External Review of LHC Collimation Project Oliver Aberle 1th July 2004

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External Review ofLHC Collimation ProjectOliver
Aberle1th July 2004

• Mechanical robustness

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Overview

• Material choice
• Ansys results
• Material for phase 1
• SPS test Robustness
• Beam parameters
• Thermo-mechanical Analysis
• Results
• What can we learn?

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Material choice

• Which material withstands the different LHC beam
  scenarios?

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Material choice

• - Has to withstand 3 major scenarios
• Proton beam at 7 TeV (9.1e11 p, 200ns)
• Beam at Injection (450 GeV, 3.2e13 p)
• Ion beam (e.g. Pb)
• - Other demands
• Vacuum
• Impedance

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Material choice
A 10x10 mm
B 5x5 mm
Finite Element Model 2D MESH 104 parabolic
elements 3 104 nodes 0.05x0.05 mm mesh
size MATERIALS Graphite Beryllium 3D
CFC Graphite matrix with27 in x direction4
in y and z direction Elastic linear law Small
deformations
Free Sliding
Beam
sweeping
Symmetry
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Ansys results
Graphite Slice at 20 cm / 7 TeV
CFC Slice at 100 cm / 450 GeV
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Ansys results
Stress values for different proton load
cases Maximum stress values
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Material for phase 1

• Graphite or Carbon-carbon(very similar
  robustness?!)
• 10 times more robust than next best material (Be)
• Beryllium does not withstand the expected beam
  impact at injection and 7 TeV (Ok for slow losses)

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SPS test Robustness
Vacuum tank
Beam axis
Support
Plug-in system
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SPS test Robustness

• Full size horizontal collimator
• Jaw length 1.2m
• Jaw material CFC
• Movement withLEP motors (2 per jaw)
• Clamped jaws, water cooled

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Beam parameters

• Extraction of 4 72 bunches,1.1 1011 protons
  each (2.4 MJ)
• Robustness test with 5 shots450 GeV, beam size 1
  mm

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Thermo-mechanical Analysis
FEM Model for 3-D analysis
Contact elem. (Friction Therm. Cond.)
Temperature dependent properties
Deposited Power (W/m3)
Pinned Free exp. BC
Cooling pipes
Jaw material
Courtesy A. Bertarelli R. Perret
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Thermo-mechanical Analysis
Dynamic stress Preliminary estimation
Quasi-static Stress
Dynamic stress
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Ansys results
Graphite R4550 Slice at 100 cm / 7 TeV
Graphite R4550 Sy 20,7 MPa A.
Dallocchio A. Bertarelli
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Ansys results
CFC Slice at 100 cm / 450 GeV
CFC AC150 Sy 58,1 MPa
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Ansys results
CFC Slice at 100 cm / 450 GeV
Graphite R4550 Small deformations ux 6
mm
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Ansys results
CFC Slice at 100 cm / 450 GeV
Graphite R4550 Isotropic A. Dallocchio
A. Bertarelli
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What can we learn?

• Robustness
• Material properties (Fluka, Ansys)
• Shower, energy
• Vacuum behaviour
• Collimator
• Cooling
• Shower, energy deposition (Fluka)
• Impedance
• Beam Settings