Design and implementation of power and phase feedback control system for ICRH on EAST

Zhao, Chen; Zhao, Yanping; Chen, Gen; Cheng, Yan; Wang, Jianhua; Zhang, Jiahui; Yang, Yu

doi:10.1007/s41365-018-0362-8

Cited by 9 publications

(5 citation statements)

References 12 publications

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“…On the one hand the absence of real time feedback control of EAST ICRH port phasing [25] can be responsible for this, but on the other hand, Mo content varied in agreement with what is expected from observations in other devices, namely an increase in Mo production going from dipole to monopole. Once again, this peculiar observation leads us to consider the high field side wall as a likely source of Mo correlated with the I-port antenna settings.…”

Section: Far-field Effects On Inner Wallsupporting

confidence: 78%

“…Most metallic impurities were moreover insensitive to ICRH phasing that was not feedback controlled [25], which is not consistent with similar experiments and modeling predictions [1,11,47] as shown in appendix 2. Only Mo reacted to phase changes with increasing interactions over phase scan from dipole to monopole.…”

Section: Discussion and Prospectsmentioning

confidence: 61%

“…The power lost in the transmission line is not measured experimentally, however calculation of the RF losses show that they are always less than 15%, resulting from uncertainties on power estimations detailed in [24]. In addition, the phase between straps cannot be changed in real time [25]. The different phase and matching are therefore set in the vacuum and the same settings are maintained with the plasma.…”

Section: Experimental Conditions and Protocol In Eastmentioning

confidence: 99%

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Metallic impurity content behavior during ICRH-heated L-mode discharges in EAST

Urbanczyk¹,

Zhang²,

Zhang³

et al. 2020

Nucl. Fusion

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HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de

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Section: Far-field Effects On Inner Wallsupporting

confidence: 78%

Section: Discussion and Prospectsmentioning

confidence: 61%

Section: Experimental Conditions and Protocol In Eastmentioning

confidence: 99%

See 1 more Smart Citation

Metallic impurity content behavior during ICRH-heated L-mode discharges in EAST

Urbanczyk¹,

Zhang²,

Zhang³

et al. 2020

Nucl. Fusion

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show abstract

“…Finally, perfect electric conductor conditions are enforced on all the boundaries, except the four coaxial ports of characteristic impedance Z 0 = 50Ω, each lumped excited by 1 A in dipole phasing. Note reality may be different from exact dipole phasing case as phases on straps were not feedback controlled [34]. The absence of a Faraday Screen in the imported CAD model could furthermore lead to slight overestimations of the coupling, but this simplification allows significant mesh reduction and therefore reduces the time of resolution and memory consumption which was already at the limit of our workstation.…”

Section: Coupling Simulations With Raplicasolmentioning

confidence: 99%

Optimization of discharges with ion cyclotron range of frequencies using local gas injection in EAST

et al. 2019

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In view of improving Ion Cyclotron Range of Frequencies (ICRF) wave coupling in EAST (Experimental Advanced Superconducting Tokamak) necessary to obtain high-power discharges, two series of experiments in L-mode were devoted to the use of local gas injection as a tool to increase density in front of the antennas.During the first session, the quantity of deuterium simultaneously puffed from five different poloidal positions on each side of one ICRF antenna was gradually increased. Steady gas puffing on this antenna (~8.10 20 e/s) increased antenna coupling resistance by 100%, but puffing more gas did not provoke any further improvement.Plasma central electron density was not kept constant when using local puff but kept increasing during the discharges. During the second session, the global density was well-controlled and remained constant, the distance between the separatrix and the first wall was increased by 2cm allowing, the gas to spread better, and puffing more gas this time lead to better wave coupling. The same amount of gas was then puffed from three different locations and changes in SOL (Scrape-Off Layer) parameters were measured from several locations. Extensive analysis of the edge diagnostics made it possible to observe an electron density increase and a temperature decrease caused by the ionization of neutrals in the SOL. Heat loads on the divertor targets were slightly mitigated by gas injection, which is favorable from the perspective of long pulse scenario development. Injection at mid-plane led to the best results with the highest coupling simultaneously achieved for both antennas and smallest heat loads on the divertor target (below 1MW/m²). As far as wave coupling efficiency is concerned, most experimental trends were also successfully reproduced by antenna modelling with the RAPLICASOL finite element code with experimental density profiles from reflectometry as the main input.

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“…Ion cyclotron wave resonance heating system (ICRH) which is one of the most important auxiliary system in EAST provides conditions for heating the plasma [1]. ICRH consists of a phaseshiftable radiofrequency (RF) signal source, eight 1.5 MW high-power transmitters, eleven coaxial switches, transmission lines, matching networks, decoupling branches, and antennas [2][3][4]. In the original coaxial control system, a single-chip microcomputer is used as the control chip and several relays are responsible for determining the position information of the coaxial switch.…”

Section: Introductionmentioning

confidence: 99%

Design and control of coaxial switching system for ion cyclotron wave resonance heating system of EAST

Cheng

Guang

Chen

et al. 2020

Plasma Sci. Technol.

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Ion cyclotron wave resonance heating system (ICRH) which is one of the most important auxiliary system in EAST provides conditions for heating the plasma. In order to make the whole transmission network of ICRH form the required state, the coaxial switching system was developed, which mainly consists of 11 same coaxial switches. Each coaxial switch has a controller with an RS485 communication interface and is able to switch between two states. All controllers are integrated to an RS485 hub which connects to the computer. A master computer software is developed to control the coaxial switching system so as to achieve the state needs of ICRH. Moreover, several rounds of experiments show that the coaxial switching system operates reliably. The coaxial switching system has already been applied to normal use currently.

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Design and implementation of power and phase feedback control system for ICRH on EAST

Cited by 9 publications

References 12 publications

Metallic impurity content behavior during ICRH-heated L-mode discharges in EAST

Metallic impurity content behavior during ICRH-heated L-mode discharges in EAST

Optimization of discharges with ion cyclotron range of frequencies using local gas injection in EAST

Design and control of coaxial switching system for ion cyclotron wave resonance heating system of EAST

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