A one-channel microwave reflectometer is used to measure the electron densityprofile in a low-density plasma experiment (n_e < 0.27 x 10^(19) m^(-3)) sustained by 2.45 GHzlower hybrid current drive (LHCD) on TRIAM-...A one-channel microwave reflectometer is used to measure the electron densityprofile in a low-density plasma experiment (n_e < 0.27 x 10^(19) m^(-3)) sustained by 2.45 GHzlower hybrid current drive (LHCD) on TRIAM-1M. In order to remove the effect of phase runawayphenomena, a step-like frequency-sweeping way is used and a special phase analysis technique isintroduced. The density profile is reconstructed in TRIAM-1M with the swept frequency ranged from 6GHz to 15 GHz. The corresponding cutoff density is from (0.045 ～ 0.28) x 10^(19) m^(-3) in theordinary polarization mode. The results are in good agreement with the measurements from amulti-channel 2 mm-wavelength interferometer.展开更多
A new electron density profile reconstruction procedure based on the PARK-matrix method has been firstly exploited for the multi-chord formic acid（HCOOH, λ=432.5 μm） laser interferometry system on the HL-2A tokama...A new electron density profile reconstruction procedure based on the PARK-matrix method has been firstly exploited for the multi-chord formic acid（HCOOH, λ=432.5 μm） laser interferometry system on the HL-2A tokamak. According to the geometric coordinates of the magnetic surfaces reconstructed by the CF（current fitting） code and the assumption that the electron density between two adjacent magnetic surfaces is a constant, the local electron density is calculated layer by layer, and the electron density profile n_e（Z） can be determined, as well as the density profile n_e（R）. The simulation result indicates that the error of the PARK-matrix method is acceptable for the four-chord HCOOH laser interferometer. In the applications, it shows that the reconstructed electron density profile agrees well with the microwave reflectometry measurement,and the sawtooth reversion radius is consistent with that deduced from the soft X-ray signals.Meanwhile, the electron density profiles with electron cyclotron resonance heating（ECRH） and supersonic molecular beam injection（SMBI） are also reconstructed and analyzed.展开更多
文摘A one-channel microwave reflectometer is used to measure the electron densityprofile in a low-density plasma experiment (n_e < 0.27 x 10^(19) m^(-3)) sustained by 2.45 GHzlower hybrid current drive (LHCD) on TRIAM-1M. In order to remove the effect of phase runawayphenomena, a step-like frequency-sweeping way is used and a special phase analysis technique isintroduced. The density profile is reconstructed in TRIAM-1M with the swept frequency ranged from 6GHz to 15 GHz. The corresponding cutoff density is from (0.045 ～ 0.28) x 10^(19) m^(-3) in theordinary polarization mode. The results are in good agreement with the measurements from amulti-channel 2 mm-wavelength interferometer.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2014GB109001)National Natural Science Foundation of China(Nos.11505053 and 11275059)
文摘A new electron density profile reconstruction procedure based on the PARK-matrix method has been firstly exploited for the multi-chord formic acid（HCOOH, λ=432.5 μm） laser interferometry system on the HL-2A tokamak. According to the geometric coordinates of the magnetic surfaces reconstructed by the CF（current fitting） code and the assumption that the electron density between two adjacent magnetic surfaces is a constant, the local electron density is calculated layer by layer, and the electron density profile n_e（Z） can be determined, as well as the density profile n_e（R）. The simulation result indicates that the error of the PARK-matrix method is acceptable for the four-chord HCOOH laser interferometer. In the applications, it shows that the reconstructed electron density profile agrees well with the microwave reflectometry measurement,and the sawtooth reversion radius is consistent with that deduced from the soft X-ray signals.Meanwhile, the electron density profiles with electron cyclotron resonance heating（ECRH） and supersonic molecular beam injection（SMBI） are also reconstructed and analyzed.
