激光等离子体X射线光谱分峰方法研究

分析了激光等离子体发射的X射线光谱的线型轮廓,构造出三种线型拟合函数,采用最小二乘算法,提出了一种多峰值数据处理方法,并应用于超短超强激光脉冲加热产生的镁铝等离子体的类H类He X光光谱验证其有效性,比较三种拟合线型的拟合精度。     

高精度X射线柱面弯晶检测方法

A novel method of cylindrical curved crystal inspection is presented utilized the X-ray tube as the light source and the CMOS detector coated scintillator fibre faceplate as the on-line recorder. According to the design of the high accuracy coaxial turntable, the whole cylindrical curved crystal surface is converted into several line segments to be detected separately, and the arrangement of optical paths and the position shift of spectral lines are calculated analytically. The iron target X-ray tube (the wavelength of K_β feature spectral line is 0.193 6 nm) is selected as the experimental light source. The iron material X-ray tube is chosen as the X-ray source. The sample is quartz cylindrical curved crystal with the 120 mm radius of curvature. The feature spectral lines of Fe-K_α and Fe-K_β are observed clearly. The Fe-K_α spectral line is shifted 96 μm through analyzing image of 9 sample locations on the cylindrical curved crystal. The deviation of the radius is 40 μm and ΔR/R is 0.033%. It shows that the sample was curved in high accuracy. The tested cylindrical curved crystal has been applied on the experiments carried on the large laser facility and the high performance spectral data is acquired. It demonstrates that the method of curved crystal inspection is available and useful.     

基于有限元法的高分辨透射光栅谱仪关键件结构优化设计

光栅室作为高分辨透射光栅谱仪的关键件,对谱仪整体稳定性起决定性作用.文中运用Pro/E对光栅室进行三维建模,以结构质量最轻为优化目标,截面尺寸为设计变量,建立优化模型,求得最优截面参数.运用ANSYS进行动静态分析,分析结果表明,优化后的光栅室刚度、强度均满足设计要求,结构前4阶固有频率均大于耙球基频40 Hz,不会发生共振.     

A High-Efficiency X-Ray Crystal Spectrometer for X-Ray Thomson Scattering

Highly oriented pyrolitic graphite (HOPG) has high X-ray diffraction efficiency due to its unique mosaic crystal structure, and thus is very suitable for its application to X-ray Thomson scattering measurement of solid-density plasmas. In this article, by using the K-shell X-ray source from laser-produced Ti plasma, the properties of the HOPG spectrometer are characterized and compared with those of the flat Pentaerythritol (PET) spectrometer. The results show that the diffraction efficiency of the HOPG spectrometer under focusing condition is an order higher than that of the PET spectrometer, while the spectral resolution of the HOPG is about 320, high enough to be used in the measurement of X-ray Thomson scattering spectra.     

宽光谱在线弯晶谱仪研制

研制了高精度在线准直、超宽光谱范围和高能谱分辨的在线凸圆柱面弯晶谱仪。使用耦合针状CsI（Tl）闪烁体的大面阵CMOS相机对X射线光谱进行在线测量,用QTZ（1010）（2d=0.851 2 nm）X射线晶体的能谱测量范围是1.84~7.38 keV,能谱分辨880@2.375 keV,动态范围 1 000。在神光-Ⅲ主机高功率激光装置上,对钛激光等离子体发射的X射线谱进行实验测量,获得了优质的光谱图像;对钛离子X射线精细结构光谱进行了辨识,与理论计算和其他实验结果吻合。该谱仪用于神光-Ⅲ主机通用诊断搭载平台,具有抗瞬发超强电磁脉冲干扰能力,工作稳定。     

高次谐波份额测量滤片法及其应用

惯性约束聚变实验对数据测量精度有着很高的要求,诊断设备需要向绝对测量的方向发展,对标定提出了很高的要求。北京同步辐射装置（BSRF）提供了良好的标定光源,其光源特性,如高次谐波份额的数值研究,对标定工作和ICF精密诊断十分重要。通过测量BSRF上4B7B光束线的软X射线源上带有或不带有滤片的标准探测器的电流,研究了不同滤片对单色X射线的透射率曲线,并建立了拟合的理论透射率曲线。根据数据分析,计算出单色光源中二次谐波的比例。实验结果显示,二次谐波在软X射线能段主要集中在180~300 eV以及450~800 eV,所占份额大部分在15%以下,最大可达到25%左右。利用测量的高次谐波份额,开展了对平响应滤片透过率以及X射线二极管灵敏度的修正工作,修正后的结果和理论相符,极大地提高了诊断设备精密诊断能力。完整的理论模型和实验相互验证,说明基于滤片的高次谐波份额测量技术目前已经成熟并且具有广阔的应用前景。     

2 000~2 800 eV软X光入射CsI(TI)闪烁体的探测效率标定

CsI（Tl）闪烁体是X光转换为可见光的一个比较重要的部件,其转换效率对惯性约束聚变中的X光诊断发挥关键作用。利用北京同步辐射装置4B7A中能束线,针对2 000~2 800 eV能段的软X光入射不同厚度CsI（Tl）闪烁体后转换为可见光的探测效率进行了标定。文章详细分析了CsI（Tl）闪烁体在X光激发下的能量沉积和出射可见光的效率。整个探测系统包括入射兼容光源、标准探测器、快门、CsI（TI）闪烁体块、黑腔盒,SI1000可见光CCD等。用曲线拟合的方法归一化入射兼容光,利用SI1000可见光CCD相机作接收系统记录出射可见光,在CCD线性工作范围内,得到CCD上记录的出射可见光计数。标定实验获得2 000~2 800 eV能区标定探测器电流,CCD计数,得到了同一曝光时间下CCD计数和入射光子数的比值,即探测效率。实验结果表明,随着CsI（Tl）闪烁体厚度的增加,探测效率也随之提高。实验方法为后续选择合适厚度闪烁体做软X光探测做基础。     

球面晶体分析器在等离子体X射线诊断中的应用

为了诊断高温等离子体X射线,利用晶体布喇格衍射原理研制了新型的球面晶体分析器,α-石英为衍射晶体,球面的半径为250 mm.对球面晶体分析器分别进行静态X射线衍射实验和Z箍缩聚爆实验,富士磷屏(IP)成像板和感光胶片分别得到了清晰的Cu等离子体和Ti等离子体谱线.对实验所得谱线进行分析,石英球面晶体分析器光谱分辨力好于...