First plasmas in Heliotron J

Results obtained in the initial experimental phase of Heliotron J are repor ted. Electron beam mapping of the magnetic surfaces at a reduced DC magneti c field lias revealed that the observed surfaces are in basic agreement wit h the ones calculated on the basis of the measured ambient field around the device. For 53.2 GHz second harmonic ECH hydrogen plasmas, a fairly wide r esonance range for breakdown and heating by the TE02 mode has been observed in Heliotron J as compared with that in Heliotron E. With ECH injection po wers up to approximate to 400 kW, diamagnetic stored energies up to approxi mate to0.7 kJ were obtained without optimized density control.