神光Ⅲ原型针孔相机的研制与应用

介绍了神光Ⅲ针孔相机的研制与应用,实现了针孔相机的在线连续测量功能,在不破坏靶室真空条件下获取数据和调节,提高了数据获取速度和精度,实现了X光焦斑的定量、精密测量。     

基于多锥晶体的多能点X射线光谱仪北大核心CSCD

为了克服传统弯曲晶体光谱仪存在检测的像差问题,基于衍射聚焦X射线特征能量谱范围、衍射光源位置、聚焦成像距离等关键的物理参数,设计了具有高光谱分辨力及宽光谱检测范围的多锥晶体X射线谱仪。从结构原理上讨论了该光谱仪的特点,研制完成了连续光滑的多锥表面X射线衍射聚焦弯曲晶体,通过单次X射线衍射聚焦诊断实验即能实现不同能量X射线无像差检测。对Ti的K_(α)与K_(β)射线光谱进行了多次衍射聚焦检测实验,获得了不同聚焦成像位置下的K_(α)与K_(β)特征谱线强度分布,并完成了光谱仪谱线聚焦能力与光谱分辨力分析。根据晶体对X射线聚焦程度与成像位置的关系,进行了不同聚焦成像位置处连续锥面光谱仪的聚焦性能分析,确定了最佳聚焦位置。实验结果表明:多锥晶体X射线光谱仪的聚焦能力得到显著提升,能谱检测范围可以覆盖4.51—5.14 keV,且在较大尺寸光源基础上仍能保证光谱分辨力达到600以上。     

整形脉冲信号处理方法及低温辐射流偏差

平响应X射线二极管目前已经广泛应用在国内外大型激光装置,用于角分布X射线辐射流的测量。在实际实验中,平响应X射线二极管会对整形脉冲驱动辐射源产生台阶变化的辐射流图像进行测量。为了保证信噪比良好,单一信号会接入示波器多通道,然后对不同通道信号进行数据处理,并且拼接得到最后信噪比很好的图像。该研究主要对这种数据处理方式进行了介绍,并给出了理论计算,同时对低温辐射流还原计算中的一种偏差做了理论近似和数值模拟,得到了偏差的相对不确定度。耦合所有因素的不确定度,得到了平响应X射线二极管的整体不确定度随辐射温度的变化曲线,实现了精密化诊断,完成了实验对于诊断的需求。     

Quantitative Measurement of the Proportions of High-Order Harmonics for the 4B7B Soft-X-Ray Source at Beijing Synchrotron Radiation Facility

A transmission grating coupled with an X-ray charge coupled device(CCD)is used to quantitatively measure the proportion of high-order harmonics of the soft-X-ray source of beam line 4B7B.The results show that the monochromatic X-ray has third-order and second-order harmonics.The proportion of second-order harmonic of 4B7B is less than 9.0%and the thirdorder harmonic is below 0.7%when no suppressing method is applied.When suppression methods are used,the proportion of second-order harmonic is less than 1.7%and the third-order harmonic is ignorable.     

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。     

用改进的透射光栅谱仪定量测量x射线能谱

利用最新研制的小型化透射光栅谱仪在“神光Ⅲ”原型实验装置上测量了激光注入金腔靶时激光注入口的X射线能谱,首次实现了在上极点附近对柱腔注入口辐射的测量,且实现对x射线的二维空间分辨和谱分辨的测量。改进后的透射光栅谱仪成像系统首次使用一种错位排布的狭缝阵列结构来解决因谱仪尺寸减小带来的能谱分辨问题,并同时达到提高系统空间分辨能力的目的,实现了ICF实验研究中对移动方便和高空间分辨的需求。     

Experimental Study of the X-Ray Radiation Source at Approximately Constant Radiation Temperature

An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and     

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.     

透射光栅谱仪定量测量技术研究

光栅的衍射效率和记录仪器的响应特性是影响透射光栅谱仪测量精度的关键因素,在北京同步辐射装置(BSRF〕3W1B束线上分别对每mm2 000线的自支撑透射光栅衍射效率和X光CCD的响应特性进行了精确标定,获得150～1 500 eV能区光栅的绝对衍射效率和CCD的响应特性数据。对实验结果进行拟合,并通过内插外推的方式将结果推广到150～1 500 eV整个能区;此外,通过零级抑制技术,解决了透射光栅谱仪的零级饱和问题,改善了高能区光谱质量。     

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。