Probability distribution functions for intermittent scrape-off layer plasma fluctuations

Stochastic modeling of intermittent scrape-off layer plasma fluctuations.

Single-point measurements of fluctuations in the scrape-off layer of magnetized plasmas are generally found to be dominated by large-amplitude bursts which are associated with radial motion of bloblike structures. A stochastic model for these fluctuations is presented, with the plasma density given by a random sequence of bursts with a fixed wave form. When the burst events occur in accordance ...

Intermittent fluctuations in the TCV scrape-off layer

Probe measurements in the scrape-off layer of tokamak plasmas show that the ion saturation current signal is dominated by large amplitude bursts. Analysis of data time series from tokamak á configuration variable of unprecedented duration reveals that both burst amplitudes and waiting times are exponentially distributed. The average burst wave form has an exponential shape with a characteristic...

Plasma shaping effects on tokamak scrape-off layer turbulence

The impact of plasma shaping on tokamak scrape-off layer (SOL) turbulence is investigated. The drift-reduced Braginskii equations are written for arbitrary magnetic geometries, and an analytical equilibrium model is used to introduce the dependence of turbulence equations on tokamak inverse aspect ratio ( ), Shafranov’s shift (∆), elongation (κ), and triangularity (δ). A linear study of plasma ...

Modeling of supersonic plasma flow in the scrape-off layer

The substantial drop of the plasma temperature along magnetic field lines with increasing plasma density is one of the main features in tokamak divertors. As a result the temperature gradient at the divertor plates becomes very steep and the boundary condition normally applied for the parallel Mach number M at the target, Mt = 1, cannot be satisfied. In this case the value of Mt based on the ge...

Aspect ratio effects on limited scrape-off layer plasma turbulence