  The properties of plasma turbulence in a poloidally limited scrape-off layer
(SOL) are addressed, with focus on ISTTOK, a large aspect ratio tokamak with a
circular cross section. Theoretical investigations based on the drift-reduced
Braginskii equations are carried out through linear calculations and non-linear
simulations, in two- and three-dimensional geometries. The linear instabilities
driving turbulence and the mechanisms that set the amplitude of turbulence as
well as the SOL width are identified. A clear asymmetry is shown to exist
between the low-field and the high-field sides of the machine. A comparison
between experimental measurements and simulation results is presented.
