10月20日|Crystals for Diagnosis and Applications of Flash X-ray Sources

  

  报告题目:Crystals for Diagnosis and Applications of Flash X-ray Sources  

  报告人:  Prof. Dr. Eckhart Förster 

  Institute of Optics and Quantum Electronics, Friedrich-Schiller University (FSU) Jena, Germany 

  时间:   2016年10月20日(星期四) 上午11:00  

  地点:  近代物理所5号楼911会议室 

  Abstract: 

  Much effort has been given world-wide both in high-power laser facilities for laser fusion and in development of modern dedicated synchrotrons and free electron lasers with unique brilliance properties. All these modern flash x-ray sources need dedicated x-ray optics for diagnostics and applications, respectively.  Many experiments require either high luminosity point-to-point imaging in narrow spectral channels or high spectral resolution, sometimes combined with 1-D spatial resolution perpendicular to the dispersion plane. Starting from grating spectroscopy at free electron lasers, we have used Bragg reflections on flat and bent crystals for the harder X-ray range. Also we have used flat and bent crystals at the EBIT facility of LLNL facility and the GSI ion storage ring for high-precision experiments. 

  In order to fulfill all the different demands of these x-ray diagnostic or real-time application experiments, our x-ray optics have been designed by using ray-tracing and Bragg reflection codes for the 1D or 2D bent crystals or combinations thereof. Design of the bent crystal spectrometers starts from values of wavelength (0.01 nm - 3 nm), curvature (radii: 50 mm - 2 m) and imaging parameters (1 - 30). In the preparation process, extreme care has been taken over crystal perfection, selection of optimum reflections, precision bending, and measurement of x-ray imaging and reflection properties. X-ray topographic cameras and diffractometers are used to check the relevant properties of the analyzer crystals.