Multilayer mirror and foil filter AXUV diode arrays on CDX-U spherical torus Journal Article uri icon



  • Recent upgrades to CDX-U spherical torus diagnostics include two 10-channel AXUV diode arrays. The multilayer mirror (MLM) array measures the λ150 O VI brightness profile in the poloidal plane using the Mo/B4C synthetic multilayer structures as dispersive elements. The foil filter array has a tangential view and is equipped with interchangeable clear aperture, beryllium and titanium filters. This allows measurements of radiated power, O VI or C V radial distributions, respectively. The O VI and C V emissivity and the radiated power profiles are highly peaked. A Neoclassical impurity accumulation mechanism is considered as an explanation. For radiated power measurements in the Te⩽100 eV plasmas, photon energy dependent corrections must be used in order to account for nonlinear AXUV sensitivity in the range Ephot⩽20 eV. The arrays are also used for characterization of resistive MHD phenomena, such as the low m modes, saw-tooth oscillations and internal reconnection events. Based on the successful operation of the diagnostics, a new ultra soft x-ray multilayer mirror diode AXUV diode array monitoring the 34 Å emissivity distribution of C VI will be built and installed on the National Spherical Torus Experiment.

publication date

  • January 1, 2001

has restriction

  • closed

Date in CU Experts

  • February 19, 2015 3:23 AM

Full Author List

  • Soukhanovskii VA; Stutman D; Iovea M; Finkenthal M; Moos HW; Munsat T; Jones B; Hoffman D; Kaita R; Majeski R

author count

  • 10

Other Profiles

International Standard Serial Number (ISSN)

  • 0034-6748

Electronic International Standard Serial Number (EISSN)

  • 1089-7623

Additional Document Info

start page

  • 737

end page

  • 741


  • 72


  • 1