IPAC2011 - List of Authors (Sawabe, M.)

Paper	Title	Page
MOPC092	Effect of Current Densities on Sulfur Generation at Electropolished Niobium Surface	292
	P.V. Tyagi Sokendai, Ibaraki, Japan H. Hayano, S. Kato, M. Nishiwaki, T. Noguchi, T. Saeki, M. Sawabe KEK, Ibaraki, Japan
	We conducted a series of electropolishing (EP) experiments in aged EP acid with high (≈50 mA/cm²) and low (≈30 mA/cm²) current densities on Nb surfaces. The experiments were carried out both for laboratory coupons and a real Nb single cell cavity with six witness samples located at three typical positions (equator, iris and beam pipe). All the samples surface were investigated by XPS (x-ray photoelectron spectroscopy), SEM (scanning electron microscope) and EDX (energy dispersive x-ray spectroscopy). The surface analysis showed the EP with a high current density produced a huge amount sulfate particles at Nb surface whereas the EP with a low current density is very helpful to mitigate sulfate at Nb surface in both the experiments.

Paper

Title

Page

Effect of Current Densities on Sulfur Generation at Electropolished Niobium Surface

292

P.V. Tyagi
Sokendai, Ibaraki, Japan
H. Hayano, S. Kato, M. Nishiwaki, T. Noguchi, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan

We conducted a series of electropolishing (EP) experiments in aged EP acid with high (≈50 mA/cm²) and low (≈30 mA/cm²) current densities on Nb surfaces. The experiments were carried out both for laboratory coupons and a real Nb single cell cavity with six witness samples located at three typical positions (equator, iris and beam pipe). All the samples surface were investigated by XPS (x-ray photoelectron spectroscopy), SEM (scanning electron microscope) and EDX (energy dispersive x-ray spectroscopy). The surface analysis showed the EP with a high current density produced a huge amount sulfate particles at Nb surface whereas the EP with a low current density is very helpful to mitigate sulfate at Nb surface in both the experiments.