scholarly journals KIT coaxial gyrotron development: from ITER toward DEMO

2018 ◽  
Vol 10 (5-6) ◽  
pp. 547-555 ◽  
Author(s):  
S. Ruess ◽  
K. A. Avramidis ◽  
M. Fuchs ◽  
G. Gantenbein ◽  
Z. Ioannidis ◽  
...  

Karlsruhe Institute of Technology (KIT) is doing research and development in the field of megawatt-class radio frequency (RF) sources (gyrotrons) for the Electron Cyclotron Resonance Heating (ECRH) systems of the International Thermonuclear Experimental Reactor (ITER) and the DEMOnstration Fusion Power Plant that will follow ITER. In the focus is the development and verification of the European coaxial-cavity gyrotron technology which shall lead to gyrotrons operating at an RF output power significantly larger than 1 MW CW and at an operating frequency above 200 GHz. A major step into that direction is the final verification of the European 170 GHz 2 MW coaxial-cavity pre-prototype at longer pulses up to 1 s. It bases on the upgrade of an already existing highly modular short-pulse (ms-range) pre-prototype. That pre-prototype has shown a world record output power of 2.2 MW already. This paper summarizes briefly the already achieved experimental results using the short-pulse pre-prototype and discusses in detail the design and manufacturing process of the upgrade of the pre-prototype toward longer pulses up to 1 s.

2019 ◽  
Vol 203 ◽  
pp. 04005
Author(s):  
Stefan Illy ◽  
Konstantinos A. Avramidis ◽  
Gerd Gantenbein ◽  
Zisis Ioannidis ◽  
Jianbo Jin ◽  
...  

Coaxial-cavity gyrotrons are microwave sources that can extend the possible power levels of hollow cavity gyrotrons significantly and make them attractive for future fusion experiments and power plants. KIT already demonstrated operation of a modular short-pulse 170 GHz coaxial-cavity gyrotron with an output power of 2.2 MW, operating in the TE34,19 mode. Today’s focus of KIT is the verification of this technology at longer pulses, which will prove the long-pulse capabilities also. At the moment, the current KIT prototype has been extended with cooling capabilities for all critical, highly loaded components of the tube and two new, different electron guns are available for operation. This paper will give an overview about the recent status and the future prospects connected to the coaxial-cavity gyrotron development at KIT, including both experimental and theoretical activities.


2020 ◽  
Vol 185 ◽  
pp. 02016
Author(s):  
Qing Zhou

In this paper, the collimation characteristics of an electron cyclotron resonance heating (ECRH) system with a 28GHz/50kW gyrotron in EXL-50 are studied experimentally. Through using laser trackers and designing matching tooling, test errors of horizontal distances and vertical distances between the transmission line and the flange center are all within 1mm, which are less than 0.4% and 0.07% respectively. In addition, online beam spot test with a 150 ms short pulse from a 28 GHz gyrotron also proves good collimation characteristics of the ECRH system. Finally, spherical plasma is formed through injecting the microwave to the vacuum chamber.


2011 ◽  
Vol 268-270 ◽  
pp. 1755-1758
Author(s):  
Xiao Ping Luo ◽  
Peng Ying Du ◽  
Ying Qi Ge

The negative high-voltage power supply of Electron Cyclotron Resonance Heating (ECRH) is a nonlinear system with serve sensitivity and it is not well for traditional controller to meet restrict demand on stability and quick response. Based on the concept of credit a novel CMAC is designed to accelerate the convergence of traditional CMAC and also is used as an intelligent controller for the power of ECRH based on the idea on direct inverse control. Experiment results show that ICA-CMAC can control the power of ECRH well with shorter settling time and less CPU consumption thus the validity of ICA-CMAC is determined.


2021 ◽  
Author(s):  
Shengyu Shi ◽  
Jiale Chen ◽  
Clarisse Bourdelle ◽  
Xiang Jian ◽  
Tomas Odstrcil ◽  
...  

Abstract The behavior of heavy/high-Z impurity tungsten (W) in an improved high-performance fully non-inductive discharge on EAST with ITER-like divertor (ILD) is analyzed. It is found that W could be well controlled. The causes of no W accumulation are clarified by analyzing the background plasma parameters and modeling the W transport. It turns out that the electron temperature (T_e) and its gradient are usually high while the toroidal rotation and density peaking of the bulk plasma are small. In this condition, the modeled W turbulent diffusion coefficient is big enough to offset the total turbulent and neoclassical pinch, so that W density profile for zero particle flux will not be very peaked. Combining NEO and TGLF for the W transport coefficient and the impurity transport code STRAHL, not only the core W density profile is predicted but also the radiated information mainly produced by W in the experiment can be closely reconstructed. At last, the physics of controlling W accumulation by electron cyclotron resonance heating (ECRH) is illustrated considering the effects of changed T_e by ECRH on ionization balance and transport of W. It shows that the change of ionization and recombination balance by changed T_e is not enough to explain the experimental observation of W behavior, which should be attributed to the changed W transport. By comparing the W transport coefficients in two kinds of plasmas with different T_e profiles, it is shown that high T_e and its gradient play a key role to generate large turbulent diffusion through increasing the growth rate of linear instability so that W accumulation is prevented.


2013 ◽  
Vol 397-400 ◽  
pp. 157-161
Author(s):  
Wei Wei Zhang ◽  
Xiao Song Wang ◽  
Shi Jian Yuan ◽  
Zhong Ren Wang

For a cylinder-beam integrated hydraulic press (CBIHP), the hydraulic cylinder is also functioned as an upper beam. It is the key structural component that outputs the driving force to forge parts. Compared with the traditional three-beam and four-column hydraulic press which has a cylindrical hydraulic cylinder, the structure and force distribution are significantly different for CBIHP. It is able to have higher nominal force and larger section of plunger which the pressure is applied on when the contour geometric dimension is the same. Also, CBIHP has lighter weight and larger section modulus when the nominal force is the same than the traditional hydraulic press. Finally, a 6300KN cylinder-beam integrated hydraulic press, which is the first CBIHP in the world and designed by Harbin Institute of Technology (HIT) in 2012, is also introduced in this paper. It can be seen from the results of numerical simulation for the CBIHP that both of the stresses and displacements on the press in the loading process are allowable.


2005 ◽  
Vol 47 (2) ◽  
pp. 108-118 ◽  
Author(s):  
E. Westerhof ◽  
J. A. Hoekzema ◽  
G. M. D. Hogeweij ◽  
R. J. E. Jaspers ◽  
F. C. Schüller ◽  
...  

2014 ◽  
Vol 9 (2) ◽  
pp. 13-21
Author(s):  
Aleksandr Solomakhin ◽  
Petr Bagryansky ◽  
Yuriy Kovalenko ◽  
Valeriy Savkin ◽  
Dmitriy Yakovlev

Electron cyclotron resonance plasma heating (ECRH) system has been recently installed on the gas dynamic trap (GDT) magnetic mirror. Two microwave beams are injected into the plasma at an angle of 36° with respect to the machine axis in a form of extraordinary (X) waves which are subsequently absorbed in the first harmonic cyclotron resonance. Each microwave beam is generated by a Buran-A type 450 kW/54.5 GHz gyrotron. The article reports on the first microwave injection experiments with limited total power of 300 kW. Adjustment of experimental conditions and magnetic field reconfiguration resulted in an increased diamagnetic signal, electron temperature and other plasma parameters


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