title: Development of internal magnetic probe for current density profile measurement in Versatile Experiment Spherical Torus.
abstract: An internal magnetic probe using Hall sensors to measure a current density profile directly with perturbation of less than 10% to the plasma current is successfully operated for the first time in Versatile Experiment Spherical Torus (VEST). An appropriate Hall sensor is chosen to produce sufficient signals for VEST magnetic field while maintaining the small size of 10 mm in outer diameter. Temperature around the Hall sensor in a typical VEST plasma is regulated by blown air of 2 bars. First measurement of 60 kA VEST ohmic discharge shows a reasonable agreement with the total plasma current measured by Rogowski coil in VEST.
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: J W
authors.initials: JW
authors.lastname: Lee
authors.affiliation: SNU Division of Graduate Education for Sustainabilization of Foundation Energy, Seoul National University, Seoul 151-744, South Korea.
authors.forename: B K
authors.initials: BK
authors.lastname: Jung
authors.affiliation: SNU Division of Graduate Education for Sustainabilization of Foundation Energy, Seoul National University, Seoul 151-744, South Korea.
authors.forename: K J
authors.initials: KJ
authors.lastname: Chung
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Hwang