Recent works [1,2], including the effect of spectral broadening due to wave physics of the plasma edge, show that non inductive current is efficiently driven in internal transport barrier (ITB) plasmas in JET [1-3], at about two thirds of the minor radius, by lower hybrid current drive (LHCD). Modelling of q and magnetic shear profiles has been used to design ITER-relevant ITB discharges for JET at high βN (≈2.5). This shows that low/negative shear (s≈-0.1) at normalized radii ρ ≈ 0.71 and ρ ≈ 0.75 would be sustained for two seconds by operating with launched n//Peak =2.3. Results of LHCD modelling relevant to the ITB scenario of ITER [4] are discussed. The current (efficiency, η≈ 0.2x1020 MA m -2 MW-1) is mostly driven at: i) at r/a ≈ 0.80 by considering moderate LH spectral broadening effects at the edge, ii) at r/a ≈0.75 with weaker effects, as would be expected in the case of lower operating electron temperatures in the scrape-off layer (SOL). ITB experiments of FTU at high magnetic field (8T) by means of LHCD performed during the current ramp-up are also considered. Predictive modelling of combined LHCD and electron cyclotron heating (ECH) in extraordinary (X)-mode has been performed to try to find ways to extend the ITB parameter-space.
Modelling of experiments with ITER-relevant q-profile control at high βN by means of the lower hybrid current drive / Castaldo, C.; Cesario, R.; Cardinali, A.; Marinucci, M.; Micozzi, Paolo; Panaccione, L.; Anania, M.; Di Flauro, S.; Eusepi, B.; Pajewski, L.; Schettini, G.; Giruzzi, G.. - STAMPA. - 1:(2006), pp. 528-531. (Intervento presentato al convegno 33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006 tenutosi a Roma nel 19-23 giugno 2006).
Modelling of experiments with ITER-relevant q-profile control at high βN by means of the lower hybrid current drive
Cardinali A.;MICOZZI, Paolo;Pajewski L.;Schettini G.;
2006
Abstract
Recent works [1,2], including the effect of spectral broadening due to wave physics of the plasma edge, show that non inductive current is efficiently driven in internal transport barrier (ITB) plasmas in JET [1-3], at about two thirds of the minor radius, by lower hybrid current drive (LHCD). Modelling of q and magnetic shear profiles has been used to design ITER-relevant ITB discharges for JET at high βN (≈2.5). This shows that low/negative shear (s≈-0.1) at normalized radii ρ ≈ 0.71 and ρ ≈ 0.75 would be sustained for two seconds by operating with launched n//Peak =2.3. Results of LHCD modelling relevant to the ITB scenario of ITER [4] are discussed. The current (efficiency, η≈ 0.2x1020 MA m -2 MW-1) is mostly driven at: i) at r/a ≈ 0.80 by considering moderate LH spectral broadening effects at the edge, ii) at r/a ≈0.75 with weaker effects, as would be expected in the case of lower operating electron temperatures in the scrape-off layer (SOL). ITB experiments of FTU at high magnetic field (8T) by means of LHCD performed during the current ramp-up are also considered. Predictive modelling of combined LHCD and electron cyclotron heating (ECH) in extraordinary (X)-mode has been performed to try to find ways to extend the ITB parameter-space.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
