Tl. Rhodes et al., SCALING OF FAR EDGE PLASMA TURBULENCE AND FLUCTUATION-INDUCED PARTICLE-TRANSPORT IN THE TEXT TOKAMAK, Nuclear fusion, 33(8), 1993, pp. 1147-1163
Scaling studies of turbulence and turbulence induced particle transpor
t have been performed in the edge plasma of the TEXT tokamak using Lan
gmuir probes and a fast probe drive: Emphasis was placed on examining
possible free energy sources, such as the local density and temperatur
e gradients. To first order, the fluctuation levels n(e)/n(e) and phi(
f)/T(e) are not linear functions of either the electron density or ele
ctron temperature gradient drives alone. The density fluctuation level
n(e)/n(e) scales approximately as B-1, while the fluctuation induced
particle flux GAMMA(nphi) scales as n(e)B-2+/-1 in the edge plasma and
as n(e)0B-2+/-1 in the scrape-off layer. Here, B and n(e) are the mag
netic field and the local density, respectively. The mean poloidal wav
enumber k(theta)BAR varies approximately as the inverse ion Larmor rad
ius rho(s)-1, with k(theta)rho(s)BAR congruent-to 0.04. Comparison is
made with theoretical predictions.