%A"Dutch, M J" %A"Hofmann, F" %A"Duval, B P" %A"Hirt, A" %A"Joye, B" %A"Lister, J B" %A"Martin, Y" %A"Nieswald, C" %A"Pochelon, A" %A"Weisen, H [Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP)]" %D1994 %I; Ecole Polytechnique Federale, Lausanne (Switzerland). Centre de Recherche en Physique des Plasma (CRPP) %2 %J[] %K70 PLASMA PHYSICS AND FUSION TECHNOLOGY, DIVERTORS, CONFIGURATION, EDGE LOCALIZED MODES, CONTROL, TCV TOKAMAK, H-MODE PLASMA CONFINEMENT, EXPERIMENTAL DATA, JOULE HEATING, MAGNETIC SURFACES, PLASMA DENSITY, 700340, PLASMA WAVES, OSCILLATIONS, AND INSTABILITIES %PMedium: X; Size: 11 p. %TELM control during double-null Ohmic H-modes in TCV %XPrecise control of the shape and position of Double-Null divertor configurations in the TCV tokamak has been used to reliably trigger the transition from ELM-free to ELMy Ohmic H-Mode and back. Pre-programmed modulation of the magnetic axis height, with fixed shaping field, caused the plasma to evolve, during a single discharge, between Double-Null-Upper, Double-Null and Double-Null-Lower configurations, with both X-points remaining close to the last closed flux surface. The transition from ELM-free to ELMy and back again was observed to be synchronous with the configuration modifications. Using this method, several ELM-free and ELMy phases enabled reproducible disruption-free H-mode discharges in TCV lasting up to 1.5 seconds. The plasma density during a long-duration H-mode was directly controlled by feeding back onto the vertical height of the magnetic axis. (author) 4 figs., 18 refs. %0Technical Report %NLRP-501/94;Other: ON: DE95611651; TRN: CH9400373009171 %1 %CSwitzerland %Rhttps://doi.org/ Other: ON: DE95611651; TRN: CH9400373009171 CHN %GEnglish