Electron cyclotron emission measurements in JT-60U

Real-time measurement and feedback control of ion temperature profile and toroidal rotation using fast CXRS system in JT-60U

“…In these high performance plasmas, the pressure, rotation and current profiles play the critical roles in determining transport [1][2][3] and MHD stability [4][5][6][7] interacting with each other [8]. Therefore, the development of the real-time control system [9][10][11][12][13][14] for these parameters is essentially important in sustaining high performance plasmas. For example, it is generally accepted that the control of pressure and current profiles is useful to stabilize the neoclassical tearing mode (NTM) [4] and the edge localized mode (ELM) [15].…”

“…ion and electron). An electron density control has been demonstrated by an interferometer with gas-puffing [9], and an electron temperature control has also been carried out by a fast electron cyclotron emission (ECE) radiometer with neutral beams (NBs) [10].…”

Chapter 3: Microwave Diagnostics

“…blackbody sources. 61,62 More recently, by ramping the toroidal field and detecting coherent features in the measurement spectrum due to small errors in the calibration, researchers at the JET tokamak have been able to reduce the residual systematic, frequency errors in the absolute calibration~Х5 to 10% level!, thereby improving the relative accuracy. 63,64 Application of this technique has improved both the smoothness and the symmetry of the T e profiles.…”

“…All three types of detection are employed. 62,[65][66][67][68] Table II lists the specifications of the three separate instruments. An inspection of Table II reveals their different characteristics.…”

Neutron Emission Profile Measurement and Fast Charge Exchange Neutral Particle Flux Measurement for Transport Analysis of Energetic Ions in JT-60U

“…The effect of sawtooth on the redistribution of energetic ions in tokamaks has been studied both experimentally [31] and theoretically [32]. Figures 14 (a) and (b) show the time traces of the electron temperature measured from the ECE measurement [33]. The sawtooth electron temperature variation in the center of the plasma as well as the inverted behavior which occurs in the outer region were observed.…”