title: Alternative optical concept for electron cyclotron emission imaging.
abstract: The implementation of advanced electron cyclotron emission imaging (ECEI) systems on tokamak experiments has revolutionized the diagnosis of magnetohydrodynamic (MHD) activities and improved our understanding of instabilities, which lead to disruptions. It is therefore desirable to have an ECEI system on the ITER tokamak. However, the large size of optical components in presently used ECEI systems have, up to now, precluded the implementation of an ECEI system on ITER. This paper describes a new optical ECEI concept that employs a single spherical mirror as the only optical component and exploits the astigmatism of such a mirror to produce an image with one-dimensional spatial resolution on the detector. Since this alternative approach would only require a thin slit as the viewing port to the plasma, it would make the implementation of an ECEI system on ITER feasible. The results obtained from proof-of-principle experiments with a 125 GHz microwave system are presented.
authors.affiliation: Department of Physics, University of California Berkeley, Berkeley, California 94720, USA.
authors.forename: J X
authors.initials: JX
authors.lastname: Liu
authors.affiliation: Department of Physics, College of William and Mary, Williamsburg, Virginia 23185, USA.
authors.forename: T
authors.initials: T
authors.lastname: Milbourne
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: M
authors.initials: M
authors.lastname: Bitter
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: L
authors.initials: L
authors.lastname: Delgado-Aparicio
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: A
authors.initials: A
authors.lastname: Dominguez
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: P C
authors.initials: PC
authors.lastname: Efthimion
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: K W
authors.initials: KW
authors.lastname: Hill
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Kramer
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: C
authors.initials: C
authors.lastname: Kung
authors.affiliation: Department of Physics, University of California Los Angeles, Los Angeles, California 90095, USA.
authors.forename: S
authors.initials: S
authors.lastname: Kubota
authors.affiliation: Department of Electrical Engineering, University of Stuttgart, Stuttgart, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Kasparek
authors.affiliation: Department of Physics, Chongqing University, Chongqing 400044, China.
authors.forename: J
authors.initials: J
authors.lastname: Lu
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: N A
authors.initials: NA
authors.lastname: Pablant
authors.affiliation: Ulsan National Institute of Science and Technology, Ulsan 689-798, South Korea.
authors.forename: H
authors.initials: H
authors.lastname: Park
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA.
authors.forename: B
authors.initials: B
authors.lastname: Tobias