regression Isotope Dependence of Confinement in JET Deuterium and Hydrogen Plasmas Type I ELMy Hmode in hydrogen and deuterium Impossibility of establishing the same density ID: 921233
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Slide1
Fig.1 Log thermal
energy
regression
Isotope Dependence of Confinement in JET Deuterium and Hydrogen
Plasmas
Type I
ELMy H-mode in hydrogen and deuterium:Impossibility of establishing the same density for the same particle source (gas puffing): particle confinement lower in hydrogen.Strong, similar, isotope dependence of global confinement on ion mass A in all transport channels (energy, momentum, particles): tEth, tf and tp ∝ A0.4 - A0.5 (fig.1)‘Stiff’ temperature profiles (small range of variation of R/LT for large changes in heat) flux : global isotope dependence due to isotope dependence of pedestal propagates to core by ‘stiffness’.Pedestal width in D can be up to twice larger than in H at low gas rate, opposite to expections from neutral penetration (fig.2)Non-linear local GENE gyrokinetic modelling in core reproduces experimental heat fluxes, switching to anti-GyroBohm scaling if effects of collisions, E×B shear and impurities are included.L-mode:Weak dependence of global energy & particle confinement on isotope (∝ A0.15)Stiffness in JETTO-TGLF flux driven modelling overcomes intrinsic GyroBohm dependence in local QL models, leading to no isotope scaling, but not to observed anti-GB scalingDimensionless H/D identity experiment is consistent with scale invariance principle i.e. identical normalised profiles lead to same value for BTtEth/A for both species
(EX/P1-4)
Fig.2
Pedestal
density
A
1/2
D
n
e