Creation and control of variably shaped plasmas in TCV

During the first year of operation, the TCV tokamak has produced a large variety of plasma shapes and magnetic configurations, with 1.0≤Btor≤1.46T, Ip≤800kA, k≤2.05, -0.7≤δ ≤0.7. A new shape control algorithm, based on a finite element reconstruction of the plasma current in real time, has been implemented. Vertical growth rates of 800 sec-1, corresponding to a stability margin f=1.15, have been stabilized. Ohmic H-modes, with energy confinement times reaching 80ms, normalized beta (βtor aB/Ip) of 1.9 and τE/ITER89-P of 2.4 have been obtained in single-null X-point deuterium discharges with the ion grad B drift towards the X-point. Limiter H-modes with maximum line averaged electron densities of 1.7x1020m-3 have been observed in D-shaped plasmas with 360kA≤Ip≤600kA. (Author)