IPAC2011 - List of Authors (Mariani, N.)

Paper

Title

Page

High Energy Beam Impacts on Beam Intercepting Devices: Advanced Numerical Methods and Experimental Set-up

1614

A. Bertarelli, V. Boccone, F. Carra, F. Cerutti, A. Dallocchio, N. Mariani, M.A. Timmins
CERN, Geneva, Switzerland
L. Peroni, M. Scapin
Politecnico di Torino, Torino, Italy

Funding: This work has been carried out through of the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program.
Beam Intercepting Devices are potentially exposed to severe accidental events triggered by direct impacts of energetic particle beams. State-of-the-art numerical methods are required to simulate the behavior of affected components. A review of the different dynamic response regimes is presented, along with an indication of the most suited tools to treat each of them. The consequences on LHC Tungsten Collimators of a number of beam abort scenarios were extensively studied, resorting to a novel category of numerical explicit methods, named Hydrocodes. Full shower simulations were performed providing the energy deposition distribution. Structural dynamics and shock wave propagation analyses were carried out with varying beam parameters, identifying important thresholds for collimator operation, ranging from onset of permanent damage up to catastrophic failure. Since the main limitation of these tools lies in the limited information available on constitutive material models under extreme conditions, a dedicated experimental program is proposed, relying on the HiRadMat test facility at CERN. Experimental aspects such as sample-holder design and test set-up are described.

TUPS037

Preliminary Assessment of Beam Impact Consequences on LHC Collimators

1617

M. Cauchi, R.W. Assmann, A. Bertarelli, R. Bruce, F. Carra, A. Dallocchio, D. Deboy, N. Mariani, A. Rossi, N.J. Sammut
CERN, Geneva, Switzerland
M. Cauchi, P. Mollicone
UoM, Msida, Malta
L. Lari
IFIC, Valencia, Spain

The correct functioning of the LHC collimation system is crucial to attain the desired LHC luminosity performance. However, the requirements to handle high intensity beams can be demanding. In this respect, the robustness of the collimators plays an important role. An accident which causes the proton beam to hit a collimator might result in severe beam-induced damage and, in some cases, replacement of the collimator, with consequent downtime for the machine. In this paper, several case studies representing different realistic beam impact scenarios are shown. A preliminary analysis of the thermal response of tertiary collimators to beam impact is presented, from which the most critical cases can be identified. Such work will also help to give an initial insight on the operational constraints of the LHC by taking into account all relevant collimator damage limits.

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
TUPS036	High Energy Beam Impacts on Beam Intercepting Devices: Advanced Numerical Methods and Experimental Set-up	1614
	A. Bertarelli, V. Boccone, F. Carra, F. Cerutti, A. Dallocchio, N. Mariani, M.A. Timmins CERN, Geneva, Switzerland L. Peroni, M. Scapin Politecnico di Torino, Torino, Italy
	Funding: This work has been carried out through of the European Coordination for Accelerator Research and Development (EuCARD), co-sponsored by EU 7th Framework Program. Beam Intercepting Devices are potentially exposed to severe accidental events triggered by direct impacts of energetic particle beams. State-of-the-art numerical methods are required to simulate the behavior of affected components. A review of the different dynamic response regimes is presented, along with an indication of the most suited tools to treat each of them. The consequences on LHC Tungsten Collimators of a number of beam abort scenarios were extensively studied, resorting to a novel category of numerical explicit methods, named Hydrocodes. Full shower simulations were performed providing the energy deposition distribution. Structural dynamics and shock wave propagation analyses were carried out with varying beam parameters, identifying important thresholds for collimator operation, ranging from onset of permanent damage up to catastrophic failure. Since the main limitation of these tools lies in the limited information available on constitutive material models under extreme conditions, a dedicated experimental program is proposed, relying on the HiRadMat test facility at CERN. Experimental aspects such as sample-holder design and test set-up are described.

TUPS037	Preliminary Assessment of Beam Impact Consequences on LHC Collimators	1617
	M. Cauchi, R.W. Assmann, A. Bertarelli, R. Bruce, F. Carra, A. Dallocchio, D. Deboy, N. Mariani, A. Rossi, N.J. Sammut CERN, Geneva, Switzerland M. Cauchi, P. Mollicone UoM, Msida, Malta L. Lari IFIC, Valencia, Spain
	The correct functioning of the LHC collimation system is crucial to attain the desired LHC luminosity performance. However, the requirements to handle high intensity beams can be demanding. In this respect, the robustness of the collimators plays an important role. An accident which causes the proton beam to hit a collimator might result in severe beam-induced damage and, in some cases, replacement of the collimator, with consequent downtime for the machine. In this paper, several case studies representing different realistic beam impact scenarios are shown. A preliminary analysis of the thermal response of tertiary collimators to beam impact is presented, from which the most critical cases can be identified. Such work will also help to give an initial insight on the operational constraints of the LHC by taking into account all relevant collimator damage limits.

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]