IPAC2011 - List of Authors (Arnau-Izquierdo, G.)

Paper

Title

Page

Mechanical Design and Fabrication Studies for SPL Superconducting RF Cavities

199

S. Atieh, G. Arnau-Izquierdo, I. Aviles Santillana, O. Capatina, T. Renaglia, T. Tardy, N. Valverde Alonso, W. Weingarten
CERN, Geneva, Switzerland

CERN’s R&D programme on the Superconducting Proton Linac’s (SPL) superconducting radio frequency (SRF) elliptical cavities made from niobium sheets explores new mechanical design and consequently new fabrication methods, where several opportunities for improved optimization were identified. A stainless steel helium vessel is under design rather than a titanium helium vessel using an integrated brazed transition between Nb and the SS helium vessel. Different design and fabrication aspects were proposed and the results are discussed hereafter.

TUPS098

Machining and Characterizing X-band RF-structures for CLIC

1768

S. Atieh, M. Aicheler, G. Arnau-Izquierdo, A. Cherif, L. Deparis, D. Glaude, L. Remandet, G. Riddone, M. Scheubel
CERN, Geneva, Switzerland
D. Gudkov, A. Samoshkin, A. Solodko
JINR, Dubna, Moscow Region, Russia

The Compact Linear Collider (CLIC) is currently under study at CERN as a potential multi-TeV e+e collider. The manufacturing and assembling tolerances for making the required RF components are essential for CLIC to perform efficiently. Machining techniques are relevant to the construction of ultra-high-precision parts for the Accelerating Structures (AS). Optical-quality turning and ultra-precision milling using diamond tools are the main manufacturing techniques identified to produce ultra-high shape accuracy parts. A shape error of less than 5 micrometres and roughness of Ra 0.025 are achieved. Scanning Electron Microscopy (SEM) observation as well as sub-micron precision Coordinate Measuring Machines (CMM), roughness measurements and their crucial environment were implemented at CERN for quality assurance and further development. This paper focuses on the enhancements of precision machining and characterizing the fabrication of AS parts.

TUPS099

A Study of the Surface Quality of High Purity Copper after Heat Treatment

1771

M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin
CERN, Geneva, Switzerland

The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

THOBB03

Research and Development of Novel Advanced Materials for Next-generation Collimators

2888

A. Bertarelli, G. Arnau-Izquierdo, F. Carra, A. Dallocchio, M. Gil Costa, N. Mariani
CERN, Geneva, Switzerland

Funding: This work has partly been carried out through the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program.
The study of innovative collimators is essential to handle the high energy particle beams required to explore unknown territory in basic research. This calls for the development of novel advanced materials, as no existing metal-based or carbon-based material possesses the combination of physical, thermal, electrical and mechanical properties, imposed by collimator extreme working conditions. A new family of materials, with promising features, has been identified: metal-diamond composites. These materials are to combine the outstanding thermal and physical properties of diamond with the electrical and mechanical properties of metals. The best candidates are Copper-Diamond (Cu-CD) and Molybdenum-Diamond (Mo-CD). In particular, Mo-CD may provide interesting properties as to mechanical strength, melting temperature, thermal shock resistance and, thanks to its balanced material density, energy absorption. The research program carried out on these materials at CERN and collaborating partners is presented, mainly focusing on the theoretical investigation, material characterization, and manufacturing processes.

Slides THOBB03 [3.948 MB]

Paper	Title	Page
MOPC053	Mechanical Design and Fabrication Studies for SPL Superconducting RF Cavities	199
	S. Atieh, G. Arnau-Izquierdo, I. Aviles Santillana, O. Capatina, T. Renaglia, T. Tardy, N. Valverde Alonso, W. Weingarten CERN, Geneva, Switzerland
	CERN’s R&D programme on the Superconducting Proton Linac’s (SPL) superconducting radio frequency (SRF) elliptical cavities made from niobium sheets explores new mechanical design and consequently new fabrication methods, where several opportunities for improved optimization were identified. A stainless steel helium vessel is under design rather than a titanium helium vessel using an integrated brazed transition between Nb and the SS helium vessel. Different design and fabrication aspects were proposed and the results are discussed hereafter.

TUPS098	Machining and Characterizing X-band RF-structures for CLIC	1768
	S. Atieh, M. Aicheler, G. Arnau-Izquierdo, A. Cherif, L. Deparis, D. Glaude, L. Remandet, G. Riddone, M. Scheubel CERN, Geneva, Switzerland D. Gudkov, A. Samoshkin, A. Solodko JINR, Dubna, Moscow Region, Russia
	The Compact Linear Collider (CLIC) is currently under study at CERN as a potential multi-TeV e+e collider. The manufacturing and assembling tolerances for making the required RF components are essential for CLIC to perform efficiently. Machining techniques are relevant to the construction of ultra-high-precision parts for the Accelerating Structures (AS). Optical-quality turning and ultra-precision milling using diamond tools are the main manufacturing techniques identified to produce ultra-high shape accuracy parts. A shape error of less than 5 micrometres and roughness of Ra 0.025 are achieved. Scanning Electron Microscopy (SEM) observation as well as sub-micron precision Coordinate Measuring Machines (CMM), roughness measurements and their crucial environment were implemented at CERN for quality assurance and further development. This paper focuses on the enhancements of precision machining and characterizing the fabrication of AS parts.

TUPS099	A Study of the Surface Quality of High Purity Copper after Heat Treatment	1771
	M. Aicheler, G. Arnau-Izquierdo, S. Atieh, S. Calatroni, S. Lebet, G. Riddone, A. Samoshkin CERN, Geneva, Switzerland
	The manufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

THOBB03	Research and Development of Novel Advanced Materials for Next-generation Collimators	2888
	A. Bertarelli, G. Arnau-Izquierdo, F. Carra, A. Dallocchio, M. Gil Costa, N. Mariani CERN, Geneva, Switzerland
	Funding: This work has partly been carried out through the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program. The study of innovative collimators is essential to handle the high energy particle beams required to explore unknown territory in basic research. This calls for the development of novel advanced materials, as no existing metal-based or carbon-based material possesses the combination of physical, thermal, electrical and mechanical properties, imposed by collimator extreme working conditions. A new family of materials, with promising features, has been identified: metal-diamond composites. These materials are to combine the outstanding thermal and physical properties of diamond with the electrical and mechanical properties of metals. The best candidates are Copper-Diamond (Cu-CD) and Molybdenum-Diamond (Mo-CD). In particular, Mo-CD may provide interesting properties as to mechanical strength, melting temperature, thermal shock resistance and, thanks to its balanced material density, energy absorption. The research program carried out on these materials at CERN and collaborating partners is presented, mainly focusing on the theoretical investigation, material characterization, and manufacturing processes.
	Slides THOBB03 [3.948 MB]