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 |
|---|---|
| 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 2005 |
| Externally published | Yes |
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Keywords
- Cluster beam
- Cluster-surface interactions
- Kilpatrick limit
- RF breakdown
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Instrumentation
- Surfaces and Interfaces
Cite this
Smoothing RF cavities with gas cluster ions to mitigate high voltage breakdown. / Swenson, D. R.; Degenkolb, E.; Insepov, Z.; Laurent, L.; Scheitrum, G.
In: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, Vol. 241, No. 1-4, 12.2005, p. 641-644.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Smoothing RF cavities with gas cluster ions to mitigate high voltage breakdown
AU - Swenson, D. R.
AU - Degenkolb, E.
AU - Insepov, Z.
AU - Laurent, L.
AU - Scheitrum, G.
PY - 2005/12
Y1 - 2005/12
N2 - 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.
AB - 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.
KW - Cluster beam
KW - Cluster-surface interactions
KW - Kilpatrick limit
KW - RF breakdown
UR - http://www.scopus.com/inward/record.url?scp=28044436938&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=28044436938&partnerID=8YFLogxK
U2 - 10.1016/j.nimb.2005.07.107
DO - 10.1016/j.nimb.2005.07.107
M3 - Article
VL - 241
SP - 641
EP - 644
JO - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
JF - Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
SN - 0168-583X
IS - 1-4
ER -