Progress of LHCD and IBW Heating Experiments on HT-7 Tokamak

Gao, Xiang; Zhao, Yanping; Gong, Xianzu; Hu, Liqun; Shan, Jiafang; Toi, K.; Morita, S.; Jin, Lei; Xu, Ping; Xu, Qianfan; Liu, Haiqing; Yang, Jian; Wan, Baonian; Li, Jiangang; Team, Ht

doi:10.1088/1009-0630/11/4/02

Cited by 3 publications

(2 citation statements)

References 19 publications

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“…Lower hybrid (LH) waves have been used for many years on numerous tokamaks (C-MOD [1], EAST [2], HT-7 [3], JET [4], Tore Supra [5] and TRIAM-1 M [6]) to drive a toroidal current in the plasma. In superconducting machines (Tore Supra, TRIAM-1 M, EAST, HT-7), long pulse operation has been successfully demonstrated using lower hybrid current drive (LHCD), drawing benefit both from the high current drive (CD) efficiencies, well above those of other auxiliary heating systems, and the ability to drive an off axis current.…”

Section: Introductionmentioning

confidence: 99%

Advances in multi-megawatt lower hybrid technology in support of steady-state tokamak operation

et al. 2014

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It has been demonstrated that lower hybrid current drive (LHCD) systems play a crucial role for steady-state tokamak operation, owing to their high current drive (CD) efficiency and hence their capability to reduce flux consumption. This paper describes the extensive technology programmes developed for the Tore Supra (France) and the KSTAR (Korea) tokamaks in order to bring continuous wave (CW) LHCD systems into operation. The Tore Supra LHCD generator at 3.7 GHz is fully CW compatible, with RF power PRF = 9.2 MW available at the generator to feed two actively water-cooled launchers. On Tore Supra, the most recent and novel passive active multijunction (PAM) launcher has sustained 2.7 MW (corresponding to its design value of 25 MW m−2 at the launcher mouth) for a 78 s flat-top discharge, with low reflected power even at large plasma-launcher gaps. The fully active multijunction (FAM) launcher has reached 3.8 MW of coupled power (24 MW m−2 at the launcher mouth) with the new TH2103C klystrons. By combining both the PAM and FAM launchers, 950 MJ of energy, using 5.2 MW of LHCD and 1 MW of ICRH (ion cyclotron resonance heating), was injected for 160 s in 2011. The 3.7 GHz CW LHCD system will be a key element within the W (for tungsten) environment in steady-state Tokamak (WEST) project, where the aim is to test ITER technologies for high heat flux components in relevant heat flux density and particle fluence conditions. On KSTAR, a 2 MW LHCD system operating at 5 GHz is under development. Recently the 5 GHz prototype klystron has reached 500 kW/600 s on a matched load, and studies are ongoing to design a PAM launcher. In addition to the studies of technology, a combination of ray-tracing and Fokker–Planck calculations have been performed to evaluate the driven current and the power deposition due to LH waves, and to optimize the N∥ spectrum for the future launcher design. Furthermore, an LHCD system at 5 GHz is being considered for a future upgrade of the ITER Heating and Current Drive systems, with a power capability of 20 MW coupled to the plasma using a PAM launcher. An R&D programme is being conducted at CEA/IRFM to develop a BeO vacuum window which is a safety critical component of the transmission line. In addition, a mock-up of a TE10–TE30 mode converter at 5 GHz, designed for a rectangular transmission line, has been manufactured and successfully tested on Tore Supra at low RF power.

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Section: Introductionmentioning

confidence: 99%

Advances in multi-megawatt lower hybrid technology in support of steady-state tokamak operation

et al. 2014

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“…The high current drive efficiency of Lower Hybrid waves makes Lower Hybrid Current Drive system a crucial actuator to save inductive flux and to generate additional plasma current in present day tokamak experiments. Several superconducting tokamaks (EAST [1], HT-7 [2], Tore Supra [3], TRIAM-1M [4]) have demonstrated the feasibility of long pulse operation using Lower Hybrid Current Drive (LHCD). Continuous Wave (CW) LHCD capabilities are planned in the KSTAR [5] [6] and the SST1 [7] tokamaks.…”

Section: Introductionmentioning

confidence: 99%

Recent progress on lower hybrid current drive and implications for ITER

Hillairet¹,

Goniche²,

Bae³

et al. 2013

Nucl. Fusion

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The sustainment of steady-state plasmas in tokamaks requires efficient current drive systems. Lower Hybrid Current Drive (LHCD) is currently the most efficient method to generate a continuous additional off-axis toroidal plasma current as well as reduce the poloidal flux consumption during the plasma current ramp-up phase. The operation of the Tore Supra ITER-like LH launcher has demonstrated the capability to couple LH power at ITER-like power densities with very low reflected power during long pulses. In addition, the installation of eight 700kW/CW klystrons at the LH transmitter has allowed increasing the total LH power in long pulse scenarios. However, in order to achieve pure stationary LH sustained plasmas, some R&D are needed to increase the reliability of all the systems and codes, from the RF sources to the plasma scenario prediction. The CEA/IRFM is addressing some of these issues by leading a R&D program towards an ITER LH system and by the validation of an integrated LH modeling suite of codes. In 2011, the RF design of a mode converter has been validated at low power. A 500 kW/5 s RF window is currently under manufacturing and will be tested at high power in 2012 in collaboration with NFRI. All of this work aims to reduce the operational risks associated with the ITER steady-state operations.

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The Design of High Voltage DC Power Supply of 4.6GHZ/500MW LHCD

Huang

2011

AMM

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The steady-state and transient performances of the power supply system of LHCD (Lower Hybrid Current Drive) heating system are highly demanded which makes it difficult to design the power source. In this thesis, the method of designing the 4.6GHZ/6MW power source of LHCD of EAST is discussed. And the results of the experiment are provided and some special characteristics are analysed to prove the accuracy of the method.

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Progress of LHCD and IBW Heating Experiments on HT-7 Tokamak

Cited by 3 publications

References 19 publications

Advances in multi-megawatt lower hybrid technology in support of steady-state tokamak operation

Advances in multi-megawatt lower hybrid technology in support of steady-state tokamak operation

Recent progress on lower hybrid current drive and implications for ITER

The Design of High Voltage DC Power Supply of 4.6GHZ/500MW LHCD

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