Driver of THz-FELs based on the YerPhI 20 MeV linear accelerator

An opportunity of using the 20 MeV Linac at YerPhI as a driver of THz-FELs is considered. The basic parameters of the Linac and FELs are given. Requirements to the electron beam and Linac systems are determined.     

在时域和频域控制下色散管理孤子系统的定时抖动

利用变分法研究了时域和频域的控制技术同步幅度调制器和固定频率滤波器对色散管理孤子系统的作用.得到了计算定时抖动的解析表达式,利用得到的公式,可以计算不同控制参量时,孤子系统定时抖动的大小,从而优化同步幅度调制器和固定频率滤波器的设计.结果也证明了滤波器对喇曼效应引起的时间抖动的抑制作用.     

DVB传输流捕获系统的实现

研究了DVB传输流实时捕获系统的结构及其实现方法．该系统的硬件利用复杂可编程逻辑器件和总线接口芯片,实现了传输流与PcI总线之间的接口,软件利用设备驱动程序将硬件采集的数据流传入计算机．同时保证了高速的数据交换速率,可以对捕获的数据流进行实时的处理,该系统在DvB的分析、测试、存储、编辑和复用中都有着广阔的应用前景．     

Probability analysis of position errors using uncooled IR stereo camera

This paper analyzes the random phenomenon of 3D positions when tracking moving objects using the infrared (IR) stereo camera, and proposes a probability model of 3D positions. The proposed probability model integrates two random error phenomena. One is the pixel quantization error which is caused by discrete sampling pixels in estimating disparity values of stereo camera. The other is the timing jitter which results from the irregular acquisition-timing in the uncooled IR cameras. This paper derives a probability distribution function by combining jitter model with pixel quantization error. To verify the proposed probability function of 3D positions, the experiments on tracking fast moving objects are performed using IR stereo camera system. The 3D depths of moving object are estimated by stereo matching, and be compared with the ground truth obtained by laser scanner system. According to the experiments, the 3D depths of moving object are estimated within the statistically reliable range which is well derived by the proposed probability distribution. It is expected that the proposed probability model of 3D positions can be applied to various IR stereo camera systems that deal with fast moving objects.     

模拟退火算法优化设计钕玻璃放大器氙灯抽运

氙灯提供的有效抽运能量决定了钕玻璃中反转粒子的数目。针对氙灯供能的要求,建立了氙灯放电回路与氙灯辐射数值模型。将数值模拟结果与实验结果进行了比对,提出了利用模拟退火算法求解最优抽运状态的电路参数的方法,并模拟计算不同电路参数下氙灯的工作状态。定义了两个更实用的评价参数:有效辐射效率和有效输出光谱效率,用于筛选最佳的抽运能量和进灯功率。计算结果表明,在氙灯参数与工作电压一定的条件下,通过利用模拟退火算法可以快速优化放电回路中的电容、电感参数,以选择最佳的进灯能量,避免抽运带内有效能量份额因光谱蓝移而降低,同时可保证氙灯的使用寿命。     

Through-silicon-via crosstalk model and optimization design for three-dimensional integrated circuits

Through-silicon-via （TSV） to TSV crosstalk noise is one of the key factors affecting the signal integrity of three- dimensional integrated circuits （3D ICs）. Based on the frequency dependent equivalent electrical parameters for the TSV channel, an analytical crosstalk noise model is established to capture the TSV induced crosstalk noise. The impact of various design parameters including insulation dielectric, via pitch, via height, silicon conductivity, and terminal impedance on the crosstalk noise is analyzed with the proposed model. Two approaches are proposed to alleviate the TSV noise, namely, driver sizing and via shielding, and the SPICE results show 241 rnV and 379 mV reductions in the peak noise voltage, respectively.     

LTD模块气体开关电极材料烧蚀性能实验

针对直线变压器驱动源(LTD)对开关的长寿命需求,基于前期研制的200kV低抖动多间隙气体开关电极几何参数以及开关通流水平,详细开展了不同电极材料(钼、黄铜、铜钨合金、高密度石墨、304和321不锈钢)的烧蚀性能实验。实验结果表明,在单次电荷转移量15.4mC,脉冲电流20kA条件下,体积烧蚀速率从大到小依次为:石墨、黄铜、铜钨合金、钼、不锈钢。电极烧蚀微观形貌分析表明,不锈钢是用于LTD开关相对较好的电极材料。根据不锈钢电极的体积烧蚀速率,可知理论上LTD开关的运行寿命可以超过1×106次,但前提是开关外壳需保持足够的绝缘强度。     

Vector solitons in a laser passively mode-locked by single-wall carbon nanotubes

Polarization Rotation Locked Vector Solitons (PRLVSs) are experimentally observed for the first time in a fiber ring laser passively mode-locked by a single-wall carbon nanotube (SWCNT) saturable absorber. Period-doubling of these solitons at certain birefringence values has also been observed. We show that fine adjustment to the intracavity birefringence can swing the PRLVSs from period-doubled to period-one state without simultaneous reduction in the pump strength. The timing jitter for both states has also been measured experimentally and discussed analytically using the theoretical framework provided by the Haus model.     

Simulative analysis of soliton-based DPSK transmission system

The effectiveness of the conventional dispersion compensation techniques: DCF, FBG and OPC to use with soliton transmission is presented. The frequency shifts of solitons induced by collisions between different channels in a soliton WDM system can be reduced by dispersion compensation. The reduction mechanism applied is the cancellation of the shifts generated in both normal and anomalous dispersion regimes. It is analyzed that phase jitter can be reduced by the use of midway spectral inversion.     

基于PCI-E总线的北斗导航授时卡Linux驱动设计

为提高Linux系统时间的精确度,设计了PCI-Express接口的北斗授时卡以及驱动程序。简要介绍了授时卡硬件和Linux系统设备驱动程序设计,包括驱动的编译、加载,同时利用图形界面开发工具GTK 编写授时测试软件。试验结果证明：在Ubuntu kylin系统平台下授时测试软件运行稳定、界面简洁,且授时精度达到100纳秒。