title: Mapping and uncertainty analysis of energy and pitch angle phase space in the DIII-D fast ion loss detector.
abstract: New phase space mapping and uncertainty analysis of energetic ion loss data in the DIII-D tokamak provides experimental results that serve as valuable constraints in first-principles simulations of energetic ion transport. Beam ion losses are measured by the fast ion loss detector (FILD) diagnostic system consisting of two magnetic spectrometers placed independently along the outer wall. Monte Carlo simulations of mono-energetic and single-pitch ions reaching the FILDs are used to determine the expected uncertainty in the measurements. Modeling shows that the variation in gyrophase of 80 keV beam ions at the FILD aperture can produce an apparent measured energy signature spanning across 50-140 keV. These calculations compare favorably with experiments in which neutral beam prompt loss provides a well known energy and pitch distribution.
authors.affiliation: General Atomics, PO Box 85608, San Diego, California 92186-5608, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Pace
authors.affiliation: Department of Physics, University of Hawaii, Hilo, Hawaii 96720-4091, USA.
authors.forename: R
authors.initials: R
authors.lastname: Pipes
authors.affiliation: General Atomics, PO Box 85608, San Diego, California 92186-5608, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Fisher
authors.affiliation: General Atomics, PO Box 85608, San Diego, California 92186-5608, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Van Zeeland