Accepted author manuscript, 1.59 MB, PDF document
Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Accepted author manuscript, 1.52 MB, PDF document
Available under license: CC BY: Creative Commons Attribution 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Review article › peer-review
Research output: Contribution to Journal/Magazine › Review article › peer-review
}
TY - JOUR
T1 - Devices for SRF material characterization
AU - Goudket, P.
AU - Junginger, T.
AU - Xiao, B. P.
N1 - This is an author-created, un-copyedited version of an article accepted for publication/published in Superconductor Science and Technology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it.
PY - 2016/11/15
Y1 - 2016/11/15
N2 - The surface resistance R s of superconducting materials can be obtained by measuring the quality factor of an elliptical cavity excited in a transverse magnetic mode (TM010). The value obtained has however to be taken as averaged over the whole surface. A more convenient way to obtain R s, especially of materials which are not yet technologically ready for cavity production, is to measure small samples instead. These can be easily manufactured at low cost, duplicated and placed in film deposition and surface analytical tools. A commonly used design for a device to measure R s consists of a cylindrical cavity excited in a transverse electric (TE110) mode with the sample under test serving as one replaceable endplate. Such a cavity has two drawbacks. For reasonably small samples the resonant frequency will be larger than frequencies of interest concerning SRF application and it requires a reference sample of known R s. In this article we review several devices which have been designed to overcome these limitations, reaching sub-nΩ resolution in some cases. Some of these devices also comprise a parameter space in frequency and temperature which is inaccessible to standard cavity tests, making them ideal tools to test theoretical surface resistance models.
AB - The surface resistance R s of superconducting materials can be obtained by measuring the quality factor of an elliptical cavity excited in a transverse magnetic mode (TM010). The value obtained has however to be taken as averaged over the whole surface. A more convenient way to obtain R s, especially of materials which are not yet technologically ready for cavity production, is to measure small samples instead. These can be easily manufactured at low cost, duplicated and placed in film deposition and surface analytical tools. A commonly used design for a device to measure R s consists of a cylindrical cavity excited in a transverse electric (TE110) mode with the sample under test serving as one replaceable endplate. Such a cavity has two drawbacks. For reasonably small samples the resonant frequency will be larger than frequencies of interest concerning SRF application and it requires a reference sample of known R s. In this article we review several devices which have been designed to overcome these limitations, reaching sub-nΩ resolution in some cases. Some of these devices also comprise a parameter space in frequency and temperature which is inaccessible to standard cavity tests, making them ideal tools to test theoretical surface resistance models.
KW - SRF thin film testing cavities
KW - superconducting RF
KW - thin film characterisation
U2 - 10.1088/0953-2048/30/1/013001
DO - 10.1088/0953-2048/30/1/013001
M3 - Review article
AN - SCOPUS:84999864972
VL - 30
JO - Superconductor Science and Technology
JF - Superconductor Science and Technology
SN - 0953-2048
IS - 1
M1 - 013001
ER -