Study of Edge Plasma Perturbations Induced by Sawtooth Crash on CHS

In the CHS heliotron/torsatron, using a Langmuir probe array, we measured the edge plasma fluctuations during sawtooth oscillations. Ion saturation current, floating potential and their fluctuations are modulated by sawtooth crashes. The fluctuations are enhanced almost similarly from low frequency part (f - 2kHz) to high frequency part (f - 100 kHz).