Abstract
Many studies have demonstrated that improving the surface smoothness and cleanliness of high voltage electrodes increases the voltage standoff capability, but none have specifically investigated the role of nano-scale and atomic level surface roughness. Using AFM imaging, we have studied the effect of gas cluster ion beams (GCIB) on oxygen-free Cu electrode material that is used in high gradient RF cavities. Using Ar clusters accelerated by 30 kV, with a dose of 6 × 1014 e cm-2, we have effectively removed an asperity that was 3500 Å wide and 350 Å high. Subsequent processing with 5 kV acceleration reduced the surface roughness from an Ra value of 13.2 Å to 4.8 Å. This demonstrates the effectiveness of GCIB for reducing sub-micron roughness to atom level smoothness.
Original language | English |
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Pages (from-to) | 641-644 |
Number of pages | 4 |
Journal | Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms |
Volume | 241 |
Issue number | 1-4 |
DOIs | |
Publication status | Published - Dec 1 2005 |
Externally published | Yes |
Keywords
- Cluster beam
- Cluster-surface interactions
- Kilpatrick limit
- RF breakdown
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Instrumentation