Effect of the relative shift between the electron density and temperature pedestal position on the pedestal stability in JET-ILW

摘要

1. INTRODUCTION The pedestal structure and its stability affect the performance of a tokamak fusion device. As it has been already observed in DIII-D in [1], the electron temperature (T_e) and density (n_e) pedestals tend to vary in their relative positions in correlation with p*. Change in the relative positions seem to have an impact on the pedestal MHD stability and hence on the pedestal height [2]. This work investigates the effects of the relative pedestal positions on the stability of JET-ILW. It shows that the increase of the pedestal relative shift is correlated with the reduction in the normalized pressure gradient. Experimental results are then compared with the peeling-ballooning (P-B) model. Normalized pressure gradient is then also calculated for extended dataset of JET-ILW baseline low δ pulses and compared with low 8 JET-C pulses.