In this talk we will introduce a new effort at Sandia to better understand the mechanisms involved in vacuum field emission from real, contaminated surfaces. We concentrate on the vacuum field emission of electrons from a surface based strongly on the role of initial emission as a necessary precursor to vacuum discharge. Although other ongoing work at Sandia is concerned with the evolution of...
High-field and breakdown experiments are being carried out at CERN using a pulsed dc set-up. The objective of the pulsed dc experiments are to complement the ongoing high-gradient radio frequency experimental program and for optimizing material treatments, parameters of conditioning process and methods of minimization of breakdown events in accelerating structures. The latest hardware...
A spectrometer for detection of the dark and breakdown currents during conditioning of new accelerating structures for CLIC, is operated at one of the 12 GHz stand-alone test-stands at CERN. The spectrometer consists of a dipole magnet, a variable collimator, and a fluorescent screen read out by a fast camera.
Built for high repetition rate operation it can measure the spatial and energy...
This presentation aims to provide brief updates on our current understanding of the theory of field electron emission (FE), on progress in putting FE theory onto a more scientific basis, and on progress in interpreting measured FE current-voltage [Im(Vm)] characteristics. Possibly the main use of FE theory in vacuum breakdown is to provide good formulae for use in simulators, with some...
Electron emission from nanometric emitters becomes increasingly interesting due to its involvement to vacuum breakdown phenomena and various other vacuum nanoelectronics applications. The most commonly used theoretical tool for the calculation of electron emission is still nowadays the Fowler-Nordheim (F-N) equation, although it has been shown that it is inadequate for nanometrically sharp...
