IPAC2016 - List of Authors (Steele, G.E.)

Paper	Title	Page
TUPMB052	High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers	1218
	F.L. Maciariello, O. Aberle, M.E.J. Butcher, M. Calviani, R. Folch, V. Kain, K. Karagiannis, I. Lamas Garcia, A. Lechner, F.-X. Nuiry, G.E. Steele, J.A. Uythoven CERN, Geneva, Switzerland
	In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the results and their correlation with numerical simulations will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB052
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TUPMR050	Upgrades to the SPS-to-LHC Transfer Line Beam Stoppers for the LHC High-Luminosity Era	1367
	V. Kain, R. Esposito, M.A. Fraser, B. Goddard, M. Meddahi, A. Perillo Marcone, G.E. Steele, F.M. Velotti CERN, Geneva, Switzerland
	Each of the 3 km long transfer lines between the SPS and the LHC is equipped with two beam stoppers (TEDs), one at the beginning of the line and one close to the LHC injection point, which need to absorb the full transferred beam. The beam stoppers are used for setting up the SPS extractions and transfer lines with beam without having to inject into the LHC. Energy deposition and thermo-mechanical simulations have, however, shown that the TEDs will not be robust enough to safely absorb the high intensity beams foreseen for the high-luminosity LHC era. This paper will summarize the simulation results and limitations for upgrading the beam stoppers. An outline of the hardware upgrade strategy for the TEDs together with modifications to the SPS extraction interlock system to enforce intensity limitations for beam on the beam stoppers will be given.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR050
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TUPMW006	Power Deposition in LHC Magnets Due to Bound-Free Pair Production in the Experimental Insertions	1418
	C. Bahamonde Castro, B. Auchmann, M.I. Besana, K. Brodzinski, R. Bruce, F. Cerutti, J.M. Jowett, A. Lechner, T. Mertens, V. Parma, S. Redaelli, M. Schaumann, N.V. Shetty, E. Skordis, G.E. Steele, R. van Weelderen CERN, Geneva, Switzerland
	The peak luminosity achieved during Pb-Pb collisions in the LHC in 2015 (3x1027cm^-2s⁻¹) well exceeded the design luminosity and is anticipated to increase by another factor 2 after the next Long Shutdown (2019- 2020). A significant fraction of the power dissipated in ultra-peripheral Pb-Pb collisions is carried by ions from bound-free pair production, which are lost in the dispersion suppressors adjacent to the experimental insertions. At higher luminosities, these ions risk to quench superconducting magnets and might limit their operation due to the dynamic heat load that needs to be evacuated by the cryogenic system. In this paper, we estimate the power deposition in superconducting coils and the magnet cold mass and we quantify the achievable reduction by deviating losses to less sensitive locations or by installing collimators at strategic positions. The second option is considered for the dispersion suppressor next to the ALICE insertion, where a selective displacement of losses to a magnet-free region is not possible.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers

1218

F.L. Maciariello, O. Aberle, M.E.J. Butcher, M. Calviani, R. Folch, V. Kain, K. Karagiannis, I. Lamas Garcia, A. Lechner, F.-X. Nuiry, G.E. Steele, J.A. Uythoven
CERN, Geneva, Switzerland

In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the results and their correlation with numerical simulations will be presented.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB052

Export •

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

TUPMR050

Upgrades to the SPS-to-LHC Transfer Line Beam Stoppers for the LHC High-Luminosity Era

1367

V. Kain, R. Esposito, M.A. Fraser, B. Goddard, M. Meddahi, A. Perillo Marcone, G.E. Steele, F.M. Velotti
CERN, Geneva, Switzerland

Each of the 3 km long transfer lines between the SPS and the LHC is equipped with two beam stoppers (TEDs), one at the beginning of the line and one close to the LHC injection point, which need to absorb the full transferred beam. The beam stoppers are used for setting up the SPS extractions and transfer lines with beam without having to inject into the LHC. Energy deposition and thermo-mechanical simulations have, however, shown that the TEDs will not be robust enough to safely absorb the high intensity beams foreseen for the high-luminosity LHC era. This paper will summarize the simulation results and limitations for upgrading the beam stoppers. An outline of the hardware upgrade strategy for the TEDs together with modifications to the SPS extraction interlock system to enforce intensity limitations for beam on the beam stoppers will be given.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR050

Export •

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

TUPMW006

Power Deposition in LHC Magnets Due to Bound-Free Pair Production in the Experimental Insertions

1418

C. Bahamonde Castro, B. Auchmann, M.I. Besana, K. Brodzinski, R. Bruce, F. Cerutti, J.M. Jowett, A. Lechner, T. Mertens, V. Parma, S. Redaelli, M. Schaumann, N.V. Shetty, E. Skordis, G.E. Steele, R. van Weelderen
CERN, Geneva, Switzerland

The peak luminosity achieved during Pb-Pb collisions in the LHC in 2015 (3x1027cm^-2s⁻¹) well exceeded the design luminosity and is anticipated to increase by another factor 2 after the next Long Shutdown (2019- 2020). A significant fraction of the power dissipated in ultra-peripheral Pb-Pb collisions is carried by ions from bound-free pair production, which are lost in the dispersion suppressors adjacent to the experimental insertions. At higher luminosities, these ions risk to quench superconducting magnets and might limit their operation due to the dynamic heat load that needs to be evacuated by the cryogenic system. In this paper, we estimate the power deposition in superconducting coils and the magnet cold mass and we quantify the achievable reduction by deviating losses to less sensitive locations or by installing collimators at strategic positions. The second option is considered for the dispersion suppressor next to the ALICE insertion, where a selective displacement of losses to a magnet-free region is not possible.

DOI •

reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW006

Export •

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