title: Design and installation of a ferromagnetic wall in tokamak geometry.
abstract: Low-activation ferritic steels are leading material candidates for use in next-generation fusion development experiments such as a prospective component test facility and DEMO power reactor. Understanding the interaction of plasmas with a ferromagnetic wall will provide crucial physics for these facilities. In order to study ferromagnetic effects in toroidal geometry, a ferritic wall upgrade was designed and installed in the High Beta Tokamak-Extended Pulse (HBT-EP). Several material options were investigated based on conductivity, magnetic permeability, vacuum compatibility, and other criteria, and the material of choice (high-cobalt steel) is characterized. Installation was accomplished quickly, with minimal impact on existing diagnostics and overall machine performance, and initial results demonstrate the effects of the ferritic wall on plasma stability.
authors.affiliation: Columbia University Plasma Physics Laboratory, Columbia University, 102 S.W. Mudd, 500 W. 120th St., New York, New York 10027, USA.
authors.forename: P E
authors.initials: PE
authors.lastname: Hughes
authors.affiliation: Columbia University Plasma Physics Laboratory, Columbia University, 102 S.W. Mudd, 500 W. 120th St., New York, New York 10027, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Levesque
authors.affiliation: Columbia University Plasma Physics Laboratory, Columbia University, 102 S.W. Mudd, 500 W. 120th St., New York, New York 10027, USA.
authors.forename: N
authors.initials: N
authors.lastname: Rivera
authors.affiliation: Columbia University Plasma Physics Laboratory, Columbia University, 102 S.W. Mudd, 500 W. 120th St., New York, New York 10027, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Mauel
authors.affiliation: Columbia University Plasma Physics Laboratory, Columbia University, 102 S.W. Mudd, 500 W. 120th St., New York, New York 10027, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Navratil