1. Isotope Dependence of Confinement in JET Deuterium and Hydrogen Plasmas
(EX/P1-4)
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 - A (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 scaling
Dimensionless 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
Fig.1 Log thermal energy
regression
Fig.2 Pedestal density
A1/2Dne