1. Report from HEBT Working Group https://edms.cern.ch/nav/P:CERN-0000072786:V0 https://edms.cern.ch/nav/P:CERN-0000072786:V0 B.Goddard, CERN TE/ABT On behalf of Erwin Siesling; Matthew Alexander Fraser; Didier Voulot; Davide Lanaia; Yacine Kadi; Jeremie Bauche; Panagiotis Farantatos; Giovanna Vandoni; Eleftherios Zografos; Angelina Parfenova; Michele Martino; William Andreazza; Richard Mompo; Antti Juhani Kolehmainen; Marc Timmins

2. Contents HEBT technical design review outcome Latest version and (relevant) features of HEBT design Evaluation of low-energy performance Status of HEBT subsystems – Diagnostics – Magnets – Power convertors – Vacuum – Interlocking – Supports and alignment Remaining issues and concerns Conclusions and outlook

3. HEBT technical design review Held on 6 th July 2012 Follow-up of the Conceptual Design Review held (already way back!) on 25 th May 2012 Reviewed the technical designs and system specifications to allow Market Surveys and Invitations to Tender be launched in time (from Autumn 2012). To validate or point out weaknesses

4. Review organisation 09:00 - 09:15 Introduction, schedule and objectives (10+5') 15‘, B.Goddard 09:15 - 09:40 Diagnostic Boxes: detailed design (20+5’) 25‘, J.-J.Gras 09:40 - 10:05 Magnets: ST, MQ and MD magnetic design (20+5’) 25‘ J.Bauche 10:05 - 10:30 Power convertors: technical choices and designs (20+5’) 25‘ M.Martino 10:30 - 10:45 Coffee break 10:45 - 11:00 HIE-ISOLDE HEBT vacuum system (10+5’) 15’ M.Hermann 11:00 - 11:20 Interlocking: system architecture and design (15+5’) 20‘ R.Mompo 11:20 - 11:40 Supports and alignment/survey (15+5’) 20‘ M.Timmins 11:40 - 11:55 Integration: model and known issues (10+5’) 15‘ E.Zografos 11:55 - 12:10 Experimental zone access, beamline controls and SW (10+5’) 15‘ D.Voulot 12:10 - 12:25 Optics: expected performance for 0.3 MeV/u (10+5’) 15‘ A.Parfenova 12:25 - 14:00 Lunch 14:00 - 14:30 Reserve 30' 14:30 - 16:15 Closed review session 16:15 - 16:30 Coffee break 15' 16:30 - 17:30 Open review session and summary

5. Reviewers Review panel – Wolfgang Bartmann, TE/ABT – Lau Gatignon (chair), EN/MEF – Thomas Zickler, TE/MSC – Roberto Kersevan, TE/VSC – Alessandro Dallocchio, EN/MME – Uli Raich, BE/BI – David Nisbet, TE/EPC https://indico.cern.ch/conferenceDisplay.py?confId=194310

6. Reviewers’ conclusions I Instrumentation is on critical path. It could be a potential showstopper for a start-up in 2014. Recommend strongly to order all magnets of the same type in a single contract. The separation between linac and transfer line reviews is in certain aspects artificial. Address planning and resource issues to guarantee a timely design and procurement strategy for the beam instrumentation and its associated electronics. Study the choice of steel type in terms of mechanical and magnetic behaviour for vacuum tubes and diagnostic boxes. Measure field quality of existing 22.5 deg bends at low fields to ensure adequate performance.

7. Reviewers’ conclusions II Check magnetic and mechanical interference of correctors on neighboring equipment, in particular vacuum components and instrumentation. Verify that EM influence of power converters complies to tolerances to be specified by the neighboring experiments. Complete simulations of the effectiveness of cold traps and acoustic delay lines with respect to latency of fast valves. Address all integration issues in detail, including services. Evaluate RP aspects in case of significant increase of primary proton beam intensities. Include magnet non-linearities in optics simulations.

8. Reviewers’ conclusions III

9. Latest HEBT design All details on EDMS (HIE-ISOLDE/HEBT LINES OPTICS AND LAYOUT) – Drawings, layout tables and (new) madx reference optics files

10. Relevant features All beamline elements fully integrated – Some changes to layout to make this possible – included in latest optics versions Integration following element design – Now addressing services, cable connections etc. Reduced drift to experimental station #3 in XT04 – Remove one double period (fewer magnets, save some $$) – Now identical achromat and final focus to XT01 Diagnostic box contents all defined – 4 variants, included in updated specification

11. Stage 2b

12. Evaluation of low-energy performance Recall that baseline HEBT design is 3-10 MeV/u Optics evaluated with 0.3 MeV/u – Increased error contributions from remnant fields, powering ripple, powering accuracy Results shown for XT01

13. X-plane: beam sizes, maximum particle deviation, aperture

14. STATIC: All Error-Sources Before/after correction XT01 Trajectories X / Y, 100 seeds

15. XT01 DYNAMIC errors: dipole and quadrupole power ripple X distribution at the target (instability due to power ripple)  ≈ 0.5 mm 500 seeds

16. “Full (95%) beam sizes” = “spots” at XT01 target 500 seeds Required 3-4 mm beam spot X/Y. Factor 2 larger in both planes

17. Remaining acceptance N  (x/y) = [ APER(x/y) – X/Y(corr.+dynam.) ] / sqrt [ e_(x/y)*beta_(x/y) ]

18. Conclusions for 0.3 MeV/u Remaining aperture was estimated at about 2.5  for X and about 3.0  for XT01 Transmission is expected to be good (above 95% Stability at target is expected to be about 0.5 mm in X (1 sigma) Beam size at target is about 6-7 mm (95%) – May need collimation if this is too big. Experiments…? Still to estimate beam transmission using PTC track for both XT01 and XT02 Looks feasible for this mode of operation

19. Subsystems - diagnostics DB functional and mechanical specification finished Design fulfills requirements and is approved Market Survey document in preparation Prototype Faraday cup being tested at CERN Prototype DB being assembled at AVS – expected at CERN early October for tests Cabling needs defined and requests made Concern about electronics (acquisition and positioning) progress – working with BE/BI to define strategy Worries about alignment accuracy in Linac between SC modules – being investigated

20. Diagnostic box TYPE IV Collimator slit Type 2 FC Scanning slit Silicon detector Stripping foils

21. Subsystems - magnets Requirements, specifications purchasing strategy fully defined Magnetic measurements all to be done at CERN 22.5 deg dipoles: Coil orientation reversed. Refurbishment ongoing, electrical and magnetic measurements to do. Missing specification details for spare coils. 45 deg dipoles: Electrical, cooling and vacuum interfaces defined, magnetic design done, mechanical design and technical specifications ongoing, tendering end Oct. 12 Quadrupoles: Electrical and cooling interfaces done, vacuum and survey ongoing, magnetic design ongoing (steel selection critical), mechanical design and technical specification ongoing, tendering Nov. 12 Steerers: Design updated after CdR (water cooling), electrical, cooling and vacuum interfaces defined, magnetic design done, mechanical design being adapted to watercooled version, technical specifications started, tendering end Oct. 12

22. Magnets

23. Subsystems – power convertors All requirements finalised and technical solutions being defined FGC3s to be used for all control Quadrupole: – Industry. Current reversal needed for 4 units. Foreseen solution validated in tests and a draft specification is almost ready. The current looping control needs some more work. Steerer: – CERN design and assembly. MS deadline is set for October and tendering in December 2012. The first batch is then expected at CERN in December 2013. Second batch in 2015. Dipole: – CERN S250 design. Power converters to start production in 2014. SC solenoid: – LHC 600A/40V 4 Quadrants (LHC spare for Stage 1) Issues with power convertor rack placement….

24. Power convertors

25. Subsystems – supports and alignment Requirements fully defined Technical solutions defined No technical issue to meet required tolerance Detailed design in progress Cost estimates to refine Tendering planned for end October

26. Supports and alignment

27. Subsystems - vacuum Requirements fully defined and specifications documented Technical solutions defined – Sectorization in 4 vacuum sectors – Diagnostics by cold cathode gauges of pirani type and passive penning gauges on T-pieces – Turbo pumps (60 l/s) on diagnostic Boxes: ~1 every 2 DB – Protection of SC linac vacuum by fast valve + cryotrap (still needs calculations on effectiveness) Vacuum chamber and bellows detailed design in progress. – Vacuum system design ‘closed’ for HEBT – Issue with bellows and DB alignment in the inter-cryomodule region. SC module tolerances being discussed. Procurement fully in-house

28. Vacuum courtesy J.Bauche GSI magnets, Al chamber PRE-STUDY DIPOLESQUADRUPOLES

29. Subsystems - interlocking Requirements defined All documentation updated in detailed WP definition. Technical solution defined – Thermoswitches on all magnets, and some flow switches for dipoles. – PLC based as for other CERN WIC systems – Integration of switches on magnets/supports Cabling requirements defined and requests made Potential issue with the SC solenoids where the protection needs defining.

30. Interlocking Configuration DB Software “Beam Permit” ? Thermoswitch ELMWOOD Type 3106 – T117

31. Remaining issues/concerns Electronics for diagnostic boxes (acquisition and positioning). Resources and priorities. Tolerances for diagnostic boxes in inter-cryo module region – SC module flanges Cryotrap effectiveness for protection of SC cavities Budget constraints for procurement – need to be able to source all components in single order, for all phases… – Nota bene: we are assuming that we will NOT have the configuration with 5.5 MeV/u beams (2 SC modules) plus the UBEND beamline… Schedule still tight for end 2014 commissioning

32. Conclusion Positive outcome of Technical Design Review in July Good technical progress with designs of all systems Now well into the technical specification and tendering preparation phase No major schedule delays identified (yet) – should still be on track for commissioning end 2014 Some remaining concerns being addressed; no showstoppers identified (yet) Operation at 0.3 MeV/u looks feasible with the present equipment specifications and design Some re-focussing of the HEBT WG scope being discussed, to cover also beam dynamics through Linac. Not yet in place.