Mikrowelt: Nonlineare Diffusionsprozesse
62 per cent of the energy used for plasma heating was re-gained by the fusion reaction ("Q-factor" 0.62) - practically the physical proof of the functioning of the concept.
The product of temperature, density and confinement time is an important criterium of fusion physics. In order to reach reactor conditions, it has yet to be improved by a factor of about 6. When compared with the progress of the past decades, this seems to be a rather small (though expensive) step.