Author Affiliations
Abstract
1 Institute of Precision Optical Engineering, MOE Key Laboratory of Advanced Micro-Structured Materials, Shanghai Frontiers Science Center of Digital Optics, Shanghai Professional Technical Service Platform for Full-Spectrum and High-Performance Optical Thin Film Devices and Applications, School of Physics Science and Engineering, Tongji University, Shanghai 200092, China
2 Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
Curved crystal imaging is an important means of plasma diagnosis. Due to the short wavelengths of high-energy X rays and the fixed lattice constant of the spherical crystal, it is difficult to apply the spherical crystal in high-energy X-ray imaging. In this study, we have developed a high-energy, high-resolution X-ray imager based on a toroidal crystal that can effectively correct astigmatism. We prepared a Ge toroidal crystal for backlighting Mo Kα1 characteristic lines ( keV) and verified its high-resolution imaging ability in high-energy X-ray region, achieving a spatial resolution of 5–10 µm in a field of view larger than 1.0 mm.
laser plasma diagnostics toroidal crystal monochromatic X-ray imaging Chinese Optics Letters
2023, 21(10): 103401
Author Affiliations
Abstract
This paper explores the parameter measurement in laser produced plasma by X-ray line profile spectrscopy. The experiment was conducted on the SG-II laser facility. A 0.35 μm laser beam was focused on a solid chlorine (Cl) target in a vacuum chamber to produce a laser chlorine plasma and the high resolution X-ray elliptical bent crystal spectrograph was used to obtain the X-ray fine structure energy spectrum of the chlorine plasma radiation. The line integrated intensity ratio between H-like Cl (1s-3p) (Lyman-) and He-like Cl (1s2-1s3p) (He-) transitions was used for calculation of the electron temperature. By assuming optically thin, the Lyman-stark broadened profile was utilized to measure the electron density. Obtained experimental results show that the volume averaged electron temperature of Te is about 450 eV and the electron density of Ne is approximately 7.5×1022 cm-3. In addition, the line Full Width at Half Maximum (FWHM) was analyzed. The uncertainty in Ne due to uncertainties in the temperature and the assumed background level was also simply discussed and it is estimated to be within 25%. As a result, the experimental spectroscopic method may become a reference for diagnosing future higher-compression implosions.
X射线能谱 谱线轮廓 激光等离子体诊断 电子密度 X射线谱仪 X-ray spectra spectral line shape laser plasma diagnostics electron density X-ray spectrometer Collection Of theses on high power laser and plasma physics
2014, 12(1): 1737
开展了利用X射线特征谱轮廓诊断激光等离子体状态参数的研究。在"神光II"激光装置上, 将 0.35 μm频谱激光束聚焦于真空室内固体氯(Cl)元素靶上产生激光氯等离子体, 利用高分辨X射线椭圆弯晶谱仪获取高能谱分辨激光氯等离子体辐射的X射线精细结构能谱。用类氢(1s-3p)和类氦(1s2-1s3p)氯离子能级跃迁光谱线的光强度比率计算了激光等离子体的电子温度; 然后在假定光性为薄的情况下, 利用X射线谱线Lyman-线形轮廓的Stark效应所产生的谱线展宽测量了等离子体的电子密度。实验获得的激光等离子体日冕区内体平均电子温度约为450 eV, 电子密度约为7.5×1022 cm-3。文中还简单分析了能谱线的半高全宽度(FWHM)值以及诊断过程引入的诊断误差, 初步预估诊断误差可控制在25%以内。该项工作为X射线特征谱轮廓法进一步应用于激光聚变靶丸压缩度精度测量等工作提供了参考。
X射线能谱 谱线轮廓 激光等离子体诊断 电子密度 X射线谱仪 X-ray spectra spectral line shape laser plasma diagnostics electron density X-ray spectrometer
