The crystals of the orthorhombic form grown in the presence of 15% polyethylene glycol and 20 mM sodium acetate buffer were chosen for further analysis. Two kinds of crystals on cell dimensions were found for X-ray diffraction analysis, one from ammonium sulfate and the other from polyethylene glycol 6000 as precipitants. Gamma-Glutamyltranspeptidase (EC 2.3.2.2) from Escherichia coli K-12 has been purified and crystallized by means of vapor diffusion in hanging drops. Kumagai, H Nohara, S Suzuki, H Hashimoto, W Yamamoto, K Sakai, H Sakabe, K Fukuyama, K Sakabe, N (Modified author abstract)Ĭrystallization and preliminary X-ray analysis of gamma-glutamyltranspeptidase from Escherichia coli K-12. This spectrometer seems to be a most appropriate instrument for evaluation of crystal properties. In the third part some technical details of a triple crystal spectrometer built by the author at Polytechnic Institute of Brooklyn are given. The second part is a compilation of the diffraction properties of a number of crystals as reported by other authors. A number of crystals were evaluated, and the energy dependence of the diffraction properties of (002) PET, (111) Ge, (101) ADP, (001) KAP, and (001) RAP are reported. The principles of crystal evaluation analysis as they apply to the special problems of X-ray astronomy are presented.
The first part is an analysis of the principles involved in X-ray crystal evaluation and how they are applied to a number of crystals. X-ray evaluation of crystals for stellar spectrometers The experimental techniques for studying the real diamond structure in optimizing crystal-growth technology are proven to be highly efficient.« less The critical thicknesses of plastic relaxation onset in CVD diamond films are calculated. The formation of dislocation bundles at the film-substrate interface in the epitaxial structures has been revealed by plane-wave topography these dislocations are likelymore » due to the relaxation of elastic macroscopic stresses caused by the lattice mismatch between the substrate and film. The nitrogen concentration in high-pressure/high-temperature (HPHT) diamond substrates is estimated based on X-ray diffraction data. The main structural defects (dislocations, stacking faults, growth striations, second-phase inclusions, etc.) formed during crystal growth have been revealed. The conditions of a diffraction analysis of diamond crystals using Ge monochromators have been optimized. Structural features of diamond single crystals synthesized under high pressure and homoepitaxial films grown by chemical vapor deposition (CVD) have been analyzed by double-crystal X-ray diffractometry and topography. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.Īnalysis of synthetic diamond single crystals by X-ray topography and double-crystal diffractometry For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45.
Lane Stodiek, Wolfgang von Goeler, Schweickhard E. X-ray imaging crystal spectrometer for extended X-ray sourcesīitter, Manfred L.
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