SRF2023 - List of Authors (Marhauser, F.)

Paper	Title	Page
THIXA04	Development of a Prototype Superconducting Radio-Frequency Cavity for Conduction-Cooled Accelerators
	G. Ciovati, S. Balachandran, G. Cheng, E.F. Daly, P. Dhakal, K.A. Harding, F. Marhauser, T. Powers, U. Pudasaini, R.A. Rimmer, H. Vennekate JLab, Newport News, VA, USA J.P. Anderson, B.R.L. Coriton, L.D. Holland, K.R. McLaughlin, D.A. Packard, D.M. Vollmer GA, San Diego, California, USA A.V. Gurevich ODU, Norfolk, Virginia, USA J. Rathke TechSource, Los Alamos, New Mexico, USA T. Schultheiss TJS Technologies, Commack, New York, USA
	Funding: Work supported by the U.S. DOE, ARDAP Office, under contract No. DE-AC05-06OR23177. SB¿s microscopy work at the NHMFL was partly supported by the U.S. DOE, HEP Office under Award No. DE-SC0009960. Recent progress in the development of high-quality Nb₃Sn film coatings along with the availability of cryocoolers with high cooling capacity at 4 K makes it feasible to operate SRF cavities cooled by thermal conduction at relevant accelerating gradients for use in accelerators. We have developed a prototype single-cell cavity to prove the feasibility of operation up to the accelerating gradient required for 1 MeV energy gain, cooled by conduction with cryocoolers. The cavity has a ~3 ¿m thick Nb₃Sn film on the inner surface, deposited on a ~4 mm thick bulk Nb substrate and a bulk ~7 mm thick Cu outer shell with three Cu attachment tabs. The cavity was tested up to a peak surface magnetic field of 53 mT in liquid He at 4.3 K. A horizontal test cryostat was designed and built to test the cavity cooled with three cryocoolers. The rf tests of the conduction-cooled cavity achieved a peak surface magnetic field of 50 mT and stable operation was possible with up to 18.5 W of rf heat load. The peak frequency shift due to microphonics was 23 Hz. These results represent the highest peak surface magnetic field achieved in a conduction-cooled SRF cavity to date
	Slides THIXA04 [3.906 MB]
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TUPTB067	Fabrication and Surface Treatment of Superconducting Rf Single Spoke Cavities for the Myrrha Project	578
	M. Moretti, Y.N. Hoerstensmeyer, A. Navitski RI Research Instruments GmbH, Bergisch Gladbach, Germany F. Marhauser SCK•CEN, Mol, Belgium
	The MYRRHA project, based at SCK•CEN (Belgium), aims at coupling a 600 MeV proton accelerator to a subcritical fission core with a maximal output of 100 MWth. The first phase of the project, MINERVA, includes the design, construction, and commissioning of a 100 MeV superconducting RF linac in order to demonstrate the machine requirements in terms of reliability and fault tolerance. The MINERVA linac comprises several cryomodules, each containing two Single Spoke 352.2 MHz cavities made out of high RRR niobium and operating at 2K. The fabrication and surface treatment of the Single Spoke RF Cavities is currently ongoing and completely carried out by RI Research Instruments GmbH (Germany); the first pre-series cavities were completed and delivered for cold testing. Main highlights of the fabrication include the deep-drawing of complex shapes, such as central spokes and outer caps of the cavity, which was successfully accomplished. As for the surface treatment, RI has commissioned, tested, and effectively started utilizing a new rotational buffered chemical polishing facility; this is required to polish the cavity inner surface, while ensuring an almost uniform material removal.
DOI •	reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB067
About •	Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 09 July 2023
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Paper

Title

Page

THIXA04

Development of a Prototype Superconducting Radio-Frequency Cavity for Conduction-Cooled Accelerators

G. Ciovati, S. Balachandran, G. Cheng, E.F. Daly, P. Dhakal, K.A. Harding, F. Marhauser, T. Powers, U. Pudasaini, R.A. Rimmer, H. Vennekate
JLab, Newport News, VA, USA
J.P. Anderson, B.R.L. Coriton, L.D. Holland, K.R. McLaughlin, D.A. Packard, D.M. Vollmer
GA, San Diego, California, USA
A.V. Gurevich
ODU, Norfolk, Virginia, USA
J. Rathke
TechSource, Los Alamos, New Mexico, USA
T. Schultheiss
TJS Technologies, Commack, New York, USA

Funding: Work supported by the U.S. DOE, ARDAP Office, under contract No. DE-AC05-06OR23177. SB¿s microscopy work at the NHMFL was partly supported by the U.S. DOE, HEP Office under Award No. DE-SC0009960.
Recent progress in the development of high-quality Nb₃Sn film coatings along with the availability of cryocoolers with high cooling capacity at 4 K makes it feasible to operate SRF cavities cooled by thermal conduction at relevant accelerating gradients for use in accelerators. We have developed a prototype single-cell cavity to prove the feasibility of operation up to the accelerating gradient required for 1 MeV energy gain, cooled by conduction with cryocoolers. The cavity has a ~3 ¿m thick Nb₃Sn film on the inner surface, deposited on a ~4 mm thick bulk Nb substrate and a bulk ~7 mm thick Cu outer shell with three Cu attachment tabs. The cavity was tested up to a peak surface magnetic field of 53 mT in liquid He at 4.3 K. A horizontal test cryostat was designed and built to test the cavity cooled with three cryocoolers. The rf tests of the conduction-cooled cavity achieved a peak surface magnetic field of 50 mT and stable operation was possible with up to 18.5 W of rf heat load. The peak frequency shift due to microphonics was 23 Hz. These results represent the highest peak surface magnetic field achieved in a conduction-cooled SRF cavity to date

Slides THIXA04 [3.906 MB]

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TUPTB067

Fabrication and Surface Treatment of Superconducting Rf Single Spoke Cavities for the Myrrha Project

578

M. Moretti, Y.N. Hoerstensmeyer, A. Navitski
RI Research Instruments GmbH, Bergisch Gladbach, Germany
F. Marhauser
SCK•CEN, Mol, Belgium

The MYRRHA project, based at SCK•CEN (Belgium), aims at coupling a 600 MeV proton accelerator to a subcritical fission core with a maximal output of 100 MWth. The first phase of the project, MINERVA, includes the design, construction, and commissioning of a 100 MeV superconducting RF linac in order to demonstrate the machine requirements in terms of reliability and fault tolerance. The MINERVA linac comprises several cryomodules, each containing two Single Spoke 352.2 MHz cavities made out of high RRR niobium and operating at 2K. The fabrication and surface treatment of the Single Spoke RF Cavities is currently ongoing and completely carried out by RI Research Instruments GmbH (Germany); the first pre-series cavities were completed and delivered for cold testing. Main highlights of the fabrication include the deep-drawing of complex shapes, such as central spokes and outer caps of the cavity, which was successfully accomplished. As for the surface treatment, RI has commissioned, tested, and effectively started utilizing a new rotational buffered chemical polishing facility; this is required to polish the cavity inner surface, while ensuring an almost uniform material removal.

DOI •

reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB067

About •

Received ※ 17 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 09 July 2023

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