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Experiments on TEXTOR have successfully demonstrated the proof of principle of using Electron Cyclotron Emission (ECE) measured along the Electron Cyclotron Resonance Heating (ECRH) line-of-sight for the control of magnetohydrodynamic (MHD) modes. This work, which was done with a quasi-optical system, motivates the further development and implementation of a similar, but in-waveguide system for detection...
The multi-frequency Electron Cyclotron Heating (ECRH) system at the ASDEX Upgrade tokamak employs depressed collector gyrotrons, step-tunable in the range 105-140 GHz. The system is equipped with a fast steerable launcher allowing for remote steering of the ECRH beam during the plasma discharge. The polarization can be controlled in a feed-forward mode.
It is proposed to provide the Electron Cyclotron Emission (ECE) feedback signal for MHD control experiments along the ECRH line-of sight. Experiments on TEXTOR have demonstrated a proof of principle motivate the further development and the implementation of such an ECCD aligned ECE system for NTM control in larger fusion machines. Implementation of such a system on ASDEX-Upgrade, based on waveguides...
A new ECRH system is currently under construction at the ASDEX Upgrade tokamak. It employs for the first time depressed collector gyrotrons, step-tunable in the range 105-140 GHz. In its final stage it will consist of 4 gyrotrons with a total output power of 4 MW and a pulse length of 10 s. In this paper we describe recent extensions of the system and some experimental results.
Currently, a new multi-frequency ECRH system is under construction at the ASDEX Upgrade Tokamak experiment. This system employs, for the first time in a fusion device, multi-frequency gyrotrons, step-tunable in the range 105-140 GHz. The system includes fast steerable launchers at the front end that will allow for very localized feedback controlled power deposition in the plasma.
Summary form only given. A critical need exists for confined fast ion diagnostics in tokamak fusion experiments, particularly for fusion product alpha particles in ITER and future fusion burning experiments. To develop this diagnostic capability and in support of current fast ion plasma physics research, collective Thomson scattering (CTS) diagnostics have been implemented at TEXTOR and ASDEX Upgrade...
Summary form only given. The first two-frequency GYCOM gyrotron Odissey-1 has been installed and put into operation in the new multi-frequency ECRH system at the ASDEX Upgrade tokamak experiment. It works at 105 GHz and 140GHz with output power 610kW and 820kW respectively at a pulse length of 10s. A further extension of the system with 3 more gyrotrons is underway. These gyrotrons will be step-tunable...
In the TJ-II stellarator, the plasmas are created and heated by two 53.2 GHz gyrotrons, each of them delivering 300 kW. The power is transmitted to the plasma by two quasi-optical transmission lines (QTL1 and QTL2). The last mirror of each line is a steerable mirror located inside the vacuum vessel, which allows for perpendicular and oblique injection. In order to have a good coupling of the X mode,...
The power deposition in the plasma is primarily determined by the magnetic field B(r). For a single frequency ECRH system this has the consequence that for central heating the magnetic field is no longer a free parameter. However, for plasmas with different plasma currents or different equilibria, the magnetic field should be a free parameter in order to operate at a reasonable edge safety factor...
The first two-frequency GYCOM gyrotron Odissey-1 has been installed and put into operation in the new multi-frequency ECRH system at the ASDEX Upgrade tokamak experiment.
The design of the optical (q.o.) RF output system for the first industrial prototype of the European 170 GHz, 2 MW, CW coaxial cavity gyrotron for electron cyclotron heating and current drive in ITER has been verified at low power level. Results of measurements with a high quality TE34,19-mode generator are in good agreement with the design calculation and is presented in the following paper
Summary form only given. The power deposition in ECRH (electron cyclotron resonance heating) of fusion plasmas is primarily determined by the magnetic field. For a single frequency ECRH system this has the consequence that for central heating the magnetic field is no longer a free parameter. However, for tokamak plasmas with different plasma currents or different equilibria, the magnetic field should...
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