As widely documented by available experimental and modelling data [1,2], a broadening in the lower hybrid (LH) wave frequency and n∥ (parallel wavenumber) spectrum is produced by parametric instability (PI) that can affect the propagation and deposition of the LH power launched in tokamak plasmas. The electronic dynamics at the plasma edge mainly determines the occurrence of the ion-sound quasimode-driven PI, whose growth rate is intrinsically high at the radial layers close to the antenna-plasma interface, as its maximum occurs in the same conditions necessary for performing the antenna coupling (i.e.: ωpe/ω0 ≳1 at the plasma edge). The radial extent in the plasma of the region with high growth rate determines the spectral broadening size. Radially deeper is this region, smaller are the convective losses and consequently bigger is the spectral broadening. The present work shows that considering a case of relatively high densities (ne) and low electron temperatures (Te) of the scrape-off layer (SOL), the LH spectral broadening should be strong enough to produce the radiofrequency (RF) power deposition at the very plasma periphery of ITER (International Thermonuclear Experiment Reactor). Conversely, operating with slightly low ne and high Te in the SOL, the radial extent of the PI region results reduced and, consequently, a useful LHCD can be performed in the plasma bulk.
|Publication status||Published - 2008|
|Event||35th European Physical Society Conference on Plasma Physics, EPS 2008 Combined with the 10th International Workshop on Fast Ignition of Fusion Targets - , Greece|
Duration: 1 Jan 2008 → …
|Conference||35th European Physical Society Conference on Plasma Physics, EPS 2008 Combined with the 10th International Workshop on Fast Ignition of Fusion Targets|
|Period||1/1/08 → …|
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
Cesario, R., Anania, M. P., Cardinali, A., Castaldo, C., De Arcangelis, D., Di Flauro, S., ... Tuccillo, A. A. (2008). Lower hybrid current drive at high densities of ITER. Paper presented at 35th European Physical Society Conference on Plasma Physics, EPS 2008 Combined with the 10th International Workshop on Fast Ignition of Fusion Targets, Greece.