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Abstract. We have carried out experiment which has important implication on the nature of particle transport. Our analysis of plsama fluctuations in the edge of ADITYA tokamak shows different nature of particle transport at small and large scales. From the Levy analysis, we have shown that fluctuations at small scales (time < 40 micro-sec and length about a few cm) are self-similar with Levy scale index of 1.11. Fluctuations at larger scales are also self-similar with the Levy scale index of 2.0. The observation implies the existence of coherent structures embedded in random fluctuations. The coherent structure may play a central role in explaining the observed bursty transport in the SOL plasma without any need to invoke the standard Self-Organised Criticality (SOC) model. Our measurement of quiet times between successive pulses of potential fluctuations in the time series shows a power-law dependence indicating correlated pulses. This is a further indication of the inappropriateness of the standard SOC model which predict random un-correlated pulses. Upgradation of ADITYA with 20-40 MHz, 200 kW ICRH and 28 GHz, 200 kW ECRH systems will also be described.
IAEA 2003
