title: Multichannel microwave interferometer with an antenna switching system for electron density measurement in a laboratory plasma experiment.
abstract: This study presents a simple and powerful technique for multichannel measurements of the density profile in laboratory plasmas by microwave interferometry. This technique uses electromechanical microwave switches to temporally switch the connection between multiple receiver antennas and one phase-detection circuit. Using this method, the phase information detected at different positions is rearranged into a time series that can be acquired from a minimum number of data acquisition channels (e.g., two channels in the case of quadrature detection). Our successfully developed multichannel microwave interferometer that uses the antenna switching method was applied to measure the radial electron density profiles in a magnetized plasma experiment. The advantage of the proposed method is its compactness and scalability to multidimensional measurement systems at low cost.
authors.affiliation: Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Eiichirou
authors.initials: E
authors.lastname: Kawamori
authors.affiliation: Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Yu-Hsiang
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga 816-8580, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mase
authors.affiliation: Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Nishida
authors.affiliation: Institute of Space and Plasma Sciences, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: C Z
authors.initials: CZ
authors.lastname: Cheng