Compact Plasma and Focused Ion Beams

251Electron Localization and Trapping PhysicsRevisited

180 W, 0.25 mTorr. At initial times (~5 μs), the electrons are nearly uniformly

distributed. With time, the electrons gradually become phase-locked with

the SW pattern, and at ~20 μs, well-dened striations are obtained. At SW

maxima (z ~ 5, 11.5, 18 cm), the electrons are accelerated more and hence

gain higher velocity, which is clearly observed in the plots (Figure 15.7a

throughd), and also demonstrate higher velocity spread compared to the

minima. The higher velocity spread at SW maxima is consistent with the

experimental variation of electron energy spread (Figure 15.3a).

Figure 15. ...