The aim of WEST experiments is to master long plasma pulses (1000 s) and expose ITER-like tungsten tiles to power fluxes up to 10 MW/m2. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, an upgraded ECRH system, with a power capability of 3MW/1000s at a frequency of 105 GHz for a central power absorption, is planned for operation in 2023.
The previous...
COMPASS Upgrade, a medium-sized tokamak is under design at the Institute of Plasma Physics in Prague [1]. Due to wide range of operation scenarios with toriodal magnetic field up to 5 T and expected high density during H-mode ($ I_{\mathrm{p}}= 2 \ \mathrm{MA},\ n_{\mathrm{GW}} = 8.7\cdot 10^{20}\ \mathrm{m^{-3}}$), the design of suitable solution is a challenging task. \
The ECRH system...
The DTT tokamak [1], whose construction is starting in Frascati (Italy), will be equipped with an ECRH system of 16 MW for the first plasma and with a total of 32 gyrotrons (170 GHz, ≥ 1 MW, 100s), organized in 4 clusters of 8 units each in the final design stage. To transmit this large number of power beams from the Gyrotron Hall to the Torus Hall Building a Quasi-Optical (QO) approach has...
For its initial research phase, the JT-60SA tokamak will be equipped with four gyrotrons units delivering up to 3 MW at 110 GHz to the plasma. Together with 6 MW of P-NBI and 10 MW of N-NBI the ECRF power will be used to sustain and control stable operation at high current with a lower single null CFC divertor plasma configuration. The development of the current ramp-up up to full-current...
The UK's Spherical Tokamak for Energy Production (STEP) design program aims at demonstrating the ability to achieve a net electrical gain from fusion reactions in a magnetically confined plasma under reactor relevant conditions. A key aspect for a successful design of a Tokamak reactor is the minimization of the recirculating power needed to maintain plasma operation, dominated by the power...
A fast scan Fourier transform Michelson interferometer system has been installed on SST-1 tokamak. The diagnostic determines electron temperature profile and its evolution by measuring electron cyclotron emissions (ECE) from plasma. This is the first diagnostic on SST-1 to probe higher harmonics of the ECE radiations in 70-500 GHz frequency range. During plasma operation, every 17 ms the...
The diode-type gyrotrons are used in the EAST ECRH system[1]. The anode is one of the main components of the gyrotron[2]. We can control the output power of RF waves by changing the anode voltage. An anode voltage control system was developed based on the ethernet CompactDAQ chassis NI-cDAQ-9185[3]. The anode voltage can be controlled up to 30 kV, and the maximum current is 100 mA. The maximum...
The suite of codes to model the electron cyclotron heating (ECH) profile on the DIII-D tokamak has been extended to follow the EC waves (110 GHz, second harmonic) over multiple bounces, allowing quantitative comparisons with experimental measurements in low absorption regimes for a number of purposes. First, the EC wave polarization has been checked by launching the waves radially at the...
The ECRH system formerly used in Tore Supra is being upgraded to start on WEST in 2023, at a power level of 1 MW and frequency of 105 GHz. Its ultimate 3 MW/1000s capability is expected to enlarge the WEST operational domain by increasing margins with respect to H-mode access, and by providing additional flexibility in terms of achievable scenarios using impurity and/or MHD control. This...
Recent experiments on the DIII-D tokamak show access to edge localized mode (ELM) suppression with resonant magnetic perturbations (RMP) is affected by electron cyclotron heating (ECH) and current drive (ECCD) in the plasma edge region (rho~0.9-0.95). It is found that application of co-Ip ECCD can lead to the return of edge localized modes (ELMs), while heating the plasma with matching ECH...
Tokamak COMPASS Upgrade, a medium-sized device is under the design at the Institute of Plasma Physics in Prague. COMPASS Upgrade will operate with a high magnetic field $B_{\mathrm{T}}=5$~T, flat top current up to $2$ MA with correspondent $n_{GW}=8.7 \cdot 10^{20}$ m$^{-3}$. The baseline heating system will be composed of NBI heating system with a power up to $6$ MW. To get the ability to...
Wendestein 7-X (W7-X) is a high iota, low shear optimized stellarator concerning magnetic field geometry with a scientific objective to attain 30 min of detached steady-state plasmas. The electron cyclotron emission (ECE) at W7-X is measured by a heterodyne radiometer [1] in the spectral range of the X2 emission from 126 to 162 GHz and by a Martin-Puplett interferometer [2] in the spectral...
The second incarnation of the Synthetic Aperture Microwave Imager (SAMI-2) is a tokamak diagnostic operating in the frequency range 20-40 GHz with up to 30 dual-polarisation receiving antennas amd 2 transmitting antennas.
SAMI-2 has two core missions [references to work with the original SAMI]:
(a) imaging spontaneous emission of electron Bernstein waves converted to electromagnetic waves...
The Divertor Tokamak Test (DTT) facility [1] is under construction in Italy with focus on power and particle exhaust and it will reach the condition of 15 MW/m power flow outwards through the separatrix by coupling up to 45 MW of auxiliary heating power to the plasma. To achieve this goal, the selected heating systems are Electron Cyclotron Resonant Heating (ECRH), Ion Cyclotron Resonant...
In 2019, a 105 GHz/500 kW/1 s ECRH system has been established on J-TEXT tokamak to improve plasma parameters and broaden operation range. This system consists of traditional subsystems including a gyrotron from GYCOM, a transmission line based on the corrugated waveguides, and a quasi-optical launcher, where the injection angle of the beam can be adjusted by the steerable mirror integrated in...
In collaboration with IPP Greifswald, an industrial gyrotron operating at 140 GHz with 1.5 MW RF power for the upgrade of the ECRH system of the W7-X stellarator is under development at KIT. A quasi-optical (q.o.) mode converter has been designed for this 1.5 MW gyrotron, operating in the TE28,10 mode. The q.o. mode converter consists of a mirror-line conical launcher [1] and three mirrors...
