Integrated numerical analysis of impurity transport and sources for high current—high power baseline pulses with T in JET-ILW

This work consists of integrated numerical modelling applied to JET high-current, high-power baseline pulses with 92% tritium + 8% hydrogen with tungsten divertor and beryllium wall in corner configuration. These simulations are performed using the COREDIV code, which self-consistently solves one-dimensional radial transport equations for the plasma and impurities in the core region, coupled with two-dimensional multi-fluid transport in the scrape-off layer. It should be noted that the simulations are ‘semi-interpretative’, in the sense that transport coefficients are tuned in order to match experimental data: profile of the radiation, Ni concentration, radiation in SOL and Zeff. The simulations suggest that, within the assumptions of the COREDIV model and the available experimental constraints, the observed increase in core plasma radiation can be most consistently reproduced by changes in impurity transport rather than by an increase in the impurity source. The simulations show that sputtering of tungsten due to tritium is negligible. The Be is the main source of sputtering and the dominant contribution to tungsten sputtering comes from Be2+.