1. EuCARD 1st Annual Meeting
European Coordination for Accelerator Research and Development
Highlight talk 1 WP8:
Advanced Materials and Collimators for the LHC
EuCARD 1st Annual Meeting
14th April 2010
Rutherford Appleton Laboratory (RAL), Oxfordshire-UK
Dallocchio, A. Bertarelli (CERN)
On behalf of WP8 ColMat collaboration

2. Outline Objectives Proposed Design for New Collimators
Numerical Simulations
Prototyping
Advanced Materials R&D
Future outlook
Conclusions 2 2

3. EuCARD WP8: Main Goals
Identify and characterize advanced materials for high power accelerators under extreme conditions.
Predict residual dose rates for irradiated materials and their life expectancy.
Design, construct and test collimator prototype(s) for upgraded LHC performances.
Design, construct and test one cryogenic collimator prototype for use in FAIR and possibly LHC.
Develop crystal engineering solutions for collimation.
5 Dec 08
R. Assmann

4. Design of New LHC Collimators
Left Jaw
Right Jaw
Vacuum tank
Existing LHC collimator with graphite-based Jaws
Particle beam axis 4

5. Design of New LHC Collimators
Focus on most critical component: Collimator jaw
Modular design (a common baseline for the jaw assembly allows the use of alternative materials for the jaw).
Back-stiffener concept to allow maximum geometrical stability (improves collimator efficiency).
Optimized internal cooling circuit to absorb very high heat-loads.
Integrated BPMs to minimize set-up time. 5

6. Fine adjustment system
Collimator Jaw Design
Jaw with 3 Segments on 2 intermediate adjustable support. Modular design allowing choice of alternative materials
Fine adjustment system
Mo Back-Stiffener
Segmented jaw: each piece independently supported on the back stiffener. Enhanced geometrical stability 6 6 6

7. Collimator Jaw Design
Jaw with 3 Segments on 2 intermediate adjustable support. Modular design allowing choice of alternative materials
Each sector independently cooled by a brazed cooler
Jaw
Jaw - Stiffener
Machined cooling circuit with brazed covers
Back - Stiffener 7 7 7

8. Numerical simulations
FLUKA model of complete Phase II collimator
Thermal deflection
(Steady-state 1 hr beam life time)
Courtesy L. Lari, F. Cerutti – CERN Fluka team
Total deposited power e11 p/s)
~100 kW
Max. thermal deflection:
~30µm

9. Thermo-mechanical analyses
Preliminary simulations of direct 7 TeV beam impact (200 ns): SiC gives promising results (no melting as opposed to Glidcop jaw). Simulations with hydrodynamic codes + dynamic characterization of the materials + HiRadMat tests are foreseen.
Glidcop Jaw
Temperature distribution in case of Asynchronous Beam Dump at 7 TeV
Max Pressure increase of cooling water:
~60bar
SiC Jaw
Maximum principal stress distribution in case of Asynchronous Beam Dump at 7 TeV
~25bar 9 9 9

10. Thermo-mechanical analyses
Preliminary simulations of direct 7 TeV beam impact (200 ns): SiC gives promising results (no melting as opposed to Glidcop jaw). Simulations with hydrodynamic codes + dynamic characterization of the materials + HiRadMat tests are foreseen.
Melted region (grey)
5mm
Affected region (grey):
Thermal stresses exceeding tensile strength
Glidcop
SiC 10 10 10

11. Thermo-structural FEM analyses including hydrodynamic effects (phase changes, shock waves…) is necessary!

12. Advanced numerical simulations
FEM simulation with explicit formulation and hydrodynamic approach to simulate shock wave induced by beam impact and to assess structural damage.
Numerical simulation to be validated via HiRadMat experiments.
Pressure
Material EOS to describe hydrostatic stress tensor r
deletion
Beam impact
Courtesy L. PeroniA, M. ScapinA, N. TahirB
APOLITECNICO DI TORINO
B GSI

13. Prototyping
BPM functional prototype assembled and installed in SPS. First electrical tests provide promising results. 13 13

14. Prototyping
1st full prototype of new collimator under manufacturing at CERN workshop. Ready for tests end 2010 (RF impedance, BPMs, motorization…) 14 14

15. Advanced Materials R&D
Jaw materials (goals)
Tailored electrical conductivity to improve RF stability.
High thermo-mechanical stability and robustness.
Higher density (high-Z) to improve collimation efficiency.
Strong resistance to particle radiation. 15

16. Mono-crystalline diamond particles (~100mm)
Advanced Materials R&D
Metal- diamond composites are advanced thermal management materials usually obtained by liquid metal pressure infiltration or hot pressing…
Courtesy L. Weber – EPFL
Mono-crystalline diamond particles (~100mm)
Hydraulic pressure
Vacuum chamber
Graphite Heater
Graphite
die
Punch
Powder
Courtesy E. Neubauer – AIT 16

17. Advanced Materials R&D
Intensive new Materials Characterization in collaboration with several institutes (AIT, EPFL, GSI, RRC-KI, PoliTo)
Cu-CD
Liquid Infiltration (EPFL: Al-CD and Ag-CD as possible alternatives)
Hot Pressing (AIT)
SiC
Sintered vs. CVD (suitable suppliers under evaluation)
GlidCop
Molybdenum
Copper Diamond Composite
Silicon Carbide

18. Advanced Materials R&D
Ongoing Activities
Brazing
Tests already performed: Cu/SiC, CuCD/SiC, CuCD/Cu…
Simulation of brazing processes ongoing
Coatings
Optimization of coatings for improved Cu/Glidcop brazing (CERN)
Materials Characterization
Thermo-physical Properties (CERN, AIT, EPFL)
Dynamic Characterization and Shock-wave Simulations (PoliTo)
Materials Irradiation (KI, GSI, AIT)
Work-plan established on ColMat Meeting 26/02/2010

19. Advanced Materials R&D
Radiation hardness is a critical aspect for the lifetime of C-C jaws used for Phase I collimators …Large Test campaign is under way
Courtesy
Kurchatov Institute
According to data available in literature all potential materials (SiC, Copper, Diamond) exhibit good behaviour against radiation …
Lower doses on surrounding equipment will extend lifetime of critical components (e.g. Warm Quadrupoles) 19

20. Advanced Materials R&D
Present and Future Outlook
Manufacturing of Metal-CD samples (AIT)
Large Cu-CD tiles produced by AIT
Optimization of CD content (AIT / EPFL)
Irradiation studies (KI, GSI)
Samples to be provided by AIT
Tests to be carried out by KI and GSI (results by Apr. ‘11)
Material characterization
Material candidates fully characterized (thermo-physical and mechanical properties). AIT, PoliTo, CERN, EPFL
Simulations
In-depth Hydrodynamic FEM simulations (CERN, PoliTo; GSI)
Courtesy
AIT 20 20

21. Conclusions I
Jaw design based on a modular concept, allowing different materials to be adopted.
BPMs integrated to reduce set-up time. Only way for fast set-up at high energies and intensities.
Particular care devoted to flatness control, minimization of induced deflection, heat evacuation.
BPM functional prototype built, installed and being tested in the SPS.
New full collimator prototype under manufacturing. Ready End 2010 for HiRadMat tests. 21 21 21

22. Conclusions II
Material R&D program in progress, but lot of work still ahead of us. Main axes are:
Development of Metal-CD (Cu-CD, Ag-CD, Mo-CD?)
Assembling different materials (SiC, SiC coating, brazing)
Irradiation tests and simulations
FEM and hydrodynamic simulations.
Tracking simulations 22 22

23. Thank you for your attention!23

24. Advanced Materials R&D
Diamond-based metals
Ceramics
Silicon Carbides
Carbon/Carbon
Metals 24