IPAC2011 - List of Authors (Leifer, K.)

Paper	Title	Page
TUPS097	In-situ Experiments of Vacuum Discharge using Scanning Electron Microscopes	1765
	T. Muranaka, V.G. Ziemann Uppsala University, Uppsala, Sweden T. Blom, K. Leifer Uppsala University, Department of Engineering Sciences, Uppsala, Sweden
	Funding: This work is supported by the 7th European Framework Program EuCARD under grant number 227579 Fundamental understandings of vacuum discharge mechanisms and involving surface damage is an indispensable for CLIC feasibility study. We have been conducting dc experiments inside a Scanning Electron Microscope (SEM) at Uppsala university in order to investigate localised breakdown phenomena. By using a SEM, we achieve the resolution of the electron probe in the few-nm range, which is of great advantage as the surface roughness of the polished accelerating structures is in the same scale. The high accelerating field of 1 GV/m is realised by biasing an electrode with 1 kV set above the sample with a gap of sub μm. Furthermore, a second SEM equipped with a Focused Ion Beam (FIB) is used to modify the topography of sample surfaces thus the geometrical dependence of field emissions and vacuum discharges could be studied. The FIB can be used for the surface damage analysis as well. We have demonstrated subsurface damage observations by using FIB to sputter a rectangular recess into the sample in the breakdown region. Those powerful surface analysis techniques can be productively applied to the study of fatigue in prototype accelerating structures.

Paper

Title

Page

In-situ Experiments of Vacuum Discharge using Scanning Electron Microscopes

1765

T. Muranaka, V.G. Ziemann
Uppsala University, Uppsala, Sweden
T. Blom, K. Leifer
Uppsala University, Department of Engineering Sciences, Uppsala, Sweden

Funding: This work is supported by the 7th European Framework Program EuCARD under grant number 227579
Fundamental understandings of vacuum discharge mechanisms and involving surface damage is an indispensable for CLIC feasibility study. We have been conducting dc experiments inside a Scanning Electron Microscope (SEM) at Uppsala university in order to investigate localised breakdown phenomena. By using a SEM, we achieve the resolution of the electron probe in the few-nm range, which is of great advantage as the surface roughness of the polished accelerating structures is in the same scale. The high accelerating field of 1 GV/m is realised by biasing an electrode with 1 kV set above the sample with a gap of sub μm. Furthermore, a second SEM equipped with a Focused Ion Beam (FIB) is used to modify the topography of sample surfaces thus the geometrical dependence of field emissions and vacuum discharges could be studied. The FIB can be used for the surface damage analysis as well. We have demonstrated subsurface damage observations by using FIB to sputter a rectangular recess into the sample in the breakdown region. Those powerful surface analysis techniques can be productively applied to the study of fatigue in prototype accelerating structures.