Isotope Dependence of Confinement in JET Deuterium and

Isotope Dependence of Confinement in JET Deuterium and Hydrogen Plasmas (EX/P 1 -4) • • • 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): t. Eth, tf and tp ∝ A 0. 4 - A 0. 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-Gyro. Bohm scaling if effects of collisions, E×B shear and impurities are included. regression Type I ELMy H-mode in hydrogen and deuterium: Fig. 1 Log thermal energy • • Weak dependence of global energy & particle confinement on isotope (∝ A 0. 15) Stiffness in JETTO-TGLF flux driven modelling overcomes intrinsic Gyro. Bohm dependence in local QL models, leading to no isotope scaling, but not to observed anti-GB scaling Dimensionless H/D identity experiment is consistent with scale invariance principle i. e. identical normalised profiles lead to same value for BTt. Eth/A for both species A 1/2 Dn • e L-mode: Fig. 2 Pedestal density 1