Divertor leg filaments in NSTX-U

"Snowflake" divertor configuration in NSTX

Integrated models to study the impact of ELMs and disruptions on lithium in the NSTX divertor

Lithium as a potential plasma-facing material has many attractive features including a reduction in recycling of hydrogenic species and ability to withstand high heat and neutron fluxes in fusion reactors. Recent analysis of the National Spherical Torus eXperiment (NSTX) device has shown significant and recurring benefits of lithium coatings on plasma-facing components performance. To self-cons...

Taming the Plasma Material Interface with the "Snowflake" Divertor in NSTX

Steady-state handling of divertor heat flux is a critical issue for ITER and future conventional and spherical tokamaks with compact high power density divertors. A novel ”snowflake” divertor (SFD) configuration was theoretically predicted to have significant magnetic geometry benefits for divertor heat flux mitigation, such as an increased plasma-wetted area and a higher divertor volume availa...

Electron Bernstein Wave Research on CDX-U and NSTX

Mode-converted electron Bernstein waves (EBWs) potentially allow the measurement of local electron temperature (Te) and the implementation of local heating and current drive in spherical torus (ST) devices, which are not directly accessible to low harmonic electron cyclotron waves. This paper reports on the measurement of X-mode radiation mode-converted from EBWs observed normal to the magnetic...

Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U.

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 ang...