用于X射线时空分辨测量的弯晶谱仪

为了测量激光聚变产生的0.2～0.37 nm范围内的等离子体X射线, 设计了一种基于空间和时间分辨的聚焦型弯晶谱仪. 将在700℃时弯曲后的LiF(2d＝0.403 nm)晶体作为色散元件, 布喇格衍射角的变化范围为30～67.5°, 弯晶粘贴在离心率和焦距分别为0.9586和1350 mm的椭圆形不锈钢基底上. 利用弯晶谱仪配X光CCD相机在星光Ⅱ激光(0.35 μm, 60～80J, 700 ps)装置上摄取了钛平面靶发射的X射线光谱, 实验结果表明它的光谱分辨率能达到0.001 nm.     

用三坐标测量机调整掠入射光栅谱仪

用三坐标测量机调整掠入射光栅谱仪是我们在研制掠入射光栅谱仪中采用的新方法．我们用这种方法研制了一台曲率半径为１ｍ的光栅谱仪，在２—３２ｎｍ波段范围内，谱线分辨达０．００５ｎｍ，与通常采用的用光源摄谱调整光栅谱仪的方法相比，节省了人力、物力，缩短了研制周期．     

四端光纤补偿网络的理论分析

强度干扰是阻碍强度调制光纤传感器发展及应用的关键问题.研究表明,光纤网络补偿方法对抑制强度干扰是一种行之有效的方法.作者经过深入的研究,提出了一种先进的四端光纤补偿网络结构.本文对四端光纤补偿网络进行了全面、系统的分析,揭示了网络的特性.这对于强度调制光纤传感器的发展及应用具有重要的意义.同时,对于强度调制光学测量系统也具有一定的意义.     

软X射线分光晶体KAP的反射率特性

弯晶谱仪是激光等离子体软X射线的有效诊断工具,KAP是弯晶谱仪的分光晶体之一.利用原子散射因子和结构因子分量,以及镶嵌晶体模型计算KAP的积分反射率,表明KAP的积分反射率与波长有关,先随波长增大而减小,后随波长增大而增大.此外,还计算了KAP的峰值反射率、半最大值宽度、能量宽度和能量分辨率,表明峰值反射率和能量分辨率随波长增大而减小.     

软X射线果品品质在线检测算法研究

针对果品品质检测中内在品质检测的难点,分析了果品软X射线检测的图像特点,根据正常果肉与变质部分的成像差异,提出了基于一类支持向量机分类器和外轮廓检测的软X射线果品品质在线检测算法。算法通过超球面OC-SVM建立分类器,根据果品图像由边缘到果核的环状灰度变化,以正常果肉的相对灰度和相对位置作为训练样本,统计计算得到正常果肉的灰度分布范围;轮廓识别采用坐标变换及曲线求二阶导数,避免了果核位置判断误差造成的误判。实验证明,该算法对于内、外部果肉变质的水果,都有良好的识别效果,识别率达88％以上。     

Elliptically-bent crystal spectrograph for X-ray diagnosis of laser-produced plasmas

In order to measure spatially and temporarily resolved laser-produced plasma X-ray spectra in 0.2 - 2 nm region, a novel two-channel elliptically-bent crystal spectrograph has been developed. Dispersive elements are LiF, PET, Mica, and KAP crystals, which cover Bragg angles in the range of 30 - 67.5 degrees. Eccentricity and focal distance of twin ellipses are 0.9586 and 1350 mm, respectively. Spatially resolved spectrum is photographically recorded with an X-ray film or X-CCD camera in one channel, and temporarily resolved one is photographically recorded with an X-ray streak camera in another channel, thus spatially and temporarily resolved spectra can be simultaneously obtained. Spectral images were acquired with X-CCD and PET in SHENGUANG-II laser facility, and experimental results show that the spectral resolution of the spectrograph is about 0.002 nm.     

用于诊断激光等离子体X射线的双通道椭圆弯晶谱仪

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及布拉格衍射的特点,研制了双通道椭圆弯晶谱仪(以下简称"弯晶谱仪").采用独特的双通道结构能够对高温等离子体所发出的X射线同时进行空间和时间分辨测量,测量的波长范围为0.2～2 nm,布拉格角的覆盖范围是30°～67.5°.阐述了弯晶谱仪的基本结构.重点介绍了对LiF分光晶体进行的X射线衍射实验及在"星光Ⅱ" 激光装置上进行的激光打靶实验.得到了钛等离子体X射线的发射谱图像,经过分析,发现弯晶谱仪的空间分辨率能够达到0.0011 nm.最后,提出对弯晶分析器的特性、制作工艺及检测方法还必须进行进一步的深入研究.     

声表面波扩频多符号检测器研究

报道了一种用于差分双相相移键控/双相相移键控调制信号的声表面波扩频多符号检测器;基于声表面波,实现了直接序列扩频信号匹配滤波和多符号延迟差分解调的融合;研制了13位巴克码的4符号DBPSK/BPSK扩频多符号检测器,并对该检测器进行了实验测试和性能分析.     

High-resolution X-ray focusing concave (elliptical) curved crystal spectrograph for laser-produced plasma

The X-ray spectrum emitted from laser-produced plasma contains plentiful information.X-ray spectrometer is a powerful tool for plasma diagnosis and studying the information and evolution of the plasma.X-ray concave(elliptical)curved crystals analyzer was designed and manufactured to investigate the properties of laser-produced plasma.The experiment was carried out on Mianyang Xingguang-ⅡFacility and aimed at investigating the characteristics of a high density iron plasma.Experimental results using KAP,LIF,PET,and MICA curved crystal analyzers are described,and the spectra of Au,Ti laser-produced plasma are shown.The focusing crystal analyzer clearly gave an increase in sensitivity over a flat crystal.     

Elliptically-bent crystal spectrograph for X-ray diagnosis of laser-produced plasmas

In order to measure spatially and temporarily resolved laser-produced plasma X-ray spectra in 0.2 - 2nm region, a novel two-channel elliptically-bent crystal spectrograph has been developed. Dispersive elements are LiF, PET, Mica, and KAP crystals, which cover Bragg angles in the range of 30 - 67.5degrees. Eccentricity and focal distance of twin ellipses are 0.9586 and 1350 mm, respectively. Spatially resolved spectrum is photographically recorded with an X-ray film or X-CCD camera in one channel, and temporarily resolved one is photographically recorded with an X-ray streak camera in another channel,thus spatially and temporarily resolved spectra can be simultaneously obtained. Spectral images were acquired with X-CCD and PET in SHENGUANG-Ⅱ laser facility, and experimental results show that the spectral resolution of the spectrograph is about 0.002 nm.