Title :
Diagnostic upgrades on MTX
Author :
Nilson, D. ; Casper, T. ; Foote, J. ; Lasnier, C. ; Lopez, P. ; Rice, B. ; Stever, R. ; Hoshino, K. ; Odajima, K. ; Oda, T. ; Mizuno, K.
Author_Institution :
Lawrence Livermore Nat. Lab., CA, USA
fDate :
30 Sep-3 Oct 1991
Abstract :
The MTX (Microwave Tokamak Experiment) experiment diagnostic capabilities were upgraded, with the addition of five new diagnostics. A second beamline was added on the existing Michelson ECE waveguide to accommodate the new polychromator. This provides four orders of magnitude higher time resolution (1-2 μs) than the Michelson, with an improved spectral resolution (5 GHz) using up to nine separate channels. A four-channel ECE microwave receiver system using both an inside and an outside horn placed on the inner tokamak makes it possible to measure the hot electron emission generated from gyrotron and FEL (free-electron-laser) heating. A 15-channel interferometer on MTX was upgraded with the addition of polarimetry to provide measurements of the poloidal magnetic field. This upgrade uses a technique that determines the Faraday rotation by measuring the phase of a rapidly rotating polarization ellipse. The high-speed rotating optics (>60 K rpm) used to produce this state of polarization is reviewed. A two-channel O-mode reflectometer spanning 75-105 GHz is being added to measure the movements of the cutoff layer. By varying the frequency of this diagnostic, one can measure fluctuations deep within the plasma. A particle probe diagnostic currently under construction will measure the FEL electric field strength inside the tokamak plasma
Keywords :
Tokamak devices; fusion reactor instrumentation; plasma diagnostic techniques; plasma diagnostics by laser beam; FEL electric field; Faraday rotation; Michelson ECE waveguide; Microwave Tokamak Experiment; diagnostic capabilities; four-channel ECE microwave receiver system; gyrotron; hot electron emission; polarimetry; polychromator; spectral resolution; two-channel O-mode reflectometer; Electromagnetic heating; Electron emission; Magnetic field measurement; Microwave measurements; Optical interferometry; Optical polarization; Optical waveguides; Plasma diagnostics; Plasma measurements; Tokamaks;
Conference_Titel :
Fusion Engineering, 1991. Proceedings., 14th IEEE/NPSS Symposium on
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0132-3
DOI :
10.1109/FUSION.1991.218655