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Review of High Field Q Slope, Cavity Measurements.

DE2008922270

Publication Date	2008
Personal Author	Ciovati, G.
Page Count	5
Abstract	One of the most interesting phenomenon occurring in superconducting radio-frequency (SRF) cavities made of bulk niobium is represented by a sharp decrease of the quality factor above peak surface magnetic field of about 90 mT and is referred to as 'high field Q-slope' or 'Q-drop'. This phenomenon was observed first in 1997 and since then some effort was devoted to the understanding of the causes behind it. Still, no clear physical interpretation of the Q-drop has emerged, despite several attempts. In this contribution, I will review the experimental results for various cavities measured in many laboratories and I will try to identify common features and differences related to the Q-drop.
Keywords	Superconducting radio-frequency cavities Cavity measurements Q slope Q drop Superconducting radio-frequency (SRF)
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Thomas Jefferson National Accelerator Facility, Newport News, VA.; Department of Energy, Washington, DC. Office of Science.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC. Office of Science.
Document Type	Technical Report
NTIS Issue Number	200813
Contract Number	AC05-06OR23177

Review of High Field Q Slope, Cavity Measurements.

Review of High Field Q Slope, Cavity Measurements.
DE2008922270

Publication Date	2008
Personal Author	Ciovati, G.
Page Count	5
Abstract	One of the most interesting phenomenon occurring in superconducting radio-frequency (SRF) cavities made of bulk niobium is represented by a sharp decrease of the quality factor above peak surface magnetic field of about 90 mT and is referred to as 'high field Q-slope' or 'Q-drop'. This phenomenon was observed first in 1997 and since then some effort was devoted to the understanding of the causes behind it. Still, no clear physical interpretation of the Q-drop has emerged, despite several attempts. In this contribution, I will review the experimental results for various cavities measured in many laboratories and I will try to identify common features and differences related to the Q-drop.
Keywords	Superconducting radio-frequency cavities Cavity measurements Q slope Q drop Superconducting radio-frequency (SRF)
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Thomas Jefferson National Accelerator Facility, Newport News, VA.; Department of Energy, Washington, DC. Office of Science.
Supplemental Notes	Sponsored by Department of Energy, Washington, DC. Office of Science.
Document Type	Technical Report
NTIS Issue Number	200813
Contract Number	AC05-06OR23177