SRF2015 - List of Authors (Gerigk, F.)

Paper	Title	Page
MOPB078	Mode Sensitivity Analysis of 704.4 MHz Superconducting RF Cavities	311
	K. Papke, F. Gerigk, S. Horvath-Mikulas, S. Papadopoulos, E. Pilicer, F. Pillon CERN, Geneva, Switzerland U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Due to the large variety of beam patterns considered for the superconducting proton linac (SPL) at CERN it is likely that the frequencies of some HOMs are close to machine lines during operation. Hence, in the interest of developing a method to shift HOM frequencies away from machine lines, we study the influence of cavity detuning and re-tuning (e.g. by Lorentz forces, field flatness tuning, frequency tuning during operation) on HOMs. The sensitivity of HOMs with respect to the fundamental mode was studied for a mono-cell and for 5-cell high-beta SPL cavities operating at 704.4 MHz. First, the variation of the HOMs during the flat-field tuning was measured. In this process, several detuning and re-tuning cycles were made to estimate the range of possible HOM frequency shifts. Secondly the effect of the frequency tuner on the HOMs is presented and finally the frequency shifts of all modes due to the cool down.
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THAA05	First Results of SRF Cavity Fabrication by Electro-Hydraulic Forming at CERN	1012
	S. Atieh, A. Amorim Carvalho, I. Aviles Santillana, F.F. Bertinelli, R. Calaga, O. Capatina, G. Favre, M. Garlaschè, F. Gerigk, S.A.E. Langeslag, K.M. Schirm, N. Valverde Alonso CERN, Geneva, Switzerland D. Alleman, G. Avrillaud, J. Bonafe, E. Mandel, P. Marty, H. Peronnet, R. Plaut Bmax, Toulouse, France
	In the framework of many accelerator projects relying on RF superconducting technology, shape conformity and processing time are key aspects for the optimization of niobium cavity fabrication. An alternative technique to traditional shaping methods, such as deep-drawing and spinning, is Electro-Hydraulic Forming (EHF). In EHF, cavities are obtained through ultra-high-speed deformation of blank sheets, using shockwaves induced in water by a pulsed electrical discharge. With respect to traditional methods, such a highly dynamic process can yield valuable results in terms of effectiveness, repeatability, final shape precision, higher formability and reduced spring-back. In this paper, the first results of EHF on copper prototypes and ongoing developments for niobium for the Superconducting Proton Linac studies at CERN are discussed. The simulations performed in order to master the embedded multi-physics phenomena and to steer process parameters are also presented.
	Slides THAA05 [21.123 MB]
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Paper

Title

Page

Mode Sensitivity Analysis of 704.4 MHz Superconducting RF Cavities

311

K. Papke, F. Gerigk, S. Horvath-Mikulas, S. Papadopoulos, E. Pilicer, F. Pillon
CERN, Geneva, Switzerland
U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Due to the large variety of beam patterns considered for the superconducting proton linac (SPL) at CERN it is likely that the frequencies of some HOMs are close to machine lines during operation. Hence, in the interest of developing a method to shift HOM frequencies away from machine lines, we study the influence of cavity detuning and re-tuning (e.g. by Lorentz forces, field flatness tuning, frequency tuning during operation) on HOMs. The sensitivity of HOMs with respect to the fundamental mode was studied for a mono-cell and for 5-cell high-beta SPL cavities operating at 704.4 MHz. First, the variation of the HOMs during the flat-field tuning was measured. In this process, several detuning and re-tuning cycles were made to estimate the range of possible HOM frequency shifts. Secondly the effect of the frequency tuner on the HOMs is presented and finally the frequency shifts of all modes due to the cool down.

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)

THAA05

First Results of SRF Cavity Fabrication by Electro-Hydraulic Forming at CERN

1012

S. Atieh, A. Amorim Carvalho, I. Aviles Santillana, F.F. Bertinelli, R. Calaga, O. Capatina, G. Favre, M. Garlaschè, F. Gerigk, S.A.E. Langeslag, K.M. Schirm, N. Valverde Alonso
CERN, Geneva, Switzerland
D. Alleman, G. Avrillaud, J. Bonafe, E. Mandel, P. Marty, H. Peronnet, R. Plaut
Bmax, Toulouse, France

In the framework of many accelerator projects relying on RF superconducting technology, shape conformity and processing time are key aspects for the optimization of niobium cavity fabrication. An alternative technique to traditional shaping methods, such as deep-drawing and spinning, is Electro-Hydraulic Forming (EHF). In EHF, cavities are obtained through ultra-high-speed deformation of blank sheets, using shockwaves induced in water by a pulsed electrical discharge. With respect to traditional methods, such a highly dynamic process can yield valuable results in terms of effectiveness, repeatability, final shape precision, higher formability and reduced spring-back. In this paper, the first results of EHF on copper prototypes and ongoing developments for niobium for the Superconducting Proton Linac studies at CERN are discussed. The simulations performed in order to master the embedded multi-physics phenomena and to steer process parameters are also presented.

Slides THAA05 [21.123 MB]

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reference for this paper to ※ BibTeX, ※ LaTeX, ※ Text, ※ RIS/RefMan, ※ EndNote (xml)