26
2 Discharges in Current Large Tokamaks
Fig. 2.8 a The spectrum measured with a VUV spectrometer in a wavelength range of 20–50 nm
and b the expanded spectrum in a wavelength range of 20–35 nm for the high-X-point-configuration
discharge. The thin and the thick lines indicate, respectively, the measured spectrum and the synthesized spectrum with a collisional radiative model with T e = 6.3 eV, n e = 7.8 × 10 20 m −3 , and
nC 4+ /nC 3+ = 4.0 (reprinted with permission from [8])
2.3.2 Probe Measurements
Another important method is to use probes including material test pieces, ions, electrons, laser, and so on. One of the most important is the Langmuir probe to measure
electron temperature, electron density, and electric potential of a plasma. A bolometer
is also a quite important probe to measure power load at the location of its sensor.
Figure 2.11 shows time traces of various parameters for a TEXTOR discharge with
a Mo test limiter, i.e. temperature of the limiter head, intensity of MoI line in front
2 Discharges in Current Large Tokamaks
Fig. 2.8 a The spectrum measured with a VUV spectrometer in a wavelength range of 20–50 nm
and b the expanded spectrum in a wavelength range of 20–35 nm for the high-X-point-configuration
discharge. The thin and the thick lines indicate, respectively, the measured spectrum and the synthesized spectrum with a collisional radiative model with T e = 6.3 eV, n e = 7.8 × 10 20 m −3 , and
nC 4+ /nC 3+ = 4.0 (reprinted with permission from [8])
2.3.2 Probe Measurements
Another important method is to use probes including material test pieces, ions, electrons, laser, and so on. One of the most important is the Langmuir probe to measure
electron temperature, electron density, and electric potential of a plasma. A bolometer
is also a quite important probe to measure power load at the location of its sensor.
Figure 2.11 shows time traces of various parameters for a TEXTOR discharge with
a Mo test limiter, i.e. temperature of the limiter head, intensity of MoI line in front