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TJ-II:Electron Cyclotron Emission: Difference between revisions
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Specifies that the ECE system is tuned to receive radiation mainly from the HFS of the plasma
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m (Specifies that the ECE system is tuned to receive radiation mainly from the HFS of the plasma) |
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by means of a 16 channel heterodyne radiometer, | by means of a 16 channel heterodyne radiometer, | ||
covering the frequency range 50–60 GHz, corresponding to the second harmonic of electron cyclotron emission (ECE) in X-mode polarization at a magnetic field of 0.95 T on the plasma axis. | covering the frequency range 50–60 GHz, corresponding to the second harmonic of electron cyclotron emission (ECE) in X-mode polarization at a magnetic field of 0.95 T on the plasma axis. | ||
The measurements are performed from the low field side (LFS) in the horizontal midplane (between [[TJ-II:Sectors|sectors]] C4 and C5, φ = 315°). | The measurements are performed from the low field side (LFS) in the horizontal midplane (between [[TJ-II:Sectors|sectors]] C4 and C5, φ = 315°), but most of the channels receive radiation from the high field side (HFS). In normal operation conditions, the frequency depends on a known way on the magnitude of the magnetic field B. Tuning properly the receiver system, each frequency corresponds to a different value of the major radius ''R'' (according to ''B(R)''). | ||
The system is operated close to the strong [[TJ-II:Electron Cyclotron Resonant Heating|ECR heating source]] (f<sub>ECRH</sub> = 53.2 GHz). | The system is operated close to the strong [[TJ-II:Electron Cyclotron Resonant Heating|ECR heating source]] (f<sub>ECRH</sub> = 53.2 GHz). | ||
To protect the radiometer against stray radiation from the gyrotron, the radiometer band is split into two parts. | To protect the radiometer against stray radiation from the gyrotron, the radiometer band is split into two parts. | ||