scholarly journals A Compact Two-Frequency Notch Filter for Millimeter Wave Plasma Diagnostics

2020 ◽  
Vol 41 (7) ◽  
pp. 741-749
Author(s):  
D. Wagner ◽  
W. Kasparek ◽  
F. Leuterer ◽  
F. Monaco ◽  
T. Ruess ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Electron Cyclotron Resonance ◽  
Narrow Band ◽  
Rectangular Cross Section ◽  
Notch Filter ◽  
Magnetic Confinement ◽  
Electron Cyclotron Resonance Heating ◽  
Plasma Fusion ◽  
Stray Radiation ◽  
Very High

AbstractSensitive millimeter wave diagnostics in magnetic confinement plasma fusion experiments need protection from gyrotron stray radiation in the plasma vessel. Modern electron cyclotron resonance heating (ECRH) systems take advantage of multi-frequency gyrotrons. This means that the frequency band of some millimeter wave diagnostics contains more than one narrow-band gyrotron-frequency line, which needs to be effectively suppressed. A compact standard waveguide notch filter based on coupled waveguide resonators with rectangular cross-section is presented which can provide very high suppression of several gyrotron frequencies and has low insertion loss of the passband.

scholarly journals Gyrotron: The most Suitable Millimeter-Wave Source for Heating of Plasma in Tokamak

2021 ◽  
Author(s):  
Santanu Karmakar ◽  
Jagadish C. Mudiganti
Keyword(s):  
Millimeter Wave ◽  
Electron Cyclotron Resonance ◽  
Plasma Heating ◽  
Electron Cyclotron ◽  
Current Drive ◽  
Electron Cyclotron Resonance Heating ◽  
Wave Source ◽  
Microwave Source ◽  
Millimeter Wave Source ◽  
Traveling Wave Tubes

In this chapter, brief outline is presented about gyro-devices. Gyro-devices comprise of a family of microwave devices and gyrotron is one among those. Various gyro devices, namely, gyrotron, gyro-klystron and gyro traveling-wave tubes (gyro-TWT) are discussed. Gyrotron is the only microwave source which can generate megawatt range of power at millimeter-wave and sub-millimeter-wave frequency. Gyrotron is the most suitable millimeter wave source for the heating of plasma in the Tokamak for the controlled thermoneuclear fusion reactors. This device is used both for the electron cyclotron resonance heating (ECRH) as well as for the electron cyclotron current drive (ECCD). In this chapter, the basic theory of gyrotron operation are presented with the explanation of various sub-systems of gyrotron. The applications of gyrotrons are also discussed. Also, the present state-of-the-art worldwide scenario of gyrotrons suitable for plasma heating applications are presented in details.

A Low-Noise, High-Gain Quasi-Millimeter-Wave Receiver MMIC with a Very High Degree of Integration Using 3D-MMIC Technology

2011 ◽  
Vol E94-C (10) ◽  
pp. 1548-1556 ◽  
Author(s):  
Takana KAHO ◽  
Yo YAMAGUCHI ◽  
Kazuhiro UEHARA ◽  
Kiyomichi ARAKI
Keyword(s):  
Millimeter Wave ◽  
High Gain ◽  
Low Noise ◽  
High Degree ◽  
Very High ◽  
Millimeter Wave Receiver

Direct Inverse Control for ECRH Voltage Based on ICA-CMAC

2011 ◽  
Vol 268-270 ◽  
pp. 1755-1758
Author(s):  
Xiao Ping Luo ◽  
Peng Ying Du ◽  
Ying Qi Ge
Keyword(s):  
Nonlinear System ◽  
Power Supply ◽  
Cyclotron Resonance ◽  
Control Experiment ◽  
Electron Cyclotron Resonance ◽  
Electron Cyclotron Resonance Heating ◽  
Quick Response ◽  
High Voltage Power Supply ◽  
Inverse Control ◽  
Intelligent Controller

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.

Understanding core tungsten (W) transport and control in an improved high-performance fully non-inductive discharge on EAST

2021 ◽  
Author(s):  
Shengyu Shi ◽  
Jiale Chen ◽  
Clarisse Bourdelle ◽  
Xiang Jian ◽  
Tomas Odstrcil ◽  
...  
Keyword(s):  
Density Profile ◽  
Turbulent Diffusion ◽  
High Performance ◽  
Electron Cyclotron Resonance ◽  
Transport Coefficients ◽  
Linear Instability ◽  
Electron Cyclotron Resonance Heating ◽  
Plasma Parameters ◽  
Turbulent Diffusion Coefficient ◽  
Inductive Discharge

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.

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