Novel instrumentation for spectrally resolved soft x-ray plasma tomography: Development and pilot results on TEXTOR

Abstract

A novel instrumentation for wavelength-and time-resolved plasma emission tomography in the range 0.1-4 keV has been demonstrated on the Torus Experiment for Technology Oriented Research ͑TEXTOR͒. The technique is intended for reconstruction of distributions of local emission coefficients ͑LEC͒ for selected spectral lines of impurity ions. Further determination ͑with additional data on electron density and temperature͒ of spatial distributions of impurity ions at particular ionization stages will become feasible. Spectrally selective plasma images at several viewpoints around plasma are obtained with miniature pinhole cameras supplemented with multilayer mirrors as dispersion elements. The x-ray image is converted to a visible image and transported by a fiber bundle to a gain enhanced recording camera with an electron bombarded charge coupled device tube. A part of the system has been installed on temporary TEXTOR ports. First demonstration results have been obtained on plasma imaging and on subsequent LEC reconstruction using a modified iterative sinogram restoration tomography algorithm. The complete diagnostics will be operational after the TEXTOR shutdown in 2001.

X-ray imaging crystal spectroscopy for use in plasma transport research

“…The code assumes a spherically bent Bragg reflector, making THACO usable for multilayer-mirror based instruments as well. 16 The spectrometer is completely described in a compact ASCII format that is used by both the inversion and forward modeling tools, enabling the software to be used for scoping and design studies for new spectrometers. THACO will be described in substantial detail in Ref.…”

Multilayer optics for XUV spectral region: technology fabrication and applications

“…Extreme ultraviolet (EUV) projection lithography in the 13 nm spectral region using both pulse plasma and SR sources seems to be potentially the largest application eld for multilayer developments [7][8][9]. X-ray optics now has increasing demand as a tool for solving problems in SR technology [10], fusion plasma diagnostics [11] and X-ray astronomy [12][13][14].…”

Measuring one-dimensional and two-dimensional impurity density profiles on TEXTOR using combined charge exchange-beam emission spectroscopy and ultrasoft x-ray tomography

“…7,8 The two systems are complementary: where the CXRS/BES is an active method that returns one-dimensional impurity density profiles without needing an absolute calibration, the USXT is a passive method that produces 2D density profiles, but an absolute calibration is necessary.…”