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.