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Title: Assessment of the LH wave for demo in pulsed and steady state scenario

The Lower Hybrid Current Drive (LHCD) has been analysed in DEMO tokamak plasma in the 'pulsed and steady state regime' considering two plasma scenarios characterized, respectively, by flat density profile and peaked density profiles. We have obtained LH deposition profiles in cases of neglecting the effect of spectral broadening produced by PI at the edge. By comparing the Power Deposition Profiles for both DEMO scenarios ('flat' and 'peaked'), the SOL of DEMO does not play any role in the absorption of the LH wave. In all cases the deposition is localized inside the separatrix layer r/a≤1. By lowering the parallel wave-number peak of the power spectrum from 1.8 to 1.5, the accessibility condition in both case prevents the power from reaching the deposition layer apart from a small fraction which pertains to the higher n∥ of the power spectrum. The spectrum centred at 1.8 is suggested to be useful in DEMO. More realistically, as supported by available data of LHCD in a wide range of operating densities, the effect of parametric decay instability (PDI) can produce a spectral broadening which should be included in the simulations. Further studies would be necessary for assessing the temperature profiles in the SOL atmore » reactor-graded conditions. This is because, if the SOL temperature is at least of the order of 50 to 100 eV, the effect of PDI broads the spectrum up to n∥≤10, and the deposition profile is slightly wider but not much shifted outwards.« less
Authors:
; ; ; ; ; ;  [1] ;  [2] ; ;  [3] ; ;  [4]
  1. Associazione Euratom-ENEA sulla Fusione, C.R. Frascati, Via Enrico Fermi, 45 00044, Frascati, Roma (Italy)
  2. Associazione Euratom-ENEA sulla Fusione, C.R. Frascati, Via Enrico Fermi, 45 00044, Frascati, Roma, Italy and Department of Engineering, Roma Tre University, Via Vito Volterra, 62, 00146, Roma (Italy)
  3. Consorzio CREATE, Universita degli Studi di Napoli Federico II, Via Claudio 21, 80125, Napoli (Italy)
  4. Department of Engineering, Roma Tre University, Via Vito Volterra, 62, 00146, Roma (Italy)
Publication Date:
OSTI Identifier:
22263889
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1580; Journal Issue: 1; Conference: 20. topical conference on radiofrequency power in plasmas, Sorrento (Italy), 25-28 Jun 2013; Other Information: (c) 2014 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; DECAY INSTABILITY; DENSITY; DEPOSITION; LINE BROADENING; LOWER HYBRID CURRENT DRIVE; PEAKS; PLASMA; PULSES; SIMULATION; SPECTRA; TOKAMAK DEVICES