title: Development of multichannel intermediate frequency system for electron cyclotron emission radiometer on KSTAR Tokamak.
abstract: Plasma experiments on KSTAR are scheduled to start up this year (2008). We have developed an electron cyclotron emission (ECE) radiometer to measure the radial electron temperature profiles in KSTAR experiments. The radiometer system consists, briefly, of two downconversion stages, amplifiers, bandpass filter banks, and video detectors. These components are made commercially or developed in house. The system detects ECE power in the frequency range from 110 to 196 GHz, the detected signal being resolved by means of 48 frequency windows. Before installation of this system on KSTAR, we installed a part of this system on large helical device (LHD) to study the system under similar plasma conditions. In this experiment, the signal amplitude, considered to be proportional to the electron temperature, is measured. The time-dependent traces of the electron temperature measured by this radiometer are in good agreement with those provided by the LHD Michelson spectrometer. The system noise level which limits the minimum measurable temperature (converted to the electron temperature) is about 30 eV.
authors.affiliation: Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga Fukuoka 816-8580, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kogi
authors.forename: Takuya
authors.initials: T
authors.lastname: Sakoda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mase
authors.forename: Naoki
authors.initials: N
authors.lastname: Ito
authors.forename: Yuya
authors.initials: Y
authors.lastname: Yokota
authors.forename: Soichiro
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nagayama
authors.forename: Seung H
authors.initials: SH
authors.lastname: Jeong
authors.forename: Myeun
authors.initials: M
authors.lastname: Kwon
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kawahata