SRF2017 - List of Authors (Mikkola, T.)

Paper	Title	Page
TUPB016	Redesign of CERN's Quadrupole Resonator for Testing of Superconducting Samples	420
	V. del Pozo Romano, R. Betemps, F. Gerigk, R. Illan Fiastre, T. Mikkola CERN, Geneva, Switzerland
	The Quadrupole Resonator (QPR) was constructed in 1997 to measure the surface resistance of niobium samples at 400 MHz, the technology and RF frequency chosen for the LHC. It allows measurement of the RF properties of superconducting films deposited on disk-shaped metallic substrates. The samples are used to study different coatings which is much faster than the coating, stripping and re-coating of sample cavities. An electromagnetic and mechanical re-design of the existing QPR has been done with the goal of doubling the magnetic peak fields on the samples. Electromagnetic simulations were carried out on a completely parameterized model, using the actual CERN's QPR as baseline and modifying its dimensions. The aim was to optimize the measurement range and resolution by increasing the ratio between the magnetic peak fields on the sample and in the cavity. Increasing the average magnetic field on the sample leads to a more homogenous field distribution over the sample, which in turn gives a better resolution. Some of the modifications were based on the work already done by Helmholtz-Zentrum-Berlin for their upgraded version of the QPR.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB016
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WEYA03	A Seamless Quarter-wave Resonator for HIE-ISOLDE	686
	S. Teixeira Lopez, M.A. Fraser, M. Garlaschè, T. Mikkola, A. Miyazaki, A. Sublet, W. Venturini Delsolaro CERN, Geneva, Switzerland
	The superconducting linac booster for the HIE ISOLDE project, in operation at CERN, is based on NB/Cu coated Quarter Wave Resonators. The performance of the series cavities has been limited by defects in the copper substrates close to the EB weld. A novel cavity design has been developed and prototyped, in order to make it possible manufacturing of the resonators by machining them from the bulk, without any weld. The RF design was optimized for the customary figures of merit, and fully integrated in the HIE ISOLDE cryomodule. Mechanical tolerances were assessed in relation to the available range of pre tuning, and demonstrated on a dummy prototype. Beam dynamics simulations were carried out to check the effects on the beams when the new cavities will be installed in the high energy end of the linac. The presentation will cover the design and the first experimental results of the first Nb/Cu seamless QWR for HIE ISOLDE.
	Slides WEYA03 [5.262 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-WEYA03
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Redesign of CERN's Quadrupole Resonator for Testing of Superconducting Samples

420

V. del Pozo Romano, R. Betemps, F. Gerigk, R. Illan Fiastre, T. Mikkola
CERN, Geneva, Switzerland

The Quadrupole Resonator (QPR) was constructed in 1997 to measure the surface resistance of niobium samples at 400 MHz, the technology and RF frequency chosen for the LHC. It allows measurement of the RF properties of superconducting films deposited on disk-shaped metallic substrates. The samples are used to study different coatings which is much faster than the coating, stripping and re-coating of sample cavities. An electromagnetic and mechanical re-design of the existing QPR has been done with the goal of doubling the magnetic peak fields on the samples. Electromagnetic simulations were carried out on a completely parameterized model, using the actual CERN's QPR as baseline and modifying its dimensions. The aim was to optimize the measurement range and resolution by increasing the ratio between the magnetic peak fields on the sample and in the cavity. Increasing the average magnetic field on the sample leads to a more homogenous field distribution over the sample, which in turn gives a better resolution. Some of the modifications were based on the work already done by Helmholtz-Zentrum-Berlin for their upgraded version of the QPR.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-TUPB016

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEYA03

A Seamless Quarter-wave Resonator for HIE-ISOLDE

686

S. Teixeira Lopez, M.A. Fraser, M. Garlaschè, T. Mikkola, A. Miyazaki, A. Sublet, W. Venturini Delsolaro
CERN, Geneva, Switzerland

The superconducting linac booster for the HIE ISOLDE project, in operation at CERN, is based on NB/Cu coated Quarter Wave Resonators. The performance of the series cavities has been limited by defects in the copper substrates close to the EB weld. A novel cavity design has been developed and prototyped, in order to make it possible manufacturing of the resonators by machining them from the bulk, without any weld. The RF design was optimized for the customary figures of merit, and fully integrated in the HIE ISOLDE cryomodule. Mechanical tolerances were assessed in relation to the available range of pre tuning, and demonstrated on a dummy prototype. Beam dynamics simulations were carried out to check the effects on the beams when the new cavities will be installed in the high energy end of the linac. The presentation will cover the design and the first experimental results of the first Nb/Cu seamless QWR for HIE ISOLDE.

Slides WEYA03 [5.262 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2017-WEYA03

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)