title: Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U.
abstract: A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.
authors.affiliation: MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA.
authors.forename: I
authors.initials: I
authors.lastname: Faust
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: L
authors.initials: L
authors.lastname: Delgado-Aparicio
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Bell
authors.affiliation: The Johns Hopkins University, Baltimore, Maryland 21209, USA.
authors.forename: K
authors.initials: K
authors.lastname: Tritz
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: A
authors.initials: A
authors.lastname: Diallo
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Gerhardt
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: B
authors.initials: B
authors.lastname: LeBlanc
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Kozub
authors.affiliation: MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Parker
authors.affiliation: MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Stratton