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http://dx.doi.org/10.1103/physreva.36.795 | DOI Listing |
Rev Sci Instrum
October 2018
Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, China.
Newly developed large-area pixelated two-dimensional detector and two-crystal assemblies were deployed for the first time on tokamaks to enable time-resolved Bragg-diffracted x-ray imaging with good framing rate and water-cooling capabilities for in-vacuum long-pulse operations. High-quality helium-like (He-like) and hydrogen-like (H-like) argon spectra have been observed simultaneously for the first time on a single detector for a wide range of plasma parameters to infer both ion temperature and rotation profiles and support studies on spontaneous rotation, impurity transport, and RF physics. Since tokamak plasmas rotate in both the poloidal (θ) and toroidal (ϕ) directions, a reliable wavelength calibration is needed to account for the correct Doppler shift as well as to compute the spectrometer's instrumental function.
View Article and Find Full Text PDFRev Sci Instrum
October 2008
Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
We describe upgrades to a compact grazing-incidence spectrometer utilized on the National Spherical Torus Experiment for monitoring light and heavy impurities. A fast-readout charge couple device camera has been implemented that allows the recording of spectra with up to 25 ms time integration. This capability is used to study the time evolution of the K-shell emission of hydrogenlike and heliumlike boron, carbon, nitrogen, and oxygen between 10 and 65 A.
View Article and Find Full Text PDFWe report on what we believe to be the first use of toroidally bent crystals to record two-dimensional, spatially resolved, monochromatic images of laser-produced fusion plasmas combined with a 34-ps fast x-ray framing camera. An array of five toroidal silicon (311) and five toroidal germanium (311) crystals was developed. The imaging properties of the geometries are checked by a ray-tracing program and are compared with experimental results.
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