X-ray spectrometers with cylindrical, spherical and toroidal dispersive elements
This paper describes a series of crystal spectrometers for soft x-ray diagnostics of pulsed plasmas. Most use high quality quartz crystals with different orientations of their crystal planes, attached by optical contact to spherical and toroidal substrates. The authors developed special procedures to attach spherical Johansson quartz crystals with optical contact, and to mount Cauchois type (transmission) crystals. Some mica crystals can be connected to the substrate with glue. The spectrometers cover an extended energy range, from the low end (0.7 keV) in reflection with a Johann or Johannson configuration to the high end (200 keV) with the Cauchois crystal. They use film as x-ray detector. They pay special attention to spectral and spatial resolutions. These characteristics are modeled analytically and compared with experimental calibration. Some crystals have spectral resolution better than 9 x 10{sup {minus}5}, and spatial resolution of a few microns. One of these is a uniquely large (100 mm by 40 mm) quartz crystal bent to a 3,770 mm radius. The spectrometer was used on a 500 kA plasma focus, with enough resolution to estimate temperature and density of the argon plasma from the line shapes, and the fraction of current in an electron beam from the line's polarization. Compared to a conventional spectrometer with a cylindrically bent crystal, the spectrometer with a chemically polished spherical crystal has much better resolution of the fine structure.
- Research Organization:
- Ecopulse, Inc., Springfield, VA (US)
- OSTI ID:
- 20050664
- Resource Relation:
- Conference: 1999 IEEE International Conference on Plasma Science, Monterey, CA (US), 06/20/1999--06/24/1999; Other Information: PBD: 1999; Related Information: In: The 26th IEEE international conference on plasma science, 342 pages.
- Country of Publication:
- United States
- Language:
- English
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