SRF2011 - List of Authors (Hicks, D.T.)

Paper	Title	Page
THPO015	Repair SRFCavity by Re-Melting Surface Defects via High Power Laser Technique	740
	G.M. Ge CLASSE, Ithaca, New York, USA E. Borissov, L.D. Cooley, D.T. Hicks, T.H. Nicol, J.P. Ozelis, J. Ruan, D.A. Sergatskov Fermilab, Batavia, USA G. Wu ANL, Argonne, USA
	As the field emission is gradually under control in recent SRF activities, cavity performance is limited by hard quench in the most case. Surface defect has been identified as one of main reasons caused cavity quench scattering cavity accelerating gradient from 12 MV/m to 40 MV/m. Laser processing is able to re-shape the steep flaws to be flat and smooth surface. In Fermilab, a sophisticated laser repair system has been built for 1.3GHz low performance SRF cavity which is limited by surface defect. The pit in a 1.3GHz single-cell cavity was re-melted by high power laser pulse, cavity took 30 μm light Electropolishing after that. The gradient achieved 39MV/m in initial run; after another 30 μm Electropolishing, it achieved 40 MV/m. The improved laser repair system is able to re-melt the surface defect in one meter long 9-cell SRF cavity. It successfully re-melted a pit in 9-cell SRF cavity TB9ACC017.

Paper

Title

Page

Repair SRFCavity by Re-Melting Surface Defects via High Power Laser Technique

740

G.M. Ge
CLASSE, Ithaca, New York, USA
E. Borissov, L.D. Cooley, D.T. Hicks, T.H. Nicol, J.P. Ozelis, J. Ruan, D.A. Sergatskov
Fermilab, Batavia, USA
G. Wu
ANL, Argonne, USA

As the field emission is gradually under control in recent SRF activities, cavity performance is limited by hard quench in the most case. Surface defect has been identified as one of main reasons caused cavity quench scattering cavity accelerating gradient from 12 MV/m to 40 MV/m. Laser processing is able to re-shape the steep flaws to be flat and smooth surface. In Fermilab, a sophisticated laser repair system has been built for 1.3GHz low performance SRF cavity which is limited by surface defect. The pit in a 1.3GHz single-cell cavity was re-melted by high power laser pulse, cavity took 30 μm light Electropolishing after that. The gradient achieved 39MV/m in initial run; after another 30 μm Electropolishing, it achieved 40 MV/m. The improved laser repair system is able to re-melt the surface defect in one meter long 9-cell SRF cavity. It successfully re-melted a pit in 9-cell SRF cavity TB9ACC017.