title: Analysis techniques for diagnosing runaway ion distributions in the reversed field pinch.
abstract: An advanced neutral particle analyzer (ANPA) on the Madison Symmetric Torus measures deuterium ions of energy ranges 8-45 keV with an energy resolution of 2-4 keV and time resolution of 10 μs. Three different experimental configurations measure distinct portions of the naturally occurring fast ion distributions: fast ions moving parallel, anti-parallel, or perpendicular to the plasma current. On a radial-facing port, fast ions moving perpendicular to the current have the necessary pitch to be measured by the ANPA. With the diagnostic positioned on a tangent line through the plasma core, a chord integration over fast ion density, background neutral density, and local appropriate pitch defines the measured sample. The plasma current can be reversed to measure anti-parallel fast ions in the same configuration. Comparisons of energy distributions for the three configurations show an anisotropic fast ion distribution favoring high pitch ions.
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Anderson
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: W
authors.initials: W
authors.lastname: Capecchi
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Bonofiglo
authors.affiliation: University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Sears