The performance and efficiency of the future linear accelerators is determined by the quality of the RF structures used to accelerate the particle beams. This quality is affected by the inner surface of the structures which are subject to field emission of electrons and even cause vacuum breakdowns at the desired high acceleration gradients. Better understanding of the mechanism of the forming...
Field emission (FE) from high-voltage electrode surfaces governs arc breakdown processes in the limit of microscale electrode spacings. In this regime, microscopic features of the electrode surface exert an influence on emitted electrons via local field enhancement at high-aspect-ratio features and work function variation. However, the tendency for surface charge distributions to alter the...
(abstract forthcoming)
Dark current (undesirable field emission electron current) is proven to be one of electric breakdown triggers. Breakdowns are accompanied with x-ray flashes and ion-electron plasma bursts. At the breakdown location the material is often damaged – it is caused to melt, flow and re-crystallize – which indirectly suggests exceedingly high temperature at those locations. Breakdowns happen at...
The dynamics of dislocation activity under intense electric fields has been proposed as a potential cause of breakdowns. In this talk, results of searches for high-frequency fluctuations in field-emitted current that could arise as a consequence of these dynamics are presented for high-gradient RF accelerating structures and pulsed DC experiments at CERN. Measurements of spatial profiles of...
