000265558 001__ 265558
000265558 005__ 20190507151358.0
000265558 0247_ $$2doi$$a10.1088/1741-4326/ab1e1e
000265558 037__ $$aARTICLE
000265558 245__ $$aControl of NTMs and integrated multi-actuator plasma control on TCV
000265558 260__ $$c2019-04-30
000265558 269__ $$a2019-04-30
000265558 336__ $$aJournal Articles
000265558 500__ $$aAccepted Manuscript online 30 April 2019
000265558 520__ $$aThe control of 2/1 neoclassical tearing modes (NTMs) with electron cyclotron (EC) waves has been studied both experimentally and numerically on TCV. Dynamic evolutions of NTMs along with time-varying deposition locations of the control beam have been studied in detail. The prevention of NTMs by means of preemptive EC (i.e. the control beam is switched on before the mode onset) has also been explored. A small sinusoidal sweeping with full amplitude of 0.07 (normalized to the minor radius) has been added to the control beam in two of the experiments to facilitate the comparison between NTM stabilization and prevention. It is shown that the prevention of NTMs is more efficient than NTM stabilization in terms of the minimum EC power required. Interpretative simulations with the Modified Rutherford Equation (MRE) have been performed to better quantify various effects, with coefficients well defined by dedicated experiments. Specifically, in order to obtain more insight on the dominant dependencies, a simple ad-hoc analytical model has been proposed to evaluate the time-varying classical stability index Δ' in the test discharges, based on the Δ'-triggered nature of these 2/1 NTMs. This allows simulating well the entire island width evolution with the MRE, starting from zero width and including both NTM stabilization and prevention cases for the first time. The exploration of NTM physics and control has facilitated the development of an NTM controller that is independent of the particular features of TCV and has been included in a generic plasma control system (PCS) framework. Integrated control of 2/1 NTMs, plasma β (the ratio of plasma pressure to magnetic pressure) and model-estimated safety factor q profiles has been demonstrated on TCV.
000265558 6531_ $$aNTM stabilization and prevention
000265558 6531_ $$aModified Rutherford Equation (MRE)
000265558 6531_ $$aintegrated control
000265558 700__ $$g263675$$aKong, Mengdi$$0254299
000265558 700__ $$aBlanken, Thomas
000265558 700__ $$g177133$$aFelici, Federico$$0242258
000265558 700__ $$g252607$$aGalperti, Cristian$$0248644
000265558 700__ $$aMaljaars, Bert
000265558 700__ $$g106355$$aSauter, Olivier$$0240094
000265558 700__ $$g281093$$aVu, Ngoc Minh Trang$$0254541
000265558 700__ $$g270892$$aCarpanese, Francesco$$0254212
000265558 700__ $$g230836$$aMerle, Antoine$$0247013
000265558 700__ $$g105910$$aMoret, Jean-Marc$$0240130
000265558 700__ $$g276927$$aPesamosca, Federico$$0253944
000265558 700__ $$aPoli, Emanuele
000265558 700__ $$aReich, Matthias
000265558 700__ $$g241636$$aTeplukhina, Anna$$0247983
000265558 710__ $$aThe TCV team
000265558 710__ $$aThe EUROfusion MST1 team
000265558 773__ $$tNuclear Fusion
000265558 8564_ $$uhttps://infoscience.epfl.ch/record/265558/files/Control_of_NTMs_clean.pdf$$zFinal$$s1629141
000265558 8560_ $$falessandra.bianchi@epfl.ch
000265558 909C0 $$zPasquier, Simon$$xU10136$$xU12267$$xU12269$$xU12271$$xU10559$$xU12273$$xU10557$$xU12270$$xU10137$$xU10636$$xU12266$$xU10635$$xU10558$$xU12268$$xU12272$$pSPC$$mstefano.coda@epfl.ch$$0252028
000265558 909CO $$ooai:infoscience.epfl.ch:265558$$particle$$pSB
000265558 960__ $$amengdi.kong@epfl.ch
000265558 961__ $$aalessandra.bianchi@epfl.ch
000265558 973__ $$aEPFL$$sACCEPTED$$rREVIEWED
000265558 980__ $$aARTICLE
000265558 981__ $$aoverwrite