SPS Beam Dump Facility Project Design Challenges M. Calviani (CERN) on behalf of the BDF Project team
Outlook § BDF as a high intensity slow extracted beam in the CERN’s NA § Beam operational scenarios and compatibility with existing FT programs § Design of the BDF target and prototyping § Design process & optimization for the BDF target complex § Conclusions 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 2
BDF work packages § Defined based on the identified challenges: 1. Extraction and beam transfer 2. Target and Target complex 3. Radiation protection 4. Safety engineering 5. Integration 6. Civil engineering 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 3
CERN SPS today LINAC4 LINAC3 LEIR AD 2 ELENA TI2: LHC ISOLDE nTOF Beam 1 HiRadMat LHC R av = 1.1 km LSS6: fast extraction AWAKE LSS5 LSS1: injection, (formerly CNGS) internal beam dump LSS4: fast extraction TI8: LHC BEAM LSS3: RF DIRECTION Beam 2 LSS2: slow-extraction Beam Dump Facility North Area (NA): max 450 GeV [1] J.B. Adams, The CERN 400 GeV Proton Synchrotron, 1977 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 4
18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 5
Beam losses (and activation) 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 6
Extraction from SPS for FT physics § Slow extraction is used to deliver a constant flux of particles to FT experiments over many seconds: § From the SPS we typically extract up to ~3*10 13 p + over 4.8 s, i.e. while the beam circulates for over 200,000 turns § Unlike single turn extraction, the slow extraction process is intrinsically lossy : § We cannot (yet!) create a clear temporal or spatial separation in the beam to extract cleanly § Beam loss from slow extraction is unavoidable and has to be controlled and optimized : § Induced activation in SPS Long Straight Section 2 increases proportionally to the beam loss on the septum 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 7
SPS super-cycles 2015 in a period without LHC filling beam intensity Fixed Target Fixed Target ~40 kW average main magnet current test beam test beam § Duty cycle of fixed target beam limited by RMS power dissipation in SPS magnets § Cycles for test beams with low power consumption are inserted in the sequence § Different configuration during LHC filling 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 8
SPS – present challenges § Regaining experience at SPS of operating slow-extracted beams for Fixed Target physics at high intensity § Optimisation of extraction losses and induced activation § Monitoring of machine performances and interlocking § Improving machine stability and reproducibility ( spill quality ) § Maintenance of equipment in activated areas § Doing all the above with a truly multi- cycling SPS 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 9
Proton sharing scenarios Maximum number of protons on target for SHiP Baseline scenario with FT flat-top 6*10 19 p/y of 9.7 s à conservative assumption for TCC2 target experiments CERN-SHiP-NOTE-2015-004 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 10
Proton sharing scenarios Higher proton rate for TCC2 primary targets experiment SHiP goal Shorter flat-top for TCC2 fixed target cycle implies § Higher average proton flux and higher activation in the splitter region § Increasing total POT for SHiP and TCC2 experiments, increasing radiation in SPS CERN-SHiP-NOTE-2015-004 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 11
Target design challenges and issues § Long-optimisation for the design of the target sandwich § Important compressive stress at the core centre § Very high values of tensile forces on the cladding § Initial Ta cladding removed in favour of Ta(2.5)W § Target prototype beam tests during 2018 (PIE 2019) E. Lopez-Sola 20/09 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 12
Dilution beam target images 50 mm radius, 8 mm 1sigma, 4 turns in 1 second 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 13
BDF T6 target test § Reliability of the target is a critical aspect of the design of BDF à representative beam test required § HiRadMat cannot be used due to availability of fast extraction only § A dedicated beam test area in the TCC2 T6 line will be realized during the 2017-2018 beam shutdown § Instrumented prototype target – beam on target summer 2018 BDF setup E. Lopez-Sola 20/09 M. Casolino 20/09 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 14
Requirement for BDF target shielding bunker Target hall surface Beam direction He-vessel wall Target § Prompt dose on the top of the surface hall shall be such as to classify it as supervised area § Concrete works of the target station must not be considered as radioactive (maintenance) § Flexibility for future use and reconfiguration 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 15
Cooling and ventilation aspects § Ventilation scheme according to ISO 17873:2004 implemented § Reduction of environmental impact à target bunker will be embedded in a dynamic He-gas containment (online purification) § Detailed study in 2018, construction of a prototype tank and circulation in 2019 P. Avigni 19/09 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 16
General RP considerations for BDF § Unprecedented prompt and residual dose rate values PROMPT AND AIR AND HELIUM RESIDUAL ACTIVATION § Radiation protection RADIATION aspects are of RADIATION PROTECTION paramount importance for the validation of WATER AND RADIOACTIVE GROUND WASTE the design and for the ACTIVATION Project M. Casolino 20/09 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 17
Magnetized hadron absorber Hadron absorber magnetized as well to catch muons before they open up 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 18
G. Gilley (RAL) Schematics of BDF target bunker elements 11.2 m 1.4 T 7.9 m Passive cast iron Start of experimental area assembly Magnetisation coil Primary area tunnel Proximity shielding cast iron US1010 hadron absorber Target (320 kW) Beam delivery 7.9 m shielding (1.8 T zone) 25 kW, water cooled 3.2 m 11.2 m 6.4 m 4.5 m 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 19
Target complex design challenges § Demonstrate the feasibility of the construction, operation and maintenance of the BDF TC along with decommissioning 1. Crane handling § TC travelling crane for the movements of all critical elements 2. Trolley concept § Target and main services installed on mobile trolleys running on rails (similar to standard spallation sources, but lateral ) § Hadron absorber magnetization § CERN placed a contract with Oxford Technologies (UK) early 2017 for the joint execution of the study – to be completed in 02/2018 to feed into CERN’s service integration studies 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 20
Crane concept - overview Services Area Cooldown Area Beam Line Helium Vessel 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 21
Crane concept – helium vessel components Above Coil Mobile Shielding Shielding 8 m 8 m 12 m Collimator Target + water cooled shielding and collimators installed on US1010 pillars, w/ space routing for Shielding Proximity services Target Shielding 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 22
Crane concept – target access Vessel Lid Crane Target Mobile Shielding Proximity Shield Block 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 23
Crane concept – Proximity shielding 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 24
Crane concept – target pipework Vertical plugin system Proximity shielding water Target helium Target water 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 25
Trolley concept - overview In beam position Smaller cool-down area and services room included for non-target operations. Beam Line Hot Cell Out beam position Helium Vessel Trolley 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 26
Trolley concept – helium vessel All of the In-Vessel Mobile components are still moved Shielding Concrete by the crane Shielding Above Coil Shielding Magnetic Coil Collimator (and surrounding US1010 shielding) Shielding Remaining space inside the Proximity helium vessel is filled with Shielding Cast Iron shielding blocks (water-cooled) 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 27
Trolley concept – proximity shielding § “Chimneys” added to the top of the proximity shielding for water cooling § Less connection inside the vessel 18-22/09/2017 M. Calviani - NBI2017/RaDIATE - BDF Design Challenges 28
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