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  are discussed. The current (efficiency, η≈ 0.2x1020MA m-2MW-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.
|Publication status||Published - 2006|
|Event||33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006 - , Italy|
Duration: 1 Jan 2006 → …
|Conference||33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006|
|Period||1/1/06 → …|
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
Castaldo, C., Cesario, R., Cardinali, A., Marinucci, M., Micozzi, P., Panaccione, L., ... Giruzzi, G. (2006). Modelling of experiments with ITER-relevant q-profile control at high β. Paper presented at 33rd European Physical Society Conference on Plasma Physics 2006, EPS 2006, Italy.