实验站数据采集系统

采用LabVIEW对上海光源(SSRF)X射线小角散射(SAXS)实验站数据采集系统进行了设计,实现了对气体探测器和电离室的电子学系统实验参数设置、实验数据采集和实验结果的保存功能.经实验测试,证实了该系统的正确性和完整性.     

Sweep Langmuir Probe and Triple Probe Diagnostics for Transient Plasma Produced by Hypervelocity Impact

Two techniques are applied to diagnose characteristic parameters of plasma created by hypervelocity impact, such as electron temperature and electron density. The first technique is a sweep Langmuir probe （SLP）, which is a new apparatus based on a dual channel circuit that can compensate for stray capacitance and obtain a good synchronicity, so that electrostatic turbulence with a good temporal resolution can be acquired. The second technique is a triple Langmuir probe （TLP）, which is an electrostatic triple Langmuir probe diagnostic system, in which no voltage and frequency sweep is required. This technique allows to measure electron temperature, electron density as a function of time. Moreover, the triple Langmuir probe diagnostic system allows the direct display of electron temperature and semidirect display of electron density by an appropriate display system, the system permits us to eliminate almost all data processing procedures. SLP and TLP were applied to obtain fluctuations of the characteristic parameters of plasma generated by hypervelocity impact. As an example of their application to time-dependent plasma measure- ment, the electron temperature and electron density of plasmas were acquired in hypervelocity impact experiments. Characteristic parameters of plasma generated by hypervelocity impact were compared by the two kinds of diagnostic techniques mentioned above.     

Measurement of Zonal Flows in a Tokamak Using Langmuir Probe Array

Zonal flows have been measured with several novel Langmuir probe array on the HT-7 tokamak since 2002. The forked probe and its improved generation, the farmer forked probe were designed based on the original idea of the Reynolds stress triple tips array. In order to measure the radial shearing rate of zonal flows, the pyramid probe was also designed. This paper addresses the technical aspects regarding this new application. Since the zonal flows dynamics is now widely believed crucial to plasma confinement physics, an important application field of Langmuir probe was opened up.     

Characteristics of Langmuir Probe in Low Temperature, Weakly Magnetized Plasmas

The systematic Langmuir probe measurements for a weakly magnetized plasma have been carried out in the Linear Magnetized Plasma Device for different magnetic fields. By comparing the ion current density of probes with different sizes, the sheath thickness can be evaluated. It is found that while the ratio of cylindrical probe‘s dimension to ion Larmor radius is not more than 2, the model of probe for non-magnetized plasma is still applicable.     

Investigation of Arc Regulation of Hot Cathode Ion Source with Langmuir Probe

The neutral beam injector (NBI) is one of the main plasma heating methods for nuclear fusion devices. For the hot cathode high current ion source, the arc current and beam current tends to increase during the beam pulse. In order to gets long pulse beam extraction, the arc regulation technology is employed. The Langmuir probes are installed on the experimental advanced superconducting tokamak-NBI ion source, to feedback control the arc discharge and beam extraction. The experimental results show that, the long pulse of 100 s ion beam is extracted with beam energy of 30 keV with arc regulation. More the results are presented in this paper.     

BELLE物理实验DAQ系统中的精确时序调整

介绍了一个基于ＥＣＬｉｎＰＳ电路产生高精度程控延时脉冲信号的ＶＭＥ插件,该插件将用于ＢＥＬＬＥ物理实验ＤＡＱ系统中的精确时序调整,产生分辨率为１０ｎｓ的时序控制符号,其时间抖动的均方根值小于１００ｐｓ。