title: Electron density profile measurements from hydrogen line intensity ratio method in Versatile Experiment Spherical Torus.
abstract: Electron density profiles of versatile experiment spherical torus plasmas are measured by using a hydrogen line intensity ratio method. A fast-frame visible camera with appropriate bandpass filters is used to detect images of Balmer line intensities. The unique optical system makes it possible to take images of Hαand Hβradiation simultaneously, with only one camera. The frame rate is 1000 fps and the spatial resolution of the system is about 0.5 cm. One-dimensional local emissivity profiles have been obtained from the toroidal line of sight with viewing dumps. An initial result for the electron density profile is presented and is in reasonable agreement with values measured by a triple Langmuir probe.
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: YooSung
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Yue-Jiang
authors.initials: YJ
authors.lastname: Shi
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Jeong-Hun
authors.initials: JH
authors.lastname: Yang
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: SeongCheol
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Young-Gi
authors.initials: YG
authors.lastname: Kim
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Jeong-Jeung
authors.initials: JJ
authors.lastname: Dang
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Seongmoo
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Jungmin
authors.initials: J
authors.lastname: Jo
authors.affiliation: Division of Energy Systems Research, Ajou University, Suwon 442-749, South Korea.
authors.forename: Soo-Ghee
authors.initials: SG
authors.lastname: Oh
authors.affiliation: Department of Nuclear Engineering, Seoul National University, Seoul 151-744, South Korea.
authors.forename: Kyoung-Jae
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