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Title: Comparison of Q0 in different materials.


Abstract not provided.

; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Resource Relation:
Conference: Proposed for presentation at the Quantum Computing Program Review held July 18-21, 2016 in Arlington, VA.
Country of Publication:
United States

Citation Formats

Rudolph, Martin, Carroll, Malcolm S., and Zimmerman, Neil. Comparison of Q0 in different materials.. United States: N. p., 2016. Web.
Rudolph, Martin, Carroll, Malcolm S., & Zimmerman, Neil. Comparison of Q0 in different materials.. United States.
Rudolph, Martin, Carroll, Malcolm S., and Zimmerman, Neil. Sat . "Comparison of Q0 in different materials.". United States. doi:.
title = {Comparison of Q0 in different materials.},
author = {Rudolph, Martin and Carroll, Malcolm S. and Zimmerman, Neil},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Oct 01 00:00:00 EDT 2016},
month = {Sat Oct 01 00:00:00 EDT 2016}

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  • The improvement of the quality factor Q{sub 0} of superconducting radio-frequency (SRF) cavities at medium accelerating gradients ({approx} 20 MV/m) is important in order to reduce the cryogenic losses in continuous wave accelerators for a variety of applications. In recent years, SRF cavities fabricated from ingot niobium have become a viable alternative to standard high-purity fine-grain Nb for the fabrication of high-performing SRF cavities with the possibility of significant cost reduction. Initial studies demonstrated the improvement of Q{sub 0} at medium field in cavities heat treated at 800-1000 C without subsequent chemical etching. To further explore this treatment procedure, amore » new induction furnace with an all-niobium hot-zone was commissioned. A single-cell 1.5 GHz cavity fabricated from ingot material from CBMM, Brazil, with RRR {approx} 200, was heat treated with the new furnace in the temperature range 600-1200 C for several hours. Residual resistance values 1-5 nano-ohm have been consistently achieved on this cavity as well as Q{sub 0} values above {approx} 2 x 10{sup 11} at 2 K and 100 mT peak surface magnetic field. Q{sub 0}-values of the order of 10{sup 11} have been measured at 1.5 K.« less
  • No abstract prepared.
  • As reported previously at the Berlin workshop, applying the JLab standard ILC electropolishing (EP) recipe on previously buffered chemical polishing (BCP) etched fine-grain multi-cell cavities results in improvement both in gradient and Q{sub 0}. We recently had the opportunity to experiment with two 1300 MHz 9-cell large-gain niobium cavities manufactured by JLab and Peking University. Both cavities were initially BCP etched and further processed by using JLab's standard ILC EP recipe. Due to fabrication defects, these two cavities only reached a gradient in the range of 20-30 MV/m. Interestingly both cavities demonstrated significant Q{sub 0} improvement in the gradient rangemore » of 15-20 MV/m. At 2K, a Q{sub 0} value of 2E10 is achieved at 20 MV/m. At a reduced temperature of 1.8K, a Q{sub 0} value of 3E10 is achieved at 20 MV/m. These results suggest that a possible path for obtaining higher Q{sub 0} in the medium gradient range is to use the large-grain material for cavity fabrication and EP and low temperature bake for cavity processing.« less