Development of electron cyclotron emission imaging system on the HL-2A tokamak.

A 2D electron cyclotron emission imaging (ECEI) system has been developed for measurement of electron temperature fluctuations in the HL-2A tokamak. It is comprised of a front-end 24 channel heterodyne imaging array with a tunable RF range spanning 75-110 GHz, and a set of back-end ECEI electronics that together generate 24 × 8 = 192 channel images of the 2nd harmonic X-mode electron cyclotron emission from the HL-2A plasma. The simulated performance of the local oscillator (LO) optics and radio frequency (RF) optics is presented, together with the laboratory characterization results. The Gaussian beams from the LO optics are observed to properly cover the entire detector array. The ECE signals from the plasma are mixed with the LO signal in the array box, then delivered to the electronics system by low-loss microwave cables, and finally to the digitizers. The ECEI system can achieve temporal resolutions of ~μs, and spatial resolutions of 1 cm (radially) and 2 cm (poloidally).

[1]  Ming Xu,et al.  Electron Cyclotron Emission Imaging on the EAST Tokamak , 2011 .

[2]  Chao-Chun Chen,et al.  Transmission of Microwave Through Perforated Flat Plates of Finite Thickness , 1973 .

[3]  C. Domier,et al.  Development of KSTAR ECE imaging system for measurement of temperature fluctuations and edge density fluctuations. , 2010, The Review of scientific instruments.

[4]  M. Hirsch,et al.  Heterodyne methods in millimetre wave plasma diagnostics with applications to ECE, interferometry and reflectometry , 1997 .

[5]  Calvin Domier,et al.  Electron cyclotron emission imaging diagnostic system for Rijnhuizen Tokamak Project , 1999 .

[6]  Advancements in electron cyclotron emission imaging demonstrated by the TEXTOR ECEI diagnostic upgrade. , 2009, The Review of scientific instruments.

[7]  C. Domier,et al.  The next generation of electron cyclotron emission imaging diagnostics (invited). , 2008, The Review of scientific instruments.

[8]  I G J Classen,et al.  Commissioning of electron cyclotron emission imaging instrument on the DIII-D tokamak and first data. , 2010, The Review of scientific instruments.

[9]  W. Park,et al.  Tomography of full sawtooth crashes on the Tokamak Fusion Test Reactor , 1996 .

[10]  A. Donné,et al.  2D electron cyclotron emission imaging at ASDEX Upgrade (invited). , 2010, The Review of scientific instruments.

[11]  K. Kawahata,et al.  Development of ECE Imaging System on LHD , 2007 .

[12]  Chao-Chun Chen,et al.  Diffraction of Electromagnetic Waves by a Conducting Screen Perforated Periodically with Holes , 1971 .

[13]  K. Kawahata,et al.  Electron cyclotron emission imaging on a Large Helical Device , 2003 .

[14]  D. Brower,et al.  Hybrid electron cyclotron emission imaging array system for Texas experimental tokamak upgrade , 1997 .

[15]  N. Luhmann,et al.  One-Dimensional Vertical ECEI Diagnostic for HT-7 Tokamak , 2006 .

[16]  C. Domier,et al.  Electron cyclotron emission imaging diagnostic on TEXTOR , 2001 .