title: Development of miniaturized, spectroscopically assisted Penning gauges for fractional helium and hydrogen neutral pressure measurements.
abstract: Direct measurements of the helium (He) fractional neutral pressure in the neutral gas around fusion devices is challenging because of the small mass difference between the abundant D2molecules and the He ash which will be produced by deuterium-tritium fusion. To study He exhaust, an in situ Penning gauge system is being developed at UW-Madison that is optimized for good pressure and high spectroscopic sensitivity. Three different anode geometries have been studied regarding their vacuum electrostatic fields, light output, and ion current. The light output of the two new anode configurations are at least one order of magnitude above the currently available designs, hence improving the spectroscopic sensitivity at similar total neutral pressure resolution.
authors.affiliation: Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: K
authors.initials: K
authors.lastname: Flesch
authors.affiliation: Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: T
authors.initials: T
authors.lastname: Kremeyer
authors.affiliation: Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: O
authors.initials: O
authors.lastname: Schmitz
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: V
authors.initials: V
authors.lastname: Soukhanovskii
authors.affiliation: Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Wenzel