LINAC2014 - List of Authors (Geng, R.L.)

Paper

Title

Page

Analysis of New High-Q0 SRF Cavity Tests by Nitrogen Gas Doping at Jefferson Lab

736

A.D. Palczewski, R.L. Geng, C.E. Reece
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In order to refine systematic understanding and establish confident process control, Jefferson Lab has joined with partners to investigate and thoroughly characterize the dramatically higher Q0 of 1.3 GHz niobium cavities first reported by FNAL in 2013[1]. With partial support from the LCLS-II project, JLab has undertaken a parametric study of nitrogen doping in vacuum furnace at 800 C followed by variable depth surface removal in the 5 - 20 μm range. Q0 above 3×10¹⁰ are typical at 2.0 K and 16 MV/m accelerating field. We report observations from the single cell study and current interpretations. In addition to the parametric single cell study, we also report on the ongoing serial testing of six nitrogen-doped 9-cell cavities as baseline prototypes for LCLS-II.
[1] A. Grassellino, et al., Supercon. Sci.and Tech., 2013. 26(10): p. 102001

Poster TUPP138 [4.214 MB]

THPP100

Result of MHI 2-Cell Seamless Dumb-Bell Cavity Vertical Test

1087

K. Okihira, H. Hara, N. Ikeda, F. Inoue, K. Sennyu
MHI, Hiroshima, Japan
R.L. Geng, R.A. Rimmer
JLab, Newport News, Virginia, USA
E. Kako
KEK, Ibaraki, Japan

MHI have supplied several 9-cell cavities for STF (R&D of ILC project at KEK) and have been considering production method for stable quality and cost reduction, seamless dumb-bell cavity was one of them. We had fabricated a 2 cell seamless dumb-bell cavity for cost reduction and measured RF performance in collaboration with JLab, KEK and MHI. Surface treatment recipe for ILC was applied for MHI 2-cell cavity and vertical test was performed at JLab. The cavity reached Eacc=32.4MV/m after BCP and EP. Details of the result are reported.

Paper	Title	Page
TUPP138	Analysis of New High-Q0 SRF Cavity Tests by Nitrogen Gas Doping at Jefferson Lab	736
	A.D. Palczewski, R.L. Geng, C.E. Reece JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. In order to refine systematic understanding and establish confident process control, Jefferson Lab has joined with partners to investigate and thoroughly characterize the dramatically higher Q0 of 1.3 GHz niobium cavities first reported by FNAL in 2013[1]. With partial support from the LCLS-II project, JLab has undertaken a parametric study of nitrogen doping in vacuum furnace at 800 C followed by variable depth surface removal in the 5 - 20 μm range. Q0 above 3×10¹⁰ are typical at 2.0 K and 16 MV/m accelerating field. We report observations from the single cell study and current interpretations. In addition to the parametric single cell study, we also report on the ongoing serial testing of six nitrogen-doped 9-cell cavities as baseline prototypes for LCLS-II. [1] A. Grassellino, et al., Supercon. Sci.and Tech., 2013. 26(10): p. 102001
	Poster TUPP138 [4.214 MB]

THPP100	Result of MHI 2-Cell Seamless Dumb-Bell Cavity Vertical Test	1087
	K. Okihira, H. Hara, N. Ikeda, F. Inoue, K. Sennyu MHI, Hiroshima, Japan R.L. Geng, R.A. Rimmer JLab, Newport News, Virginia, USA E. Kako KEK, Ibaraki, Japan
	MHI have supplied several 9-cell cavities for STF (R&D of ILC project at KEK) and have been considering production method for stable quality and cost reduction, seamless dumb-bell cavity was one of them. We had fabricated a 2 cell seamless dumb-bell cavity for cost reduction and measured RF performance in collaboration with JLab, KEK and MHI. Surface treatment recipe for ILC was applied for MHI 2-cell cavity and vertical test was performed at JLab. The cavity reached Eacc=32.4MV/m after BCP and EP. Details of the result are reported.