激光等离子体X射线椭圆弯晶谱仪的设计

为了诊断0．2～2nm的激光等离子体X射线．研制了一种新型的基于时间分辨和空间分辨的聚焦型椭圆弯晶谱仪．采用两个完全相同且对称分布的通道可以同时获得谱线的空间和时间分辨率。给出了弯品谱仪的设计参数，采用了新颖的瞄准对中技术．并对光源偏离椭圆轴线造成的误差进行了分析。在“神光Ⅱ”靶室上进行打靶实验对该谱仪进行标定，利用X射线CCD相机成功地获取了谱线的图像．实验结果表明实测谱线波长与理论值吻合。     

实现激光等离子体X射线诊断的椭圆弯晶谱仪研究

按照布拉格衍射的基本原理,利用从一个焦点发出的光线经过椭圆面反射后汇聚于另一个焦点的特点,研制了双通道椭圆弯晶谱仪,分析出其测量的波长范围为0.2nm至2nm,布拉格角的覆盖范围是30°至67.5°。并阐明弯晶分析器的制作过程。在＂星光-Ⅱ＂激光装置上对分别使用LiF、PET、KAP和Mica四种弯晶分析器的双通道椭圆弯晶谱仪进行激光打靶实验,得到了铝、钛和金激光等离子体X射线的发射谱。     

弯晶谱仪在X射线探测中的应用

为了对激光等离子体进行诊断,研制了聚焦型椭圆弯晶谱仪用来探测等离子体辐射的X射线.谱仪利用从椭圆一个焦点发射出的光线经椭圆面反射必汇聚于另一焦点的性质而研制,椭圆的离心率和焦距分别为0.9586mm及1350mm.在此采用氟化锂(200)(2d=0.4027nm)作为晶体分析器,其布拉格衍射角变化范围为30～67.5°,可探测波长范嗣为0.2～O.37nm.在"神光-Ⅱ"激光装置上进行了打靶实验,利用软X射线CCD相机作为摄谱器件,该谱仪获得了钛的类He共振线(w)、磁四级M2跃迁x线、互组合跃迁y线、禁戒谱线(z)以及类Li谱线(q).实验结果表明该谱仪的最高光谱分辨率(λ/△λ)可以达到1000以上,能够用于激光等离子体X射线光谱学研究.     

Z箍缩等离子体X射线椭圆弯晶谱仪

为了测量Z箍缩等离子体X射线的空间分辨光谱,利用椭圆聚焦原理,研制了一种椭圆晶体谱仪.以Si(111)椭圆弯晶作为色散分析元件,椭圆的离心率为0.9480,焦距为1348 mm,布拉格角范围为30°～54°,谱线探测角范围为54°～103°,探测的波长范围为0.31～0.51 nm.设计了半径为50 mm的半圆型胶片暗盒,内装胶片接收光谱信号.分析了椭圆的弥散度对光谱分辨率的影响.在"阳"加速器装置上进行摄谱实验,胶片成功获取了氩喷气等离子体X射线的跃迁光谱,实测谱线分辨率(λ/Δλ)达300～500,波长与理论值吻合.     

电子探针特征X射线谱线识别的方法研究

特征X射线是电子探针分析的主要信息，根据特征频率(或波长)就可以识别样品中存在哪种元素，这是电子探针定性分析的基本原理。在定性分析的释谱过程中要注意谱线的判别，峰的重叠和X射线的形态变化所引起的峰位的变化。本文主要在EMX-SM7型电子探针上进行谱线分峰研究，鉴别干     

用5晶（7晶）X射线衍线仪研究半导体薄膜材料

５晶（７晶）Ｘ射线衍射仪非常适合于高级半导体单昌，特别是Ⅲ－Ⅴ族和Ⅱ＝Ⅵ经合物半导体及其异质体外延层的特性分析。本文将简单地介绍５晶（７晶）Ｘ射线衍射仪，以及在半导体薄膜研究中的结果。     

X射线探测器前端信号处理芯片设计

基于ASMC 0.35μm2P3MCMOS工艺,完成了对x射线探测器前端信号处理芯片的设计.该设计主要包括前端读出电路和信号处理电路.在模拟仿真的基础上完成了版图布局和设计,并对芯片进行了流片验证和测试.测试结果表明,该芯片能探测到的光电流范围为10pA到5nA.并实现了光电转换,多路选择等功能.该芯片的电源电压5V,整体功耗为40mW,工作频率可在100kHz到1MHz之间,线性度达到0.35%,具有较低的噪声性能.     

HgCdTe块晶不完整性的X射线双晶衍射研究

利用高精度Ｘ射线双晶衍射术，研究了碲熔剂法生长的Φ１５ｍｍ的Ｈｇ０．８Ｃｄ０．２Ｔｅ块晶片的结构不完整性，发现工艺大致相同的块晶晶体完整性差别十分明显，但它们的晶格不完整性沿径向的分布具有共同特征─呈Ｗ形，这表明晶格不完整性与晶体生长或退火处理过程中的应力场有关．     

激光等离子体X光谱的高精度测量

通过比较各种光谱实验数据的处理方法,本文得到了高精确度的砷化镓激光等离子体X射线光谱,与理论值相比,最大相对误差不超过0.03%.     

Propagation in cylindrical fibres with anisotropic crystal cores

Expressions for the fields and propagation constants in cylindrical dielectric waveguides with umaxial crystal cores are found. The propagation constants of biaxial-crystal-cored guides are then deduced from a coupled-mode analysis, using the uniaxial solutions as ideal modes.     

High accuracy multiwavelets with short supports

We show how to construct multiwavelets from wavelets. The multiwavelets resulting from such constructions retain accuracy and regularity or the original wavelets and are all supported on a shorter interval than the original wavelets. In fact, we can arrange, at the expense of the number of channels, to obtain any accuracy obtainable for compactly supported wavelets and support in a prescribed neighborhood of the unit interval     

Detection of curved edges at subpixel accuracy using deformablemodels

One approach to the detection of curves at subpixel accuracy involves the reconstruction of such features from subpixel edge data points. A new technique is presented for reconstructing and segmenting curves with subpixel accuracy using deformable models. A curve is represented as a set of interconnected Hermite splines forming a snake generated from the subpixel edge information that minimises the global energy functional integral over the set. While previous work on the minimisation was mostly based on the Euler-Lagrange transformation, the authors use the finite element method to solve the energy minimisation equation. The advantages of this approach over the Euler-Lagrange transformation approach are that the method is straightforward, leads to positive m-diagonal symmetric matrices, and has the ability to cope with irregular geometries such as junctions and corners. The energy functional integral solved using this method can also be used to segment the features by searching for the location of the maxima of the first derivative of the energy over the elementary curve set     

X-ray inspection of TSV defects with self-organizing map network and Otsu algorithm

Through-silicon via (TSV) is one of the most critical elements in 3D integration, where defects such as unfilled bottom and holes are very common. Thus, defect detection is of great importance to improve products quality. In this work, a non-destructive TSV defect detection method using X-ray imaging is introduced. Seven features representative of TSVs are extracted from the images, and then inputted into a self-organizing map (SOM) network for classification and testing. The results demonstrate that the normal TSVs and defective TSVs can be distinguished obviously by SOM network. The voids inside the TSVs are further located qualitatively using the Otsu algorithm and verified by the SEM images. These prove the feasibility of X-ray inspection of TSV defects with SOM network and Otsu algorithm.     

Equivalent source analysis of curved edge tapered slot-line antennas

An equivalent source model for the analysis of curved edge tapered slot-line antenna is developed, which employs effective filamentary currents along the conductor edges of the slot, but forces the electric field produced by the currents to satisfy the boundary condition on the whole conductor surface. This idea is implemented by method of moments with collocation technique, and applied to analyze a tapered slot-line antenna with arbitrarily curved edge.     

激光工作物质的高精度检验

一、引言 光学干涉仪是测量光学元件面形、评价透镜质量最常用的手段。七十年代人们将微型电子计算机及相位探测技术应用到干涉计量上,使干涉条纹的数据处理成为独立系统而将高精度光学元件的检验发展到一崭新阶段。美国贝尔实验室首先研制成带微型计算机的条纹扫描干涉仪,使干涉条纹的测量精度由λ/10提高到λ/50～λ/100。我们运用MarkⅢ型干涉仪测量了各种光学元件及光学材料的质量,对仪器的性能进行了分析和讨论。 二、实验结果和讨论 Mark Ⅲ型激光数字波面干涉仪是将位相测量技术应用于费索干涉仪上,利用实时相位同步检     

Optimization of coupling between photonic crystal resonator and curved microfiber

The evanescent coupling from a photonic crystal resonator to a micron-thick optical fiber is investigated in detail by using a three-dimensional finite-difference time-domain (3D-FDTD) method. Properly designed photonic crystal cavity and taper structures are proposed, and optimal operating conditions are found to enhance the coupling strength while suppressing other cavity losses including the coupling to the slab propagating mode and to the higher-order fiber mode. In simulation, the coupling into the fundamental fiber mode is discriminated from other cavity losses by spatial and parity filtering of the FDTD results. The coupling efficiency of more than 80% into the fundamental fiber mode together with a total Q factor of 5200 is achieved for the fiber diameter of 1.0 /spl mu/m and the air gap of 200 nm between the fiber and the cavity.     

用于速调管的一维光子晶体圆柱腔分析

运用ISFEL3D软件对一维光子晶体圆柱腔和金属圆柱腔进行仿真和分析。研究结果表明,一维光子晶体圆柱腔中与TM010模相邻的TM910模只存在于最外层介质中,频率间隔为213 MHz,不会影响TM010模;一维光子晶体圆柱腔的特性阻抗(94.9Ω)比金属圆柱腔(129Ω)要小,但均匀性要好;在一维光子晶体圆柱腔两端连接漂移管后,TM010模所受影响很小,说明一维光子晶体圆柱腔具有较强的抗干扰能力,这是将一维光子晶体圆柱腔应用在高射频段速调管方面的前提条件。