Experiments in which very localized electron cyclotron heating (ECH) isscanned through the RTP plasma show sharp transitions, in which theelectron temperature profile abruptly changes shape. The phenomenology - theprofiles shapes, the sharp transitions - can be reproduced with atransport model which features electron transport barriers near all (half-)integer q values. This model is tested against ECH deposition scans in sevenseries of typically 60 discharges. Between the series qa and <ne> werevaried: 4<qa<10 and 1.5<<ne>×1019 m-3<4.5. For a single scan, the model parameters are fixed. The model is capable of reproducing alldata sets. A sensitivity analysis shows that the determination of thestrength of the barriers at integer q values is very stable. These barriersshow a trend χe(barrier)~<ne>-1, whilethe dependence on qa is weak. The model reproduces the <ne> and qa components of L-mode scaling of global confinement.
Electron dynamics and the enhancement of Q in mirror-magnetic wells