ELECTROSTATIC AND MAGNETIC TURBULENCE IN THE TJ-I TOKAMAK

Electrostatic and magnetic turbulence has been investigated in the edge region of the TJ-I tokamak using Langmuir and magnetic probes. The relative levels for density fluctuations are in the range ˜/n ≈ 0.4–0.8 and for magnetic fluctuations ˜/Bt ≈ 5 × 10−5. Density and potential fluctuations do not scale in the same way as a function of plasma radius (i.e. ˜/n ≠ e˜/Te). The particle confinement time inferred from electrostatic fluctuations is found to increase with increasing magnetic field and electron density. The global particle confinement times estimated from absolute Hα emission intensity measurements are in good agreement with the particle confinement times inferred from electrostatic fluctuations. The contribution of magnetic fluctuations to the edge particle transport is negligible. © 1990 IOP Publishing Ltd.