SRF2013 - List of Authors (Olry, G.)

Paper

Title

Page

Status and Challenges of Spiral2 SRF Linac

11

R. Ferdinand, P.-E. Bernaudin, M. Di Giacomo
GANIL, Caen, France
P. Bosland
CEA/IRFU, Gif-sur-Yvette, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France
G. Olry
IPN, Orsay, France

GANIL is presently extending its experimental facility with the new SPIRAL2 project. It is based on a multi-beam Superconducting Linac Driver delivering 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. Several domains of research in nuclear physics at the limits of stability will be covered by this new accelerator. SPIRAL2 construction has two phases. SPIRAL2 phase 1 includes the superconducting accelerator driver, and the construction of the two research areas where the accelerated protons and deuterons will generate extremely intense neutron beams for fundamental physics experiments and numerous applications. SPIRAL2 will also accelerate stable heavy ion beams of very high intensity. The phase2 includes the RIB production building and links to the existing GANIL accelerator complex for RIB post acceleration. The Superconducting Linac incorporates many innovative developments of the Quarter-Wave resonators and their associated cryogenic and RF systems. The installation of the SPIRAL2 accelerator at GANIL has started. Status of the Spiral 2 SRF linac will be presented, focusing on the various SRF challenges met by this project and how/what solutions were chosen.
* on behalf of the SPIRAL2 project and superconducting teams

Slides MOIOA02 [87.841 MB]

MOP010

Spiral2 Cryomodules B Tests Results

95

G. Olry, F. Chatelet, C. Commeaux, N. Gandolfo, D. Grolet, C. Joly, J. Lesrel, D. Longuevergne, R. Martret, G. Michel, L. Renard, A. Stephen, P. Szott
IPN, Orsay, France
P.-E. Bernaudin, R. Beunard, R. Ferdinand, A. Lefevre
GANIL, Caen, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France

Assembly and tests of the SPIRAL2 superconducting linac's cryomodules at CEA/Saclay and IPN/Orsay have now reached cruising speed after having faced a series of problems, among them contamination. 19 cryomodules are composing the whole Linac and IPN Orsay is in charge of the 7 cryomodules B, housing two 88MHz, beta 0.12 Quarter-Wave Resonators. Two cryomodules have been successfully assembled and tested up to the nominal gradient of 6.5 MV/m for all cavities with also total cryogenic losses under specifications. One of them is fully qualified and has been already delivered to GANIL. The second one showed misalignment on one cavity which could lead to partial disassembly. This paper will present the results of those cryomodules tests as well as the status of the remaining ones.

MOP075

A X-rays Shielded Facility Dedicated to Cryogenic RF Tests of Fully Dressed Spoke Cavities in the Cryomodule CM0 at IPN Orsay

M. Fouaidy, P. Duchesne, N. Gandolfo, D. Grolet, C. Joly, G. Olry, M. Pierens, V. Poux, D. Reynet
IPN, Orsay, France
C.C. Motta
USP, São Paulo, Brazil

A bulk Nb superconducting β=0.3 Triple-Spoke (T-Spoke) cavity operating at 352 MHz, was designed at IPN and fabricated thanks to EURISOL project financial support. The cavity will be tested in November 2013 at a new X-rays shielded facility dedicated to cryogenic tests of fully dressed (LHe tank, Magnetic Shields, Fast Active Cold Piezoelectric Tuning System (FACPTS), RF Power coupler) Spoke cavities in the horizontal cryomodule CM0. The CW RF power and cryogenic power @T=2K are 80kW and 120W respectively. Four vertical cold RF tests were performed in a vertical cryostat and the data are reported. All components (cold box, cryogenic lines, He gas heater, RF power system with 2 RF power couplers, LHe bath pumps) were delivered and successfully tested. The cryogenic circuit in CM0 was finished and we successfully mounted the fully dressed T-Spoke cavity. A R.T tuning system was used for static and dynamic mechanical measurements on Single (S-Spoke) and T-Spoke cavities. Mechanical stiffness, transfer function, vibrations, Lorentz detuning were investigated using the FACPTS. Field profile in S-Spoke and T-Spoke cavities were performed using a motorized field perturbation stand.

MOP089

Design of the ESS Spoke Cryomodule

357

D. Reynet, S. Bousson, S. Brault, P. Duchesne, P. Duthil, N. Gandolfo, G. Olry, E. Rampnoux
IPN, Orsay, France

The European Spallation Source (ESS) project brings together 17 European countries to develop the world’s most powerful neutron source feeding multidisplinary researches. The superconducting part of the linear accelerator consists in 59 cryomodules housing different superconducting radiofrequency (SRF) resonators among which 28 paired β=0.5 352.2 MHz SRF niobium double Spoke cavities, held at 2K in a saturated helium bath. A prototype Spoke cryomodule with two cavities equipped with their 300kW RF power couplers is now being designed and will be constructed and tested at full power by the end of 2015 for the validation of all chosen technical solutions. It integrates all the interfaces necessary to be operational within a linac machine. Its assembly requires dedicated tooling and procedures in and out of a clean room. The design takes into account an industrial approach for the management of the fabrication costs. This prototype will have to guarantee an accelerating field of 8MV/m while optimizing the energy consumption and will aim at assessing the maintenance operations issues. We propose to present the design of this cryomodule and its related tooling.

THIOD04

A Cold Tuner System With Mobile Plunger

884

D. Longuevergne, S. Blivet, S. Bousson, N. Gandolfo, G. Martinet, G. Olry, H. Saugnac
IPN, Orsay, France

Tuner systems for accelerating cavities are required to compensate static and dynamic frequency perturbations during beam operation. In the case of superconducting cavities, these are commonly tuned by deforming the cavity wall in specific places of the geometry. Nevertheless, considering the mechanical properties and frequency versus displacement sensitivity of some structures, tuning by deformation doesn’t allow to meet the requirements. In these specific cases, inspired from the “room temperature technology”, an alternative tuning technique by insertion of a helium-cooled superconducting plunger can be considered and has been studied for several projects (IFMIF, ESS-BILBAO). Advantages and drawbacks of such solution will be discussed and the successful results on SPIRAL2 cryomodule developed at IPNO will be presented.

Slides THIOD04 [4.938 MB]

THP018

Design of a Superconducting 352MHz Fully Jacketed Double-Spoke Resonator for the ESS-Bilbao Proton Linac

929

T. Junquera
Accelerators and Cryogenic Systems, Orsay, France
F.J. Bermejo, J.L. Muñoz, A. Vélez
ESS Bilbao, Bilbao, Spain
P. Duchesne, G. Olry
IPN, Orsay, France

The baseline design for the ESS-Bilbao light-ion linear accelerator and neutron source (a facility compliant with the ESS-AB requirements) has been completed and the normal conducting section of the linac (RFQ and DTL) is at present under detailed design and construction. Starting at 50 MeV, it is proposed to follow this section with a superconducting section composed of double and triple spoke cavities grouped in cryomodules of 2 or 3 cavities reaching a maximum energy of 300 MeV. After an initial R&D program on spoke cavities with an aluminum model, detailed electromagnetic and mechanical studies of a beta 0.50, 352MHz, double spoke cavity were performed. The results of the calculations are presented in this paper. It is proposed to continue this development by the construction and test of the niobium cavities prototypes and initiating the study of a cryo-module with two cavities that could be tested with beam at the ESS-Bilbao facility.

THP065

Design of 352.21 MHz RF Power Input Coupler and Window for the European Spallation Source Project (ESS)

1069

E. Rampnoux, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet
IPN, Orsay, France

A 352.21 MHz RF high power coupler window was designed by IPNO to meet the specification requirements for the ESS accelerator project. This designed is based on IPNO’s power coupler developments performed in the framework of the EURISOL Design Study project for which two power couplers using coaxial technology without chokes systems around the ceramic disc have been designed and tested successfully up to 20 kW RF power level in CW mode. For ESS project, the RF power input window was developed and designed to reliability operate at an average power level of 25 kW up to 300 kW in pulsed and continuous wave modes. This 352.21 MHz RF window was developed to remove the chocks usually used and provided the following advantages: more reliability, less expensive to manufacture, better vacuum, easier cleaning, less secondary electron-multipacting with specificity to present a bandwidth close to 1 GHz.

THP078

Deformation Tuner Design for a Double Spoke Cavity

1104

N. Gandolfo, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet
IPN, Orsay, France

IPN Orsay is developing the low-beta double Spoke cavities cryomodule for the ESS. Based on previous successfully tested prototypes, a fast/slow tuner has been studied to compensate resonance frequency variations of the cavity during operation. The typical perturbations are coming from LHe pressure variations as well as microphonics and Lorentz force detuning (LFD). Two tuners are being built in order to validate both expected performances and series production feasibility. In this paper, the tuner design of the double Spoke cavity is presented.

FRIOC01

Design of the 352 MHz, Beta 0.50, Double-Spoke Cavity for ESS

1212

P. Duchesne, S. Bousson, S. Brault, P. Duthil, G. Olry, D. Reynet
IPN, Orsay, France
S. Molloy
ESS, Lund, Sweden

The ESS proton accelerator contains a superconducting sector consisting in three families of superconducting radiofrequency (SRF) bulk niobium cavities, operating at a nominal temperature of 2K: a family of Spoke cavities for the medium energy section followed by two families of elliptical cavities for higher energies. The superconducting Spoke section, having a length of 58.6m, consists of 14 cryomodules, each of them housing two 352.2 MHz β=0.50 Double-Spoke Resonators (DSR). The operating accelerating field is 8MV/m. The choice of the Spoke technology is guided by the high performances of such structures. Benefitting from 10 years of extensive R&D experience carried out at IPNO, the electromagnetic design studies came out with a solution that fulfills requirements of beam dynamics analysis and manufacturing considerations. Pursuing the same objective, the mechanical design of the cavity and its helium vessel were optimized by performing intensive coupled RF-mechanical simulations. We propose to present a review of the RF and mechanical design studies of the Spoke cavity. We will conclude with the integration of the Spoke cavity with its ancillaries inside the cryomodule.

Slides FRIOC01 [6.321 MB]

Paper	Title	Page
MOIOA02	Status and Challenges of Spiral2 SRF Linac	11
	R. Ferdinand, P.-E. Bernaudin, M. Di Giacomo GANIL, Caen, France P. Bosland CEA/IRFU, Gif-sur-Yvette, France Y. Gómez Martínez LPSC, Grenoble Cedex, France G. Olry IPN, Orsay, France
	GANIL is presently extending its experimental facility with the new SPIRAL2 project. It is based on a multi-beam Superconducting Linac Driver delivering 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. Several domains of research in nuclear physics at the limits of stability will be covered by this new accelerator. SPIRAL2 construction has two phases. SPIRAL2 phase 1 includes the superconducting accelerator driver, and the construction of the two research areas where the accelerated protons and deuterons will generate extremely intense neutron beams for fundamental physics experiments and numerous applications. SPIRAL2 will also accelerate stable heavy ion beams of very high intensity. The phase2 includes the RIB production building and links to the existing GANIL accelerator complex for RIB post acceleration. The Superconducting Linac incorporates many innovative developments of the Quarter-Wave resonators and their associated cryogenic and RF systems. The installation of the SPIRAL2 accelerator at GANIL has started. Status of the Spiral 2 SRF linac will be presented, focusing on the various SRF challenges met by this project and how/what solutions were chosen. * on behalf of the SPIRAL2 project and superconducting teams
	Slides MOIOA02 [87.841 MB]

MOP010	Spiral2 Cryomodules B Tests Results	95
	G. Olry, F. Chatelet, C. Commeaux, N. Gandolfo, D. Grolet, C. Joly, J. Lesrel, D. Longuevergne, R. Martret, G. Michel, L. Renard, A. Stephen, P. Szott IPN, Orsay, France P.-E. Bernaudin, R. Beunard, R. Ferdinand, A. Lefevre GANIL, Caen, France Y. Gómez Martínez LPSC, Grenoble Cedex, France
	Assembly and tests of the SPIRAL2 superconducting linac's cryomodules at CEA/Saclay and IPN/Orsay have now reached cruising speed after having faced a series of problems, among them contamination. 19 cryomodules are composing the whole Linac and IPN Orsay is in charge of the 7 cryomodules B, housing two 88MHz, beta 0.12 Quarter-Wave Resonators. Two cryomodules have been successfully assembled and tested up to the nominal gradient of 6.5 MV/m for all cavities with also total cryogenic losses under specifications. One of them is fully qualified and has been already delivered to GANIL. The second one showed misalignment on one cavity which could lead to partial disassembly. This paper will present the results of those cryomodules tests as well as the status of the remaining ones.

MOP075	A X-rays Shielded Facility Dedicated to Cryogenic RF Tests of Fully Dressed Spoke Cavities in the Cryomodule CM0 at IPN Orsay
	M. Fouaidy, P. Duchesne, N. Gandolfo, D. Grolet, C. Joly, G. Olry, M. Pierens, V. Poux, D. Reynet IPN, Orsay, France C.C. Motta USP, São Paulo, Brazil
	A bulk Nb superconducting β=0.3 Triple-Spoke (T-Spoke) cavity operating at 352 MHz, was designed at IPN and fabricated thanks to EURISOL project financial support. The cavity will be tested in November 2013 at a new X-rays shielded facility dedicated to cryogenic tests of fully dressed (LHe tank, Magnetic Shields, Fast Active Cold Piezoelectric Tuning System (FACPTS), RF Power coupler) Spoke cavities in the horizontal cryomodule CM0. The CW RF power and cryogenic power @T=2K are 80kW and 120W respectively. Four vertical cold RF tests were performed in a vertical cryostat and the data are reported. All components (cold box, cryogenic lines, He gas heater, RF power system with 2 RF power couplers, LHe bath pumps) were delivered and successfully tested. The cryogenic circuit in CM0 was finished and we successfully mounted the fully dressed T-Spoke cavity. A R.T tuning system was used for static and dynamic mechanical measurements on Single (S-Spoke) and T-Spoke cavities. Mechanical stiffness, transfer function, vibrations, Lorentz detuning were investigated using the FACPTS. Field profile in S-Spoke and T-Spoke cavities were performed using a motorized field perturbation stand.

MOP089	Design of the ESS Spoke Cryomodule	357
	D. Reynet, S. Bousson, S. Brault, P. Duchesne, P. Duthil, N. Gandolfo, G. Olry, E. Rampnoux IPN, Orsay, France
	The European Spallation Source (ESS) project brings together 17 European countries to develop the world’s most powerful neutron source feeding multidisplinary researches. The superconducting part of the linear accelerator consists in 59 cryomodules housing different superconducting radiofrequency (SRF) resonators among which 28 paired β=0.5 352.2 MHz SRF niobium double Spoke cavities, held at 2K in a saturated helium bath. A prototype Spoke cryomodule with two cavities equipped with their 300kW RF power couplers is now being designed and will be constructed and tested at full power by the end of 2015 for the validation of all chosen technical solutions. It integrates all the interfaces necessary to be operational within a linac machine. Its assembly requires dedicated tooling and procedures in and out of a clean room. The design takes into account an industrial approach for the management of the fabrication costs. This prototype will have to guarantee an accelerating field of 8MV/m while optimizing the energy consumption and will aim at assessing the maintenance operations issues. We propose to present the design of this cryomodule and its related tooling.

THIOD04	A Cold Tuner System With Mobile Plunger	884
	D. Longuevergne, S. Blivet, S. Bousson, N. Gandolfo, G. Martinet, G. Olry, H. Saugnac IPN, Orsay, France
	Tuner systems for accelerating cavities are required to compensate static and dynamic frequency perturbations during beam operation. In the case of superconducting cavities, these are commonly tuned by deforming the cavity wall in specific places of the geometry. Nevertheless, considering the mechanical properties and frequency versus displacement sensitivity of some structures, tuning by deformation doesn’t allow to meet the requirements. In these specific cases, inspired from the “room temperature technology”, an alternative tuning technique by insertion of a helium-cooled superconducting plunger can be considered and has been studied for several projects (IFMIF, ESS-BILBAO). Advantages and drawbacks of such solution will be discussed and the successful results on SPIRAL2 cryomodule developed at IPNO will be presented.
	Slides THIOD04 [4.938 MB]

THP018	Design of a Superconducting 352MHz Fully Jacketed Double-Spoke Resonator for the ESS-Bilbao Proton Linac	929
	T. Junquera Accelerators and Cryogenic Systems, Orsay, France F.J. Bermejo, J.L. Muñoz, A. Vélez ESS Bilbao, Bilbao, Spain P. Duchesne, G. Olry IPN, Orsay, France
	The baseline design for the ESS-Bilbao light-ion linear accelerator and neutron source (a facility compliant with the ESS-AB requirements) has been completed and the normal conducting section of the linac (RFQ and DTL) is at present under detailed design and construction. Starting at 50 MeV, it is proposed to follow this section with a superconducting section composed of double and triple spoke cavities grouped in cryomodules of 2 or 3 cavities reaching a maximum energy of 300 MeV. After an initial R&D program on spoke cavities with an aluminum model, detailed electromagnetic and mechanical studies of a beta 0.50, 352MHz, double spoke cavity were performed. The results of the calculations are presented in this paper. It is proposed to continue this development by the construction and test of the niobium cavities prototypes and initiating the study of a cryo-module with two cavities that could be tested with beam at the ESS-Bilbao facility.

THP065	Design of 352.21 MHz RF Power Input Coupler and Window for the European Spallation Source Project (ESS)	1069
	E. Rampnoux, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet IPN, Orsay, France
	A 352.21 MHz RF high power coupler window was designed by IPNO to meet the specification requirements for the ESS accelerator project. This designed is based on IPNO’s power coupler developments performed in the framework of the EURISOL Design Study project for which two power couplers using coaxial technology without chokes systems around the ceramic disc have been designed and tested successfully up to 20 kW RF power level in CW mode. For ESS project, the RF power input window was developed and designed to reliability operate at an average power level of 25 kW up to 300 kW in pulsed and continuous wave modes. This 352.21 MHz RF window was developed to remove the chocks usually used and provided the following advantages: more reliability, less expensive to manufacture, better vacuum, easier cleaning, less secondary electron-multipacting with specificity to present a bandwidth close to 1 GHz.

THP078	Deformation Tuner Design for a Double Spoke Cavity	1104
	N. Gandolfo, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet IPN, Orsay, France
	IPN Orsay is developing the low-beta double Spoke cavities cryomodule for the ESS. Based on previous successfully tested prototypes, a fast/slow tuner has been studied to compensate resonance frequency variations of the cavity during operation. The typical perturbations are coming from LHe pressure variations as well as microphonics and Lorentz force detuning (LFD). Two tuners are being built in order to validate both expected performances and series production feasibility. In this paper, the tuner design of the double Spoke cavity is presented.

FRIOC01	Design of the 352 MHz, Beta 0.50, Double-Spoke Cavity for ESS	1212
	P. Duchesne, S. Bousson, S. Brault, P. Duthil, G. Olry, D. Reynet IPN, Orsay, France S. Molloy ESS, Lund, Sweden
	The ESS proton accelerator contains a superconducting sector consisting in three families of superconducting radiofrequency (SRF) bulk niobium cavities, operating at a nominal temperature of 2K: a family of Spoke cavities for the medium energy section followed by two families of elliptical cavities for higher energies. The superconducting Spoke section, having a length of 58.6m, consists of 14 cryomodules, each of them housing two 352.2 MHz β=0.50 Double-Spoke Resonators (DSR). The operating accelerating field is 8MV/m. The choice of the Spoke technology is guided by the high performances of such structures. Benefitting from 10 years of extensive R&D experience carried out at IPNO, the electromagnetic design studies came out with a solution that fulfills requirements of beam dynamics analysis and manufacturing considerations. Pursuing the same objective, the mechanical design of the cavity and its helium vessel were optimized by performing intensive coupled RF-mechanical simulations. We propose to present a review of the RF and mechanical design studies of the Spoke cavity. We will conclude with the integration of the Spoke cavity with its ancillaries inside the cryomodule.
	Slides FRIOC01 [6.321 MB]