Production of superconducting 1.3-GHz cavities for the European X-ray Free Electron Laser

Singer, W.; Brinkmann, A.; Brinkmann, R.; Iversen, J.; Matheisen, A.; Moeller, Wolf‐Dietrich; Navitski, A.; Reschke, D.; Schaffran, Joern; Сулимов, А. А.; Walker, Nick; Weise, H.; Michelato, P.; Monaco, Laura; Pagani, C.; Wiencek, Mateusz

doi:10.1103/physrevaccelbeams.19.092001

Cited by 38 publications

(39 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…accelerating gradient compared to flash BCP-treated cavities [24]. The combination of nitrogen doping and optimal electropolishing resulted in higher quality factor increasing with the accelerating gradient before it quenched at lower gradient compared to baseline EP/BCP cavities.…”

Section: Discussionmentioning

confidence: 91%

Surface characterization of nitrogen-doped high purity niobium coupons compared with superconducting rf cavity performance

Dhakal

Ciovati

Pudasaini

et al. 2019

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

We report the results from the measurements of high purity Nb samples and superconducting radiofrequency (SRF) cavities doped with nitrogen and followed by either electropolishing (EP) or buffered chemical polishing (BCP), in order to understand the role of the postdoping treatment on the performance of SRF cavities. The samples characterization via scanning electron microscope, x-ray photoelectron spectroscopy and secondary ion mass spectroscopy showed topographical differences on the surface of the samples after EP versus BCP treatment, but similar surface composition. Radio-frequency measurements were done on single cell cavities made from fine-grain and large-grain Nb treated by nitrogen doping followed by BCP and showed that improved Q 0 in the medium field in both fine-grain and large-grain cavities is possible with BCP postprocessing. However, there are differences between performances of large-grain versus fine-grain cavities after BCP. A cavity made from large-grain Nb showed a larger increase in Q 0 and a lower quench field compared to cavities made from fine-grain Nb.

show abstract

Section: Discussionmentioning

confidence: 91%

Surface characterization of nitrogen-doped high purity niobium coupons compared with superconducting rf cavity performance

Dhakal

Ciovati

Pudasaini

et al. 2019

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

show abstract

“…As described in [5,20], the two cavity vendors, RI Research Instruments GmbH (RI) and Ettore Zanon S.p.A. (EZ), were qualified to produce cavities after two distinct procedures. Most notably is the electron beam welding (EBW) procedure as well as the final surface chemistry step since both have a significant influence on the final surface and therefore RF performance.…”

Section: Vendor Dependent Surface Propertiesmentioning

confidence: 99%

Optical surface properties and their RF limitations of European XFEL cavities

Wenskat

2017

Supercond. Sci. Technol.

View full text Add to dashboard Cite

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. The industrial fabrication of cavities for the European X-Ray Free Electron Laser (XFEL) and the International Linear Collider (ILC) HiGrade Research Project allowed for an investigation of this interplay. For the serial inspection of the inner surface, the optical inspection robot OBACHT was constructed and to analyze the large amount of data, represented in the images of the inner surface, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. This quantitative analysis identified vendor specific surface properties which allow to perform a quality control and assurance during the production. In addition, a strong negative correlation of ρ = −0.93 with a significance of 6 σ of the integrated grain boundary area A versus the maximal achievable accelerating field E acc,max has been found.

show abstract

“…As described in [51,55], the two cavity vendors, RI Research Instruments GmbH (RI) and Ettore Zanon S.p.A. (EZ), were qualified to produce cavities after two distinct procedures. Most notably is the electron beam welding (EBW) procedure as well as the final surface chemistry step since both have a significant influence on the final surface and therefore onto the RF performance.…”

Section: Vendor Identificationmentioning

confidence: 99%

Automated optical inspection and image analysis of superconducting radio-frequency cavities

Wenskat

2017

J. Inst.

View full text Add to dashboard Cite

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. For an investigation of this inner surface of more than 100 cavities within the cavity fabrication for the European XFEL and the ILC HiGrade Research Project, an optical inspection robot OBACHT was constructed. To analyze up to 2325 images per cavity, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. The accuracy of this code is up to 97 % and the PPV 99 % within the resolution of 15.63 µm. The optical obtained surface roughness is in agreement with standard profilometric methods. The image analysis algorithm identified and quantified vendor specific fabrication properties as the electron beam welding speed and the different surface roughness due to the different chemical treatments. In addition, a correlation of ρ = −0.93 with a significance of 6 σ between an obtained surface variable and the maximal accelerating field was found.

show abstract

Production of superconducting 1.3-GHz cavities for the European X-ray Free Electron Laser

Cited by 38 publications

References 8 publications

Surface characterization of nitrogen-doped high purity niobium coupons compared with superconducting rf cavity performance

Surface characterization of nitrogen-doped high purity niobium coupons compared with superconducting rf cavity performance

Optical surface properties and their RF limitations of European XFEL cavities

Automated optical inspection and image analysis of superconducting radio-frequency cavities

Contact Info

Product

Resources

About