Beam Intercepting Devices @ CERNAntonio PERILLO-MARCONE, Marco CALVIANI
Engineering Department (EN)Sources Target Interaction (STI) Group
Target, Collimator & Dumps (TCD) Section
~250 devices scattered from the Linac chopper dump (3 MeV)
to the LHC main dump (7 TeV)
Materials: from LD graphite (1.0 g/cm3) to Ir (22 g/cm3)
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CERN’s accelerator complex
Beam Intercepting Devices
Safety function
Beam stoppers
Beam dumps
Beam cleaning &
control
Collimators
Scrapers
Strippers
Slits
Physics
Particle producing
targets
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Main focusing areas
Operation Projects
R&D activities
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Main challenges in BIDs
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Devices must be able to withstand operation and accident scenarios, plus protect sensitive equipment
1. UHV requirements (10-10 mbar) also in movable parts
2. High energy densities (~kJ/cm3/pulse) as well power densities (several MW/cm3)
3. High beam intensity/energy (~500 MJ for LHC dump)
4. High average deposited power (~250 kW for LIU SPS beam dump or ~350 kW for Beam Dump Facility)
5. Physics requirements, often implying the use of non-structural materials (Pb or Ir)
6. Impedance, especially for LHC
7. Radiation damage on absorbing materials
Examples of activities (not exhaustive list)
• Completed
• Linac4 main dump
• PS booster external dump
• SPS high energy beam dump replacement
• Ongoing
• PS Internal Dump
• SPS internal dump
• SPS → LHC Transfer Lines Collimators
• LHC injection protection absorber
• Antiproton Decelerator target upgrade
• n_TOF target upgrade
• Future (not confirmed yet)
• BDF target
• LHC dump upgrade
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Graphite core (SGL4550) shrink-fitted into 304L cylinder – helicoidally
rectangular channel for water cooling (30 l/min)
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Linac4 main beam dump (160 MeV )
Linac4 dump core
Core after assembly and shrink-fitting
Dump core installation in the tunnel
Max T ~300 ºC
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PS Booster external dump
1014 p/pulse, ~10 kW beam
Dump has been installed in 2013 in order to cope
with high intensity beams
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Dump design and installation
Air$Handling$Unit$and$Beam$Pipe$
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Dump AHU
CuCrZr dump core being installed
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Beam
PS internal dump
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SPS internal beam dump (TIDVG)
Main dump of the SPS machine (400 GeV/c)
Employed on a regular basis for beam commissioning and machine development
Located in the main vacuum of the machine (~10-8 mbar)
Highly radioactive, ~30 mSv/h outside the shielding
New design for 2017-2018 (TIDVG#4)
Further upgrade >2020 (TIDVG#5-LIU)
TIDVG#4 (for 2017-2018 operation)
3500mm Graphite
400mm CuCrZr
400mm Inermet
Seamless cooling pipes
(clamped to copper core)
Seamless SS tube
(vacuum chamber)
Main features:
CuCrZr as absorbing block (integrated with core)
Seamless SS vacuum chamber around dump
(minimum risk of leaks)
Fast manufacture (material procurement critical)
T sensors on all inner parts and SS tube
Bellows welded
around pipes
60 kW average power
Up to 4 MJ/pulse
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SPS Dump – TIDVG#5DUMP CORE
(5 m long)
Mock-up assembly
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µCT
3D CC
3D CC
New TIG weld design
TCDIL prototypeTCDIL jaw
TCDIL Tables
IntegrationThermo-structural simulations
SPS → LHC Transfer Lines Collimators (TCDIL)
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LHC injection protection absorber (TDIS)
ModulesModule support
Standard LHC jacks
Girder
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LHC injection protection absorber (TDIS)
Injected
beam
Low Z jaws
(2 blocks of graphite per jaw)0.9 m Ti6Al4V
0.7 m CuCrZr
Ion
pump
Transitions
TBD
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Collimation system
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Halo cleaning vs. quench limits (SC machines)
Passive machine protection
Concentration of losses/activation in controlled areas
Reduction total dose on accelerator equipment
Cleaning physics debris (for colliders)
Optimise background in the experiments
Beam tail/halo scraping, halo diagnostics
- 375 MJ/beam <2019
- 520 MJ/beam (2021-2024)
- 720 MJ/beam >2026
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Each collimator jaw designed (and tested!) to cope
with:
o 10 kW steady losses of 1 hour
o Direct beam impact at injection and during
asynchronous beam dumps at 7 TeV
R&D related to BIDs
Activities are Operation or Project driven, focusing on
optimising the reliability and respecting the functional
specification of the BID
Absorbing blocks (from graphite to high-Z material)
Innovative production processes that improve heat conduction
Energy deposition studies (including radiation damage),
FEM and thermo-mechanical studies on BIDs (plus
design, procurement, assembly, testing & installation)
“Innovative” developments in recent times, from
production to inspection with synchrotron radiation &
neutrons
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HIRADMAT TESTING
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TDIS
TZM backstiffener
CuCrZr absorberTiGr5 clamps
8 mm @injection
~100 mm @physics
Graphite SGL7550
Beam test of coating on collimators jaws
HiRadMat 35 surface assembly, TNC installation and experiment
completion
Assessment of coating
resistance to high intensity
proton beams (TDI-driven
experiment)
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Graphite SGL7550 + Cu (2.5 mm) Graphite SGL7550 + Mo (2.5 mm)
Tatsuno AC150 + Mo (2.5 mm)
SiC-SiC (KEK/JPARC)
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Surface damage detail in Cu coating: grazing impact
Microscopic analysis confirms Cu coating melting as
predicted by simulations
Mo coating not melting, as predicted, but appearing to
have spallation damage
Surface damage detail in Mo coating: tilted impact
Upstream
Upstream Middle
Melting and later
solidification
Limit of damage area
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AD-target prototyping – HRMT48
Experiment to be executed during W39 (end of September 2018)
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n_TOF target #3 – HRMT46
As requested by the reviewers, beam test
being prepared for W39 (end of September
2018)
All on track
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SPECIFIC BEAM TESTING
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BDF prototype target
Prototype target being assembled
Target core will be received mid-July
for the next steps (instrumentation,
dry-run)
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BDF T6 Target in TCC2
Staubli plug-in with:
- 2 water connectors DN16
- 16 optical fibers connectors
- 3 (x48) electrical connectors
TZM & W blocks cladded
with Ta or Ta2.5%
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POST IRRADIATION
EXAMINATIONS
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n_TOF neutron imaging
Neutron imaging run at n_TOF EAR2 (August 2017)
Very successful run, demonstrating the capability for using this technique on highly radioactive samples –totally complementary to x-day due to neutron’s nature
Spent AD-target (10 mSv/h) HRMT42 (400 uSv/h)
iridium
Ti64
tantalum
copper foils
Ti64 container
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Long-term radiation damage campaigns
BLIP#1 executed in January-June 2017
Materials:
Ir, TZM, CuCrZr, Si
Also: Graphite, Be, Ti alloys, Al, SiC-coated C
PIE (2018):
Mechanical testing
Microstructural characterization
Thermal evaluation
Participants:
BNL, PNNL, FRIB, ESS, CERN, JPARC, STFC, Oxford, LANL
Complement long-term radiation damage effects
on materials used for targets (AD-target, BDF),
dump/absorbers applications (TIDVG) and
graphite
Study of evolution of deformation and
fracture for irradiated materials at different
temperatures for future targets and dump
application
Assess bulk mechanical properties of irradiated
materials
4-points bending test 800°C + Micro
observations
Objective & Mean
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Long-term radiation damage campaigns
TZM
CuCrZr
Si poly
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Perspectives for 2018
BLIP#2 irradiation campaign
TaW (2.5%)
Used as cladding material for BDF target
Mo-coated CFC & Mo-coated MoGr.
CFC used as absorbing material in primary and secondary
collimators
Test: Mo adherence on CFC vs MoGr.
Monocrystalline Silicon
Execute post-irradiation experiments for
BLIP#1 at PNNL
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Conclusions
• Several projects for Beam Intercepting
Devices managed by our team
• Responsible for the devices from A to Z
• Several R&D activities ongoing
• Material testing and characterisation is vital
for some devices
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Thank you for your attention.