Outline of a theory of lower-hybrid wave absorption

1993 ◽  
Vol 50 (2) ◽  
pp. 251-266
Author(s):  
E. Canobbio ◽  
R. Croci
Keyword(s):  
Homogeneous Magnetic Field ◽  
Current Drive ◽  
Lower Hybrid ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Linear Diffusion ◽  
Neighbouring Region ◽  
Nonlinear Relation ◽  
Single Path ◽  
Component Parallel

This paper outlines a theory of absorption of lower-hybrid (LH) waves in an electron plasma that is based on the nonlinear relation between grad │E3│2, where E3 is the electric field component parallel to the external homogeneous magnetic field, and the space dependent quasi-linear diffusion coefficient, and consequently between grad │E3│2 and the absorption. A local absorption induces an increase of the value of the gradient in the neighbouring region and thereby extends the absorption domain. In this way virtually total ‘single-path’ absorption of the injected LH power is obtained. The theory also allows an explanation of the density limit in current drive.

Observation of Parametric Decay of a Pumping Wave in Lower Hybrid Wave Heating and Current Drive Experiments at the FT-2 Tokamak

2019 ◽  
Vol 45 (12) ◽  
pp. 1134-1141 ◽  
Author(s):  
V. V. D’yachenko ◽  
A. N. Konovalov ◽  
A. Yu. Stepanov ◽  
A. B. Altukhov ◽  
E. Z. Gusakov ◽  
...  
Keyword(s):  
Current Drive ◽  
Lower Hybrid ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Parametric Decay ◽  
Wave Heating

Optimization of OH coil recharging scenario of quasi-steady operation in tokamak fusion reactor by lower hybrid wave current drive

1984 ◽  
Vol 1 (3) ◽  
pp. 265-277 ◽  
Author(s):  
Masayoshi Sugihara ◽  
Noboru Fujisawa ◽  
Takumi Yamamoto ◽  
Satoshi Nishio ◽  
Takashi Okazaki ◽  
...  
Keyword(s):  
Fusion Reactor ◽  
Current Drive ◽  
Lower Hybrid ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Tokamak Fusion Reactor

scholarly journals Large Current Drive Experiments Using Simplified Multijunction Lower Hybrid Wave Launcher in JT-60U.

1995 ◽  
Vol 37 (2) ◽  
pp. 124-132 ◽  
Author(s):  
Takashi KONDOH ◽  
Yoshitaka IKEDA ◽  
Kenkichi USHIGUSA ◽  
Masami SEKI ◽  
Shunsuke IDE ◽  
...  
Keyword(s):  
Current Drive ◽  
Lower Hybrid ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Large Current

Effect of Changes in Plasma Profiles on Current Drive by Lower Hybrid Wave in Tokamak

1984 ◽  
Vol 53 (2) ◽  
pp. 472-475
Author(s):  
Mitsuru Yamagiwa ◽  
Toshinori Michishita ◽  
Hiroshi Nishihara
Keyword(s):  
Current Drive ◽  
Lower Hybrid ◽  
Hybrid Wave ◽  
Lower Hybrid Wave

Thermal and Thermo-Mechanical Analysis of Lower Hybrid Wave Antenna in East Tokamak

2010 ◽  
Author(s):  
Jun Li ◽  
Fukun Liu
Keyword(s):  
Thermal Stresses ◽  
Plasma Heating ◽  
Thermal Flux ◽  
High Energy ◽  
Current Drive ◽  
Lower Hybrid ◽  
Thermal Loads ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Wave Antenna

Today, the tokamak has emerged as the leading approach to controlling nuclear fusion for the purpose of electrical power generation. As an important power system in experimental advanced superconducting tokamak (EAST), an advanced steady-state plasma physics experimental device, the lower hybrid current drive (LHCD) system provides a high-energy microwave for plasma heating and current drive. The microwave power is delivered to the plasma through the lower hybrid wave (LHW) antenna. In order to couple microwave energy to the plasma more efficiently, the antenna is exposed to the plasma. During the plasma operation, the LHW antenna will not only withstand the high thermal flux from the plasma but also the thermal stress owing to thermal loads. The temperature of the antenna has been analyzed using the numerical analysis method. At the same time, the thermal stresses and displacements due to thermal loads are also calculated using the finite element code. The paper is organized as follows: First, the structure of the LHW antenna is briefly described; the 3D model is given. Secondly, thermal loads and boundary conditions are shown and discussed. Finally, the temperature, thermal stresses and displacements are simulated. All the results of the simulation are presented and discussed. These could be useful for the development of the lower hybrid wave antenna.

Heat transport analysis of the improved confinement discharge with LHW in the HT-7 tokamak

2009 ◽  
Vol 76 (2) ◽  
pp. 229-237 ◽  
Author(s):  
X. M. ZHANG ◽  
X. SHEN ◽  
B. N. WAN ◽  
Z. W. WU ◽  
J. FU ◽  
...  
Keyword(s):  
Heat Transport ◽  
Current Drive ◽  
Lower Hybrid ◽  
Ion Temperature ◽  
Hybrid Wave ◽  
Lower Hybrid Wave ◽  
Transport Barriers ◽  
Internal Transport Barriers ◽  
Transport Analysis ◽  
Internal Transport

AbstractIn the HT-7 tokamak, heat transport analysis is carried out for the lower hybrid current drive (LHCD) experiments. Electrons and ions are coupled and good confinement can be obtained by properly optimizating LHCD and plasma parameters. Under the conditions that the plasma current is about 220 kA, the lower hybrid wave (LHW) power is about 300 kW and the central line-averaged density is about 1.5×1013 cm−3, lower hybrid wave power deposition is off-axis. Local transport analysis illustrated that both electron and ion thermal diffusivities are decreased during the LHW phase, and the electron internal transport barriers (eITBs) are formed while been accompanied by the ion internal transport barriers (iITBs) during LHW phase. Ions are heated by electron-ion collision in the region of the barriers although the ohmic power and the LHW power were absorbed by the electrons. Both electron temperature and ion temperature are increased during the LHW phase, and in the confinement region, the electron-to-ion temperature ratio, Te/Ti varies from 2.0 ~ 2.5 during OH phase to 1.3 ~ 1.6 during LHW injected into the plasma, which shows that electron confinement is not degraded by the electron–ion collisions meanwhile ions are also confined. The energy confinement is increased from 13 ms to 25 ms due to the formation of electron and ion internal transport barries after the LHW is injected into the plasma. LHW driven current and bootstrap current contribute to 60% of the total current.

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