| Paper | Title | Page |
|---|---|---|
| TUPPO085 | Modification on Surface Oxide Layer Structure and Surface Morphology of Niobium by GCIB Treatments | 436 |
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Recently, it was demonstrated1 that significant reductions in field emission on Nb surfaces could be achieved by means of a new surface treatment technique called gas cluster ion beam (GCIB). Further study revealed that GCIB treatments could also modify surface irregularities and remove surface asperities leading to a smoother surface finish as demonstrated through measurements using a 3-D profilometer, an atomic force microscope, and a scanning electron microscope. These experimental observations were supported by computer simulation via atomistic molecular dynamics and a phenomenological surface dynamics. Measurements employing a secondary ion mass spectrometry found that GCIB could also alter Nb surface oxide layer structure. Possible implications of the experimental results on the performance of Nb superconducting radio frequency cavities treated by GCIB will be discussed. 1: A.T. Wu et al, invited contribution to the book “Neural Computation and Particle Accelerators: Research, Technology, and Applications”, NOVA Science Publishers, New York, USA, 2009, In press |