Impurities are injected into JET and Tore Supra by the laser blow-off ablation technique for a variety of experimental situations. The impurity confinement times τp, which reflect the impurity transport, have been measured by fitting exponential curves to the decays of the central brightnesses. Two databases are built up, including ohmic and L mode discharges, with the aim of determining a τp scaling law common to both devices. Different monomial scaling laws are tested and the best one is chosen on the basis of minimization of the standard deviation of the individual regressions. Moreover, the impurity confinement times are compared with the energy confinement times τE for the same data. The energy confinement times are larger than the impurity confinement times, the average ratio tau E/τp being approximately 2.5

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Experimental neon spectra (in the 10-nm region), from the tokamak Tore Supra and the reversed field pinch experiment RFX, have been simulated. The spectra include lines from three neon ionization states, namely Ne(7+), Ne(6+), and Ne(5+) ions. Collisional radiative models have been built for these three Ne ions, considering electron collisional excitation and radiative decay as populating processes of the excited states. These models give photon emission coefficients for the emitted lines at electron density and temperature values corresponding to the experimental situations. Impurity modelling is performed using a one-dimensional impurity transport code, calculating the steady-state radial distribution of the Ne ions. The Ne line brightnesses are evaluated in a post-process subroutine and simulated spectra are obtained. The parts of the spectra corresponding to a single ionization state do not depend on the experimental conditions and show good agreement with the simulated single ionization state spectra. On the other hand, the superposition of the three spectra depends on the experimental conditions, as a consequence of the fact that the ion charge distribution depends not only on the radial profiles of the electron density and temperature, but also of the impurity transport coefficients. Simulations of the Ne spectra (including transport) give confidence in the atomic physics calculations; moreover, they allow the determination of the transport coefficients in the plasma region emitting the considered ionization states.

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