IPAC2018 - List of Authors (Mazzacano, G.)

Paper	Title	Page
THPAF035	Single-Collimator Tune Shift Measurement of the Three-Stripe Collimator at the LHC	3036
	S. A. Antipov University of Chicago, Chicago, Illinois, USA D. Amorim, N. Biancacci, L.R. Carver, G. Mazzacano, A. Mereghetti, E. Métral, S. Redaelli, B. Salvant, D. Valuch CERN, Geneva, Switzerland
	Several options of low resistivity coating have been proposed for the collimator upgrade of the Large Hadron Collider. In order to study their effect on the beam dynamics a special collimator has been built and installed in the machine. Its jaws are coated with three different materials and can be moved transversely to selectively expose the beam to the chosen coating. We have measured the resistive wall tune shifts of each coating material and compared them with that of a standard Carbon Fibre Composite (CFC) collimator jaw. A resolution of the tune shift of the order of 10^-5 has been achieved in the measurement. The results show a significant reduction of the resistive wall tune shift with novel materials. The largest improvement is obtained with a 5 μm Molybdenum coating of a Molybdenum-Graphite jaw. The observed tune shifts show a good agreement with the impedance model and the bench impedance and resistivity measurements. Obtained results can be used to further improve the precision of the impedance model.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF035
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THPAK092	Analysis on the Mechanical Effects Induced by Beam Impedance Heating on the HL-LHC Target Dump Injection Segmented (TDIS) Absorber	3448
	L. Teofili, M. Migliorati Sapienza University of Rome, Rome, Italy M. Calviani, D. Carbajo Perez, S.S. Gilardoni, F. Giordano, I. Lamas Garcia, G. Mazzacano, A. Perillo-Marcone CERN, Geneva, Switzerland
	The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In such a scenario, critical accelerator devices need to be redesigned and rebuilt. Impedance is among the design drivers, since its thermo-mechanical effects could lead to premature device failures. In this context, the current work reports the results of a multiphysics study to assess the electromagnetic and thermo-mechanical behaviour of the Target Dump Injection Segmented (TDIS). It first discusses the outcomes of the impedance analysis performed to characterise the resistive wall and the high order resonant modes (HOMs) trapped in the TDIS structures. Then, their RF-heating effects and the related temperature distribution are considered. Finally, mechanical stresses induced by thermal gradients are studied in order to give a final validation on the design quality.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK092
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THPAK093	A Multi-Physics Approach to Simulate the RF Heating 3D Power Map Induced by the Proton Beam in a Beam Intercepting Device	3452
SUSPF075	use link to see paper's listing under its alternate paper code
	L. Teofili, M. Migliorati Sapienza University of Rome, Rome, Italy D. Carbajo Perez, F. Giordano, I. Lamas Garcia, G. Mazzacano CERN, Geneva, Switzerland
	The project High Luminosity Large Hadron Collider (HL- LHC) calls for a streaking beam intensity and brightness in the LHC machine. In such a scenario, beam-environment electromagnetic interactions are a crucial topic: they could lead to uneven power deposition in machine equipment. The resulting irregular temperature distribution would gener- ates local thermal gradients, this would create mechanical stresses which could lead to cracks and premature failure of accelerator devices. This work presents a method to study this phenomenon by means of coupled electro-thermo- mechanical simulations. Further, examples of applications on real HL-LHC devices is also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK093
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Single-Collimator Tune Shift Measurement of the Three-Stripe Collimator at the LHC

3036

S. A. Antipov
University of Chicago, Chicago, Illinois, USA
D. Amorim, N. Biancacci, L.R. Carver, G. Mazzacano, A. Mereghetti, E. Métral, S. Redaelli, B. Salvant, D. Valuch
CERN, Geneva, Switzerland

Several options of low resistivity coating have been proposed for the collimator upgrade of the Large Hadron Collider. In order to study their effect on the beam dynamics a special collimator has been built and installed in the machine. Its jaws are coated with three different materials and can be moved transversely to selectively expose the beam to the chosen coating. We have measured the resistive wall tune shifts of each coating material and compared them with that of a standard Carbon Fibre Composite (CFC) collimator jaw. A resolution of the tune shift of the order of 10^-5 has been achieved in the measurement. The results show a significant reduction of the resistive wall tune shift with novel materials. The largest improvement is obtained with a 5 μm Molybdenum coating of a Molybdenum-Graphite jaw. The observed tune shifts show a good agreement with the impedance model and the bench impedance and resistivity measurements. Obtained results can be used to further improve the precision of the impedance model.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAF035

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAK092

Analysis on the Mechanical Effects Induced by Beam Impedance Heating on the HL-LHC Target Dump Injection Segmented (TDIS) Absorber

3448

L. Teofili, M. Migliorati
Sapienza University of Rome, Rome, Italy
M. Calviani, D. Carbajo Perez, S.S. Gilardoni, F. Giordano, I. Lamas Garcia, G. Mazzacano, A. Perillo-Marcone
CERN, Geneva, Switzerland

The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In such a scenario, critical accelerator devices need to be redesigned and rebuilt. Impedance is among the design drivers, since its thermo-mechanical effects could lead to premature device failures. In this context, the current work reports the results of a multiphysics study to assess the electromagnetic and thermo-mechanical behaviour of the Target Dump Injection Segmented (TDIS). It first discusses the outcomes of the impedance analysis performed to characterise the resistive wall and the high order resonant modes (HOMs) trapped in the TDIS structures. Then, their RF-heating effects and the related temperature distribution are considered. Finally, mechanical stresses induced by thermal gradients are studied in order to give a final validation on the design quality.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK092

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPAK093

A Multi-Physics Approach to Simulate the RF Heating 3D Power Map Induced by the Proton Beam in a Beam Intercepting Device

3452

SUSPF075

use link to see paper's listing under its alternate paper code

L. Teofili, M. Migliorati
Sapienza University of Rome, Rome, Italy
D. Carbajo Perez, F. Giordano, I. Lamas Garcia, G. Mazzacano
CERN, Geneva, Switzerland

The project High Luminosity Large Hadron Collider (HL- LHC) calls for a streaking beam intensity and brightness in the LHC machine. In such a scenario, beam-environment electromagnetic interactions are a crucial topic: they could lead to uneven power deposition in machine equipment. The resulting irregular temperature distribution would gener- ates local thermal gradients, this would create mechanical stresses which could lead to cracks and premature failure of accelerator devices. This work presents a method to study this phenomenon by means of coupled electro-thermo- mechanical simulations. Further, examples of applications on real HL-LHC devices is also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK093

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)