Spectroscopic observations of a reversed field pinch: Eta-Beta II

The XUV and visible spectrum emitted by the RFP plasma produced in the Eta-Beta II experiment is investigated by spectroscopic measurements. The concentration of the impurity species present in the plasma is estimated, leading to an effective charge <or approximately=1.5. Electron and ion temperatures are measured by line intensity ratio and Doppler broadening respectively, and Te approximately=Ti is found. Finally, the experimental results are discussed on the basis of a zero-dimensional time-dependent model for the emitting plasma.