SRF2011 - List of Authors (Poupeau, J.P.)

Paper

Title

Page

High Power Pulsed Tests of a β=0.5 5-Cell 704 MHz Superconducting Cavity

345

J. Plouin, D. Braud, M. Desmons, G. Devanz, Y. Gasser, E. Jacques, O. Piquet, J.P. Poupeau, D. Roudier, P. Sahuquet
CEA/DSM/IRFU, France
W. Höfle, D. Valuch
CERN, Geneva, Switzerland

A β=0.5 5-cell 704 MHz cavity was developed in the framework of european R&D programs on high intensity pulsed proton injectors. Medium beta elliptical cavities are known to be sensitive to Lorentz detuning, which can become difficult to deal with in pulsed operation. The cavity was optimized to reduce the Lorentz detuning by means of two series of rings welded around the irises, and equipped with a piezo tuning system . In order to test the cavity in pulsed mode, a power coupler with 1 MW capability was connected to the cavity. We report here on the fully equipped cavity tests at 1.8 K carried out in the horizontal cryostat Cryholab at Saclay to study its Rf and mechanical behavior in pulsed mode, mostly with 2 ms pulses at a 50 Hz repetition rate. The compensation of Lorentz force detuning has been achieved at an accelerating gradient of 13 MV/m (44 MV/m peak surface electric field).

Poster TUPO002 [1.917 MB]

TUPO062

Vertical Electro-Polishing at CEA Saclay: Commissioning of a New Set-Up and Modeling of the Process Applied to Different Cavities

549

F. Eozénou, S. Chel, Y. Gasser, J.P. Poupeau, C. Servouin, Z. Wang
CEA/DSM/IRFU, France

Funding: We acknowledge the support of the EuCARD, ILC HiGrade and ASTRE programs.
High performance required for elliptical low beta cavity makes the electro-polishing desirable for their surface treatment. For large dimension cavities, the EP treatment in vertical configuration (abbreviated as VEP) is more appropriate. A VEP set-up has been designed at Saclay for the electro-polishing of such cavities. The electrolyte will be circulating and the process automated, including several safety procedures. Chosen equipment will make it possible to use a wide range of parameters (voltage, flowrate, temperature, nitrogen inerting) with R&D purpose in mind. R&D will guide the choice of adapted parameters in such configuration. In addition, VEP has been modeled using COMSOL software with 2D axi - symmetry configuration for 2 different cavities: - 9Cell ILC cavity - Proton 5Cell cavity for SPL accelerator. Different cathodes have been designed to optimize the fluid and the electric field distribution during VEP. Respective results will be presented. At last, importance of the size of the cavity will be commented.

Poster TUPO062 [2.067 MB]

Paper	Title	Page
TUPO002	High Power Pulsed Tests of a β=0.5 5-Cell 704 MHz Superconducting Cavity	345
	J. Plouin, D. Braud, M. Desmons, G. Devanz, Y. Gasser, E. Jacques, O. Piquet, J.P. Poupeau, D. Roudier, P. Sahuquet CEA/DSM/IRFU, France W. Höfle, D. Valuch CERN, Geneva, Switzerland
	A β=0.5 5-cell 704 MHz cavity was developed in the framework of european R&D programs on high intensity pulsed proton injectors. Medium beta elliptical cavities are known to be sensitive to Lorentz detuning, which can become difficult to deal with in pulsed operation. The cavity was optimized to reduce the Lorentz detuning by means of two series of rings welded around the irises, and equipped with a piezo tuning system . In order to test the cavity in pulsed mode, a power coupler with 1 MW capability was connected to the cavity. We report here on the fully equipped cavity tests at 1.8 K carried out in the horizontal cryostat Cryholab at Saclay to study its Rf and mechanical behavior in pulsed mode, mostly with 2 ms pulses at a 50 Hz repetition rate. The compensation of Lorentz force detuning has been achieved at an accelerating gradient of 13 MV/m (44 MV/m peak surface electric field).
	Poster TUPO002 [1.917 MB]

TUPO062	Vertical Electro-Polishing at CEA Saclay: Commissioning of a New Set-Up and Modeling of the Process Applied to Different Cavities	549
	F. Eozénou, S. Chel, Y. Gasser, J.P. Poupeau, C. Servouin, Z. Wang CEA/DSM/IRFU, France
	Funding: We acknowledge the support of the EuCARD, ILC HiGrade and ASTRE programs. High performance required for elliptical low beta cavity makes the electro-polishing desirable for their surface treatment. For large dimension cavities, the EP treatment in vertical configuration (abbreviated as VEP) is more appropriate. A VEP set-up has been designed at Saclay for the electro-polishing of such cavities. The electrolyte will be circulating and the process automated, including several safety procedures. Chosen equipment will make it possible to use a wide range of parameters (voltage, flowrate, temperature, nitrogen inerting) with R&D purpose in mind. R&D will guide the choice of adapted parameters in such configuration. In addition, VEP has been modeled using COMSOL software with 2D axi - symmetry configuration for 2 different cavities: - 9Cell ILC cavity - Proton 5Cell cavity for SPL accelerator. Different cathodes have been designed to optimize the fluid and the electric field distribution during VEP. Respective results will be presented. At last, importance of the size of the cavity will be commented.
	Poster TUPO062 [2.067 MB]