Measurements are reported of the average plasma beta of ECRH plasmas in the TJ-IU torsatron using external flux loops. The method is based on measurements of the magnetic flux produced by the Pfirsch-Schluter current due to the plasma pressure. The most important advantages of using this method over the conventional diamagnetic method are much higher relative signal ratio (useful signal owing to plasma beta over the total background signal) and easy installation of the diagnostic in any type of stellarator device. A general description of the technique and its applications to more complicated stellarator devices like TJ-II is also presented
Edge characteristics and global confinement of electron cyclotronresonance heated plasmas in the TJ-II Stellarator