Data di Pubblicazione:
2001
Abstract:
Steady state electron heat transport of FTU high density plasmas (iin« 0.45-1 1020
m~3) during Electron Cyclotron Resonance Heating (ECRH) are compared to predictions of a model
based on the assumption of a threshold gradient length, Lfc, in the electron temperature Te beyond
which electron thermal conductivity, %e, switches from low to high values. The model accounts for the
stiffness of Te slope observed in FTU plasmas heated with quite different radial shapes of the ECRH
power deposition profile. These profiles are achieved by toroidal field tuning and steering two gaussian
beams delivering up to 850 kW to the plasma in a radial position, p, ranging from p ~ 0.25 to p « 0.5.
Plasma response is modelled by assuming the electron conductivity as %e = XeO + a Te^^2 (l/Lj -
l/Lfc)^2') nere Te^ reflects the gyro-Bohm assumption, %EURQ represents the heat transport for Lf>Ljc
while a, the so-called stiffness coefficient, is adjusted to cope with the observed experimental data. The
term (1/L? - l/L^)1^ which sets in for LT the same stiffness coefficient, a, and the same 'low' conductiviy XeO.
Tipologia CRIS:
04.01 Contributo in Atti di convegno
Keywords:
tokamak; diffusione termica; radiofrequenza
Elenco autori:
Sozzi, Carlo; Cirant, SANTE GIOVANNI; Granucci, Gustavo; Jacchia, Alessandro; Bruschi, Alessandro
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