1. Conceptual design of the CERN’s Search for Hidden Particles (SHiP) experiment target complex M. Calviani (CERN) 6 th High Power Targetry Workshop Oxford, 10-15 April 2016 http://ship.web.cern.ch/ship/

2. Outline  Introduction to the SHiP physics case  Main experimental requirements for Hidden Sector exploration  The SHiP production target/dump  The SHiP target facility design  Conclusions and perspectives 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 2

3. Hidden sector – “discovery” physics 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 3  Well known that Standard Model, despite its great successes, is still incomplete:  Neutrino masses and oscillations, absent in the SM  Dark matter, absent in the SM  Baryogenesis, absent in the SM  Different anomalies: muon magnetic moment, LSND,...  Energy scale for new physics is not certain and can vary by many orders of magnitudes

4. Hidden sector – “discovery” physics  Proposition of a new facility/experiment to search for Hidden Particles and for tau neutrino physics at the “intensity” frontier  Rather than being heavy, could new particles be light but very weakly interacting? 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 4 Courtesy: SHiP Collaboration

5. HS investigation experimental requirements 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 5  Cosmologically interesting and experimentally accessible m HS ~ O(MeV – GeV)  Hidden particle production in , K, D, B, decays, coupling to photons  High A and Z target  Hidden particle decay  Full reconstruction and identification  Production and decay rates are suppressed relative to SM  Production branching ratios ~O(10 -10 )  Largest possible number of protons on target  Long-lived objects  Large decay volume  Travel unperturbed through ordinary matter  Allows filtering out background  Background suppression is a key aspect

6. SHiP experiment proposal 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 6  Proposition of beam dump experiment at CERN SPS with ~2*10 20 protons on target  ~O(1000) improvement over any previous searches  High energy (400 GeV/c) to increase c quark cross- section  Studied siting at FNAL and JPARC, but lower energy unfavourable  Crucial design parameters: residual and  fluxes  Reduction of neutrinos from light meson decays  Dense target/dump  Short-lived resonances generate ~10 10  /spill  Active muon shield – ~90 Tm

7. Facility schematic overview 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 7 Courtesy: A. Golutvin (Imperial College) 45 Institutes 243 participants  Heavy target to maximize heavy flavour production (large A) and minimize neutrinos from  /K  Hadron absorber + effective  shield  Slow (and uniform) beam extraction (~1 second), to reduce occupancy in the detector

8. SHiP target complex  Target and proximity shielding inside a He- vessel (T2K experience!)  Target located 10 m below ground floor  Cast-iron proximity shielding and hadron absorber (~460 m 3 of Fe!) 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 8

9. The extraction line to target  SHiP extraction line to be installed in the TT20 tunnel (SPS to North Area FT)  Facility requires a new bipolar laminated splitter 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 9 Courtesy: M. Fraser (CERN)

10. Beam dilution on target 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 10  In order to avoid damaging the target, beam dilution on target is required  Presently considered is an Archimedean spiral, 5-35 mm radius (1  = 6 mm) with constant arm separation and uniform speed

11. SHiP beam/target configuration  SHiP target is effectively a high pulse intensity “spallation” target, but whose aim is not to produce neutrons  90% of the beam energy is deposited in the target (~13 kW/cm 3 ) – 2.56 MJ  Super cycle average beam power (355 kW) Baseline Beamprotons Momentum [GeV/c]400 Beam Intensity [10 13 p/cycle]4.0 Magnetic cycle length [s]7.2 Spill duration [s]1.0 Expected r.m.s. spot size (H/V) [mm]6/6 Average beam power on target (deposited) [kW]355 (320) Average beam power on target during spill (deposited) [kW]2560 (2300) 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 11

12. SHiP vs. CHARM vs. DONUT beam DONUT *CHARM **SHiP Target materialW-alloy Cu (variable  ) TZM + pure W Momentum (GeV/c)800400 Intensity0.8*10 13 1.3*10 13 4*10 13 Pulse length (s)2023*10 -6 1 Rep. rate (s)60~107.2 Beam energy (kJ)10208302560 Avg. beam power (spill) (kW)513.4*10 7 (fast)2560 Avg. beam power (SC) (kW)1769355 POT (total)Few 10 17 Few 10 18 2*10 20 * http://www-donut.fnal.gov/http://www-donut.fnal.gov/ ** http://cds.cern.ch/record/205527/files/CM-P00068733.pdf?version=1http://cds.cern.ch/record/205527/files/CM-P00068733.pdf?version=1 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 12

13. SHiP CDR target overview  Target is the single most critical component of the target complex  10  nuclear int. length long production target  High-Z target, hybrid solution composed of TZM (Moly alloy) & pure W (Ta cladded)  40x40 cm 2, segmented target  58 cm TZM (13 layers) + 58 cm W (4 layers)  Water cooled (in CDR) to dissipate the ~320 kW energy deposition  O(85 mm) water gaps – more are unacceptable for physics 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 13

14. 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 14 He circulationWater circulation Top view Lateral view Transversal view  Contrary to a conventional “neutrino” target, SHiP does want to minimize light mesons:  High Z to avoid  /K escape  Significant transversal cross-section

15. SHiP target updated FEM 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 15  Beam characteristics generates significant oscillating temperature fields, max temperature reached after 5 pulses TZM W

16. 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 16 Minimum principal stresses (compression) Maximum principal stresses (tensile) #9 #13 Further optimisation required -- Ta yield limit

17. SHiP target CFD studies 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 17  Optimal flow rate 50-80 l/s (180-290 m 3 /h)  Two inlets/outlets, 8 cm Ø  High flow required to decrease temperature at the boundary of the plates in the gaps (  T~0-3 °C) 50 l/s Further optimisation required  High temperatures expected at the water/blocks boundaries  For 180 m 3 /h, almost 200 °C is reached  Loop need to be pressurized (O(15-20 bar))

18. Radiation damage 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 18  O(1 DPA) over a significant volume  Appropriate testing shall be foreseen in the Comprehensive Design Phase – already preliminarily started within RaDIATE  Not a problem according to ISIS experience – but what about TZM? Neutron flux 10 21-22 n/cm 2

19. SHiP target complex requirements  Production target installed inside an underground iron-shielded bunker, accessible from top  Fully remote handling/manipulation of the target and shielding from the target hall (40 ton fully redundant crane)  Target residual dose rate O(50 Sv/h)  Helium environment inside the target bunker  Reduction of air activation and corrosion  Ventilation system according to ISO17873  Dynamic confinement 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 19 See H. Vincke presentation

20. SHiP target bunker 30 m 40 m 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 20

21. 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 21  Target shielding conceived to be compliant with radiation protection requirements

22. SHiP proximity shielding 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 22  O(50 kW) deposited, water cooling needed  Cast iron blocks with embedded SS pipes  Maximize weight (~35 tons/block) to reduce handling of highly radioactive (O(Sv/h)) blocks

23. SHiP status  Project endorsed by the SPSC (March 2016)  Technical Proposal (http://arxiv.org/abs/1504.04956) + Addendum (http://ship.web.cern.ch/ship/Document/SPSC-P-350-ADD-2.pdf )http://arxiv.org/abs/1504.04956http://ship.web.cern.ch/ship/Document/SPSC-P-350-ADD-2.pdf  Physics Proposal (http://arxiv.org/abs/1504.04855)http://arxiv.org/abs/1504.04855  Recommend to proceed towards the Comprehensive Design Report  CERN Taskforce analysed the feasibility of the project (EDMS 1369559)1369559  Target design, radiological aspects, civil engineering, beam extraction, costs and manpower  Details on target & target complex in EDMS 15132941513294  If approved in 2019, the project would take 8 years to construct (beam on target 2025/6) M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 2313 April 2016

24. SHiP schedule 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 24  10 years from Technical Proposal to data taking  Optimised for minimal interference with operation of North Area  Preparation of facility in four and separate WP  Use of Long Shutdown 3 for junction cavern  Comprehensive Design Study (2016-2018)  Construction/production >2021  Data taking 2026 (start of HL-LHC era) Courtesy: R. Jacobsson (CERN)

25. Perspectives for R&D future activities Design-critical R&D to be carried out in the next 2-3 years: 1.Pursue design of the production target towards a robust configuration  Dedicated material investigation, detailed FEM, fatigue analysis, dynamic studies, study advanced solutions, etc. 2.Investigate viability of a He-cooled target  Simplification of water activation and reduced risk of circuit contamination 3.Prototyping He-vessel for the target bunker 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 25

27. W/Mo Target~1m Fe ~5m Detector volume ~100m e.m, hadrons K L, K S, , n, ,K Vacuum neutrino Active muon shield (magnetic deflection) O(50)m muon Occupancy + combinatorial K L, K S, , n,  Tau neutrino Detector ~5m neutrons

28. SHiP target material properties 13 April 2016 M. Calviani - SHiP Target Complex - 6th High Power Targetry Workshop 28  Stress-relieved tempers for both TZM and W  Lots of information missing, properties depend on the “deformation” processes and the final blocks shapes  Significant mechanical testing campaign to be foreseen during a TDR phase  Tensile and compression curves in relevant T range (irradiated and non-irradiated)  Fatigue (thermal cycles)  Fracture mechanics tests, impact toughness (DBTT), etc.  Blocks assembly shapes will have to be reviewed based on what suppliers could provide (ongoing discussions)