Plasma Start-Up Measurements in the Toroidal Plasma Experiment TJ-K

The torsatron TJ-K confines a toroidal low-temperature plasma, which is accessible for Langmuir probes throughout the whole confinement region. With the Langmuir-probe array ldquoSPIDERrdquo, spatially and temporally resolved profiles of the plasma density can be measured in the poloidal cross section in order to observe dynamical processes in the plasma. Thus, a complete plasma start-up from neutral gas up to the plasma equilibrium can be visualized, which allows one to draw conclusions on heating processes.