Performance and control of optimized shear discharges in JET

摘要

High performance discharges are routinely obtained on JET with low or reversed magnetic shear(s=(r/q)dq/dr), and the potential for steady state operation of such discharges is under investigation. With the user of the proper heating and fuelling, these `optimized shear'(OS)discharges exhibit an internal transport barrier(ITB), resulting in a strong peaking of the pressure profile, and thus in high fusion performance. These regimes have been extensively studied during the last(DD and DT)JET campaigns in order to promote this type of scenario as the basis for 'advanced tokamak' operation. A review is given of order to highest performance achieved on JET Osdischarges during the last experiental campaigns, in both DD(up to 5.6*10~16 neutrons/s) and DT operation(fusion power up to 8.2 MW,n~i0T~ioTE up to 10~21 m~-3 ke Vs).