Statistical analysis on the intermittency and turbulent particle transport on the HL-2A tokamak

By the calculation of particle probability distribution function, it is found that the frequency of intermittency breakout increases at the edge of higher density plasmas. Positive and negative breakouts of intermittency are distinguished using a conditional average algorithm, indicating that positive and negative intermittency events have different space characteristics. It is also demonstrated that existence of intermittent events greatly enhances the turbulence particle transport by computing the turbulent particle transport at different gradients of fluctuating densities. At higher densities, the enhancement of intermittency roughly accounts for the increase of turbulent particle transport. (authors)