title: Temperature gradient scale length measurement: A high accuracy application of electron cyclotron emission without calibration.
abstract: Calibration is a crucial procedure in electron temperature (Te) inference from a typical electron cyclotron emission (ECE) diagnostic on tokamaks. Although the calibration provides an important multiplying factor for an individual ECE channel, the parameter ΔTe/Teis independent of any calibration. Since an ECE channel measures the cyclotron emission for a particular flux surface, a non-perturbing change in toroidal magnetic field changes the view of that channel. Hence the calibration-free parameter is a measure of Tegradient. BT-jog technique is presented here which employs the parameter and the raw ECE signals for direct measurement of electron temperature gradient scale length.
authors.affiliation: Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: S
authors.initials: S
authors.lastname: Houshmandyar
authors.affiliation: Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Yang
authors.affiliation: Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: P E
authors.initials: PE
authors.lastname: Phillips
authors.affiliation: Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: W L
authors.initials: WL
authors.lastname: Rowan
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Hubbard
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Rice
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Hughes
authors.affiliation: Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02129, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Wolfe