observation of the hard disruption instability in the ir-ti (iran-tokamak 1)

in this article, some diagnostic systems and the preliminary results of the ir-t1** (iran-tokamak 1) are presented. different diagnostic methods, including an array of soft x-ray detectors, visible spectrometer, electron cyclotron emission detector and electromagnetic measurement systems have been used and the hard disruptive instability occurring in the ir-t1 plasma during an ohmic heating discharge, under a range of reproducible conditions for 3 q(a) 2, is studied. it is found that the disruption activity occurs when the value of the safety factor at the plasma edge becames less than q(a) 2.7.