µ-wave solid state technology
Prof. N.C. Luhmann,
cyclotron emission imaging (ECEI) is one of the many microwave diagnostics
that the DMRC develops and fabricates. Shown above are sample data from the
ECEI system on the DIII-D tokamak located at
General Atomics in San Diego, CA. ECEI is well-suited for diagnosing MHD
activity and interactions across multiple scales. The particular examples
above are images from a single DIII-D discharge comparing the fine-scale
structure of an Alfvén eigenmode
(left) to meso-scale perturbations due to a
core-localized kink instability (right). Covering a large region of the
plasma in 2D, ECEI enables reconstruction of helically symmetric structures
in the entire poloidal plane.
imaging of the sawtooth crash at the inboard, or
high field side, shows that thermal transport occurs along a localized
conduction channel, consistent with a model for local magnetic
reconnection. The hot plasma is carried leftward, across the temperature
inversion radius, and ejected from the tokamak
core. The image is unambiguous, composed of localized measurements, and is
not subject to the uncertainties associated with the inversion of line
systems acquire data with micro-second resolution, allowing for accurate
discrimination among coupled and closely spaced eigenmodes.
In this case, the linear superposition of two separate Alfvén
eigenmodes (left 2 panels) produces a complicated
structure (right panel). But, the quality of ECEI data allows these modes
to be imaged separately for better understanding of their linear and
non-linear stability properties.
- Dr. Chris Muscatello Invited Talk at the 20th High-Temperture Plasma Diagnostics Conference entitled "Simultaneous 2D Imaging of Temperature and Density Fluctuations Using the DIII-D Combined ECE-Imaging/Millimeter-Wave Imaging Reflectometer Diagnostic," Atlanta, Georgia, June 1-5, 2014.
- 20th High-Temperture Plasma Diagnostics Conference entitled "346 GHz Source for Plasma Diagnostic Applications," R. Barchfeld, P. Popovic, X. Tang, L. Yue, F. Zhang, R. Letizia, C. Paoloni, C.W. Domier, tt, N.C. Luhmann, Jr., Atlanta, Georgia, June 1-5, 2014.
- 20th High-Temperture Plasma Diagnostics Conference entitled "Installation Plans for the Far Infrared Tangential Interferometer/Polarimeter (FIReTIP) System on NSTX-U,"M. Sohrabi, R. Barchfeld, C.W. Domier, C.M. Muscatello, P. Riemenschneider, E.R. Scott, N.C. Luhmann, Jr., (University of California, Davis), Y. Ren, R. Kaita, M. Kalish, (Princeton Plasma Physics Laboratory,) Atlanta, Georgia, June 1-5, 2014.
N.C. Luhmann, Jr. Akazaki Lecture: 16th International Symposium Laser Aided Plasma Diagnostics, Madison WI, September 22-25, 2013.
N.C. Luhmann, Jr. was awarded the 2012 John R. Pierce Award for Excellence in Vacuum Electronics: "For Outstanding Contributions and Leadership in the Field of Vacuum Electronics as a Scientist, Engineer, and Educator."
- Invited Talk: Millimeter-Wave to THz Vacuum Electron Beam Devices, A. Baig, D. Gamzina, J. Zhao, C. Domier, L. Barnett, N. Luhmann, Jr., IEEE 2012 Asia Pacific Microwave Conference (APMC).
- Dr. B.J. Tobias was awarded the Allen G. John Marr Prize Distinguished Dissertation Award.
- A Baig, "Simulation Analysis of Nano-CNC Fabricated 220 GHz Ultra Wide Band TWTA," 13th International Vacuum Electronics Conference, April 24-26, 2012.
- R. Barchfeld, "Nano CNC Milling of Two Different Designs of 0.22 THz TWT Circuits," 13th International Vacuum Electronics Conference, April 24-26, 2012.
- Dr. J. Zhao, "Scandate-Added Tungsten Dispenser Cathode Fabrication for 220 GHz Sheet Beam Traveling Wave Tube Amplifier,"13th International Vacuum Electronics Conference, April 24-26, 2012.
Dr. B.J. Tobias, (Invited Talk), "ECE-Imaging of the H-Mode Pedestal," 19th Topical Conference High-Temperature Plasma Diagnostics, May 6-10, 2012."
- Prof. N.C. Luhmann, Jr., "Electron Cyclotron Emission Imaging on KSTAR," 19th Topical Conference High-Temperature Plasma Diagnostics, May 6-10, 2012.
- Dr. B.J. Tobias, "Microwave Imaging Reflectometry from Concept to Construction: The Role of Modeling and Laboratory Characterization in Diagnostic Development," 39th International Conference on Plasma Science, July 8-12, 2012.