Demonstration of Tokamak Ohmic Flux Saving by Transient Coaxial Helicity Injection on NSTX (open access)

Demonstration of Tokamak Ohmic Flux Saving by Transient Coaxial Helicity Injection on NSTX

Transient Coaxial Helicity Injection (CHI) started discharges in NSTX have attained peak currents up to 300 kA and when these discharges are coupled to induction, it has produced up to 200 kA additional current over inductive-only operation. CHI in NSTX has shown to be energetically quite efficient, producing a plasma current of about 10 A/Joule of capacitor bank energy. In addition, for the first time, the CHI produced toroidal current that couples to induction continues to increase with the energy supplied by the CHI power supply at otherwise similar values of the injector flux, indicating the potential for substantial current generation capability by CHI in NSTX and in future toroidal devices. __________________________________________________
Date: April 23, 2010
Creator: Raman, R.; Mueller, D.; Nelson, B. A.; Jarboe, T. R.; Gerhardt, S.; Kugel, H. W. et al.
System: The UNT Digital Library
Development of backlighting sources for a Compton Radiography diagnostic of Inertial Confinement Fusion targets (open access)

Development of backlighting sources for a Compton Radiography diagnostic of Inertial Confinement Fusion targets

An important diagnostic tool for inertial confinement fusion is time-resolved imaging of the dense cold fuel surrounding the hot spot. Here we report on the source and diagnostic development of hard x-ray radiography and on the first radiographs of direct drive implosions obtained at photon energies up to about 100keV, where the Compton effect is the dominant contributor to the shell opacity. The radiographs of direct drive, plastic shell implosions obtained at the OMEGA laser facility have a spatial resolution of {approx}10um and a temporal resolution of {approx}10ps. This novel Compton Radiography is an invaluable diagnostic tool for Inertial Confinement Fusion targets, and will be integrated at the National Ignition Facility (NIF).
Date: April 23, 2010
Creator: Tommasini, R
System: The UNT Digital Library