Particle balance study for the fueling efficiency in KSTAR experiments 2013

Juhn, June-Woo; Hahn, S.H.; Hong, Suk–Ho; Song, J. H.; Kim, Y. O.; Kim, K. P.; Kim, J. S.

doi:10.3938/jkps.65.1304

Cited by 4 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A decrease in fueling efficiency with the increase in averaged plasma density before the injection was observed on Tore Supra, 4 HL-2A, 6 KSTAR. 1 A slight rise of the fueling efficiency with the increase in the molecular beam density was demonstrated on Tore Supra. 4 The absence of precise measurements of the molecular beam parameters at the entry of the plasma, low ability to vary injection parameters, and scattering of measured fueling efficiency from shot to shot complicate obtaining a comprehensive picture and quantitative description of how the efficiency of SMBI depends on various injection scenarios.…”

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 97%

“…The traditional fueling method used on fusion machines is by gas puffing (GP), which results in edge fueling and demonstrates its highest efficiency, defined as the ratio of the maximum increment of plasma density to the injected inventory, in divertor configurations with less than 20%. 1,2 Supersonic molecular beam injection (SMBI) 3 is similar to GP apart from using a Laval nozzle for acceleration of molecules to supersonic speeds. SMBI has been widely used on different machines 1,[4][5][6][7][8][9][10][11] and demonstrated fueling efficiencies in the range of 20%-60%.…”

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 99%

“…1,2 Supersonic molecular beam injection (SMBI) 3 is similar to GP apart from using a Laval nozzle for acceleration of molecules to supersonic speeds. SMBI has been widely used on different machines 1,[4][5][6][7][8][9][10][11] and demonstrated fueling efficiencies in the range of 20%-60%. SMBI is a useful tool to perform fast plasma density control especially in H-mode where GP becomes increasingly ineffective.…”

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 99%

“…In addition, SMBI is characterized by lower wall retention compared to GP, essential for long pulse tokamak operations. 1,8 On EAST and KSTAR, SMBI is implemented in the feedback density control system.…”

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 99%

See 3 more Smart Citations

Influence of injection parameters on fueling efficiency of supersonic molecular beam injection into turbulent fusion plasmas

Avdeeva¹,

Naulin²,

Nielsen³

et al. 2020

Physics of Plasmas

View full text Add to dashboard Cite

The fueling efficiency of supersonic molecular beam injection (SMBI) depends on injection parameters. In this article, we report on simulations of SMBI into turbulent edge fusion plasmas. Density continuity equations, which describe the dynamics of molecules and Franck-Condon atoms, are coupled with the plasma equations in the hot-edge-sol-electrostatic (HESEL) drift-fluid model. Numerical simulations, with parameters relevant to experimental conditions, are performed in order to investigate the dependency of the fueling efficiency of SMBI on the molecular beam density, velocity, and beam width. In all conditions, the efficiency grows with the increase in the molecular beam velocity. The variation in efficiency with respect to the beam density depends on the plasma pressure and the ratio of the density source, produced by ionization of neutrals, to the plasma density source provided by core fueling. The effect of the molecular beam width is pronounced only if the beam density is high and the plasma, into which the beam is injected, is relatively dense and hot. The influence of plasma fluctuations on SMBI is weak; however, a strong neutral injection leads to suppression of a turbulence transport due to relaxation of pressure gradient profiles.

show abstract

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 97%

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 99%

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 99%

Section: Influence Of Injection Parameters On Fueling Efficiency Of Supersonic Molecular Beam Injection Into Turbulent Fusion Plasmas I Imentioning

confidence: 99%

See 2 more Smart Citations

Influence of injection parameters on fueling efficiency of supersonic molecular beam injection into turbulent fusion plasmas

Avdeeva¹,

Naulin²,

Nielsen³

et al. 2020

Physics of Plasmas

View full text Add to dashboard Cite

show abstract

“…Density feedback implementation was done since the first year [3] based on the line-averaged electron density diagnostics [16], but has not been utilized very often because of (1) uncertainties on the measurement in the plasmas with large ELM crashes, and (2) low fuelling efficiency of the outboard gas [17]. Several minor improvements on the density measurement was done, and research seeking for better efficiency introduced additional PID by Supersonic Molecular Beam Injections (SMBI) [18].…”

Section: Progress On Kinetic Controlsmentioning

confidence: 99%

Progress and plan of KSTAR plasma control system upgrade

Hahn

Kim

Penaflor

et al. 2016

Fusion Engineering and Design

View full text Add to dashboard Cite

h i g h l i g h t s• Recent achievements of the KSTAR plasma control system are described.• Requirements and results of the testbed system for the future upgrade of the KSTAR plasma control system are presented.• An overview of the upgrade layout based is given. a b s t r a c t The plasma control system (PCS) has been one of essential systems in annual KSTAR plasma campaigns: starting from a single-process version in 2008, extensive upgrades are done through the previous 7 years in order to achieve major goals of KSTAR performance enhancement. Major implementations are explained in this paper. In consequences of successive upgrades, the present KSTAR PCS is able to achieve ∼48 s of 500 kA plasma pulses with full real-time shaping controls and real-time NB power controls. It has become a huge system capable of dealing with 8 separate categories of algorithms, 26 actuators directly controllable during the shot, and real-time data communication units consisting of +180 analog channels and +600 digital input/outputs through the reflective memory (RFM) network. The next upgrade of the KSTAR PCS is planned in 2015 before the campaign. An overview of the upgrade layout will be given for this paper. The real-time system box is planned to use the CERN MRG-Realtime OS, an ITER-compatible standard operating system. New hardware is developed for faster real-time streaming system for future installations of actuators/diagnostics.

show abstract