title: 2D microwave imaging reflectometer electronics.
abstract: A 2D microwave imaging reflectometer system has been developed to visualize electron density fluctuations on the DIII-D tokamak. Simultaneously illuminated at four probe frequencies, large aperture optics image reflections from four density-dependent cutoff surfaces in the plasma over an extended region of the DIII-D plasma. Localized density fluctuations in the vicinity of the plasma cutoff surfaces modulate the plasma reflections, yielding a 2D image of electron density fluctuations. Details are presented of the receiver down conversion electronics that generate the in-phase (I) and quadrature (Q) reflectometer signals from which 2D density fluctuation data are obtained. Also presented are details on the control system and backplane used to manage the electronics as well as an introduction to the computer based control program.
authors.affiliation: Electrical & Computer Engineering, University of California, Davis, California 95616, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Spear
authors.affiliation: Electrical & Computer Engineering, University of California, Davis, California 95616, USA.
authors.forename: C W
authors.initials: CW
authors.lastname: Domier
authors.affiliation: Electrical & Computer Engineering, University of California, Davis, California 95616, USA.
authors.forename: X
authors.initials: X
authors.lastname: Hu
authors.affiliation: Electrical & Computer Engineering, University of California, Davis, California 95616, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Muscatello
authors.affiliation: Electrical & Computer Engineering, University of California, Davis, California 95616, USA.
authors.forename: X
authors.initials: X
authors.lastname: Ren
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Tobias
authors.affiliation: Electrical & Computer Engineering, University of California, Davis, California 95616, USA.
authors.forename: N C
authors.initials: NC
authors.lastname: Luhmann