1. EVOLUTION OF BEAM CHARACTERISTICS DURING THE LIU PROJECT R. Garoby for the LIU Project Team March 7, 2012CERN

2. IntroductionIntroduction Action plan Expected proton beam characteristics In 2012 Between LS1 and LS2 After LS2 Summary

3. R.G. 3 LIU beam characteristics - 7/03/2012 Objectives Mandate “The LHC Injectors Upgrade should plan for delivering reliably to the LHC the beams required for reaching the goals of the HL- LHC. This includes LINAC4, the PS booster, the PS, the SPS, as well as the heavy ion chain.” Implementation The LIU Project will:  Analyze the status of the injectors and the HL-LHC requirements,  Propose an upgrade path for the injectors, exploiting the work done by the Task Forces on the „PSB energy upgrade“ and „SPS upgrade“ and by the Working Group on the SPS upgrade,  Organize the upgrades (WBS with resources and planning) and take care of their implementation,  Take care of hardware and beam commissioning.

4. R.G. 4 LIU beam characteristics - 7/03/2012 LIU-PSB coordination team K.Hanke – Activity leader B.Mikulec – Deputy V.Raginel – Scientific secretary https://espace.cern.ch /liu-project/liu-psb/ LIU- PS coordination team S.Gilardoni – Activity Leader H. Damerau– Deputy and Scientific secretary https://espace.cern.c h/liu-project/liu-ps/ LIU-SPS coordination team B.Goddard E.Shaposhnikova – Deputy G.Rumulo – Scientific secretary https://espace.cern.ch/ liu-project/liu- sps/default.aspx LIU-Project Safety coordination L. Ponce Director of Accelerators and technology - Steve Myers LIU Project team Roland Garoby (Project Leader) - Malika Meddahi (Deputy) - Brennan Goddard (LIU-SPS machine coordinator) - Simone Gilardoni (LIU-PS machine coordinator) - Klaus Hanke (LIU-PSB machine coordinator) - Maurizio Vretenar (Linac4 Project Leader)- Laurette Ponce (Project Safety Officer)-Django Manglunki (LIU-Ion chain coordinator) Linac4 Project M.Vretenar http://linac4- project.web.c ern.ch/linac4- project/ LIU Administrative Support: Cécile Noels. Project Support: Pierre Bonnal, Sylvain Weisz, Tadeusz Kurtyka - EVM coordinators: De Jonghe, Benoît Daudin Project Organization Breakdown Structure

5. Introduction Action planAction plan Expected proton beam characteristics In 2012 Between LS1 and LS2 After LS2 Summary

6. R.G. 6 LIU beam characteristics - 7/03/2012 To increase performance Brightness   Increase injection energy in the PSB from 50 to 160 MeV, Linac4 (160 MeV H - ) to replace Linac2 (50 MeV H + )  Increase injection energy in the PS from 1.4 to 2 GeV, increasing the field in the PSB magnets, replacing power supply and changing transfer equipment  Upgrade the PSB, PS and SPS to make them capable to accelerate and manipulate a higher brightness beam (feedbacks, cures against electron clouds, hardware modifications to reduce impedance…) To increase reliability and lifetime (until ~2030!) (tightly linked with consolidation)  Upgrade/replace ageing equipment (power supplies, magnets, RF…)  Improve radioprotection measures (shielding, ventilation…) Goals § Means

7. R.G. 7 LIU beam characteristics - 7/03/2012 PSB upgrades 160 MeV H - injection Doubling of density in transverse phase planes New RF system 2 GeV upgrade

8. R.G. 8 LIU beam characteristics - 7/03/2012 PS upgrade Increased transverse brightness 2 GeV injection Increased intensity / bunch Radioprotection

9. R.G. 9 LIU beam characteristics - 7/03/2012 SPS upgrade Increased transverse brightness Increased intensity

10. R.G. 10 LIU beam characteristics - 7/03/2012 Overall Plan Linac4PS injector, PS and SPSBeam characteristics at LHC injection 2011 - 2012 Continuation of construction… Beam studies § simulations Investigation of RCS option Hardware prototyping Test of new beam gymnastics Design § construction of equipment TDR 25 ns, 1.2 10 11 p/b, ~3 mm.mrad 50 ns, 1.7 10 11 p/b,  2 mm.mrad 2013 – 2014 (Long Shutdown 1) Linac4 beam commissioning Modifications and installation of some prototypes in PSB, PS and SPS Design § construction of equipment 2015 - 2017 Progressive increase of Linac4 beam current Implementation of new PS beam gymnastics… PSB modification and connection to Linac4 during extentended winter shutdown If/when Linac4 connected: progressive increase of PSB brightness with benefits for PS and SPS. Equipment design § construction for PSB, PS and SPS Beam studies Possibly smaller emittance (25 ns) with new PS beam gymnastics… Limited gain from Linac4 proper (pending PSB, PS and SPS hardware upgrades) 2018 (Long Shutdown 2) Extensive installations in PSB, PS and SPS Hardware commissioning 2019 –2021 Beam commissioningAfter ~1 year of operation: beam characteristics for HL-LHC…

11. R.G. 11 LIU beam characteristics - 7/03/2012 Timeline Length of LS2: minimum 12months (required by SPS 200 MHz) 2019 commissioning: several months 11 20122014201520162017 Linac 4 ready PSB-PS transfer 1.4 GeV  2 GeV PSB H - injection could be available 20132018 Chamonix 2012 SPS aC coating, 200 MHz power upgrade completed LS1 for injectors LS2 for injectors 2019 Injectors commissioned

12. Introduction Action plan Expected proton beam characteristicsExpected proton beam characteristics In 2012 In 2012 Between LS1 and LS2 After LS2 Summary

13. R.G. 13 LIU beam characteristics - 7/03/2012 Per bunch to LHC: horizontal scale depends on split-factor in PS PS RF manipu- lation scheme 25 ns bunch spacing 50 ns bunch spacing 1. Triple splittingN b /12Nb/6Nb/6 2. Batch comp. h9…h21Nb/8Nb/8Nb/4Nb/4 3. Batch comp. + merging + triple split Nb/6(Nb/4)Nb/6(Nb/4) Nb/3Nb/3 Intensity per bunch to SPS/LHC (no losses in PS/SPS): The smaller the splitting ratio the better, but Price to pay:  Shorter batches at PS extraction  Longer filling time + less bunches in LHC  l  1.1 eVs N b from PSB [10 10 ] Brightness and PS beam gymnastics H. Damerau – Chamonix2012

14. R.G. 14 LIU beam characteristics - 7/03/2012  Achieved performance  expected performance from assumptions  Insignificant gain expected from Linac4/PSB without 2 GeV upgrade Operational production scheme50 ns early 2011 25 ns ~nominal 50 ns CBI-limit PS injectionBunch intensity 0.8  10 12 ppb1.6  10 12 ppb1.2  10 12 ppb Emittance,  1.2  m2.4  m1.8  m Vert. tune spread,  Q y -0.24-0.26-0.25 PS ejectionBunch intensity 1.27  10 11 ppb 1.90  10 11 ppb Emittance,  1.3  m2.5  m1.9  m Bunches per batch367236 Brightness limit PSBXXX Space charge limit PSXXX Coupled-bunch limit PSX SPS ejectionBunch intensity 1.15  10 11 ppb 1.71  10 11 ppb Emittance,  1.4  m2.8  m2.1  m Relative intensity/luminosity in LHC0.67/0.671.33/0.671.0/1.0 Beam characteristics in 2012 H. Damerau – Chamonix2012

15. Introduction Action plan Expected proton beam characteristicsExpected proton beam characteristics In 2012 Between LS1 and LS2 Between LS1 and LS2 After LS2 Summary

16. R.G. 16 LIU beam characteristics - 7/03/2012 Main work on the accelerators during LS1 PSB: Construction of H - injection equipment (magnets, pulsers, vacuum chambers and valves…) Cabling for H - injection equipment Replacement of beam dump and crane Preparation for new main power converter (new building) Upgrade of beam instrumentation (new orbit measurement system and devices for H - injection) New LLRF and prototype RF cavity PS: Radiation shielding on Road Goward and above septum 16 Finemet-based longitudinal damper New beam instrumentation (fast BLMs, study of IPMs) Design/order of power converters for low energy correctors SPS: Preparation for upgrade of 200 MHz RF system Installation of aC coated vacuum chambers in 2-4 half-cells Upgrade of transverse damper Installation of wide band transverse feedback Beam instrumentation (BFCT upgrade, BGI development, new diamond BLMs, prototype mechanics for new wire scanner) Cabling! Cabling of fibre optic backbone and one LSS + some coaxial cables!

17. R.G. 17 LIU beam characteristics - 7/03/2012 Similar schemes as shown in Chamonix 2011; option for high-intensity LHC-type bunches: Several manipulations proposed to achieve very low emittance First MDs in 2012 Splittings on the flat-top not possible in 2012 due to hardware limitations  Decision on implementation Q4/2012  Could become operational for Q2/2014 25 ns50 ns Splitting ratio PS ejection/injection 63 Batch length from PS 3618 Pure h = 21 Pure h = 7 2.5 GeV   h = (7  8  ) 9 ...  14 7  21 15  16 ...  21 25 ns50 ns Splitting ratio PS ejection/injection 63 Batch length from PS 4824 25 ns50 ns Splitting ratio PS ejection/injection 4n/a Batch length from PS 32n/a   h = (7  8  ) 9 ...  14 7  21 15  16 ...  21 Pure h = 21 Pure h = 9 2.5 GeV Pure h = 21 Pure h = 9 2.5 GeV   h = (7  8  ) 9 ...  14 7  21 15  16 ...  21 Alternative beam gymnastics after LS1 H. Damerau – Chamonix2012

18. R.G. 18 LIU beam characteristics - 7/03/2012 First PS studies in 201250 ns high int. 25 ns low  x /  y 25 ns ultra-bright PS injectionBunch intensity 0.6  10 12 ppb 0.8  10 12 ppb0.65  10 12 ppb Emittance,  1.0  m1.2  m1.0  m Vert. tune spread,  Q y -0.21-0.24/-0.26-0.26 PS ejectionBunch intensity 1.90  10 11 ppb1.27  10 11 ppb1.54  10 11 ppb Emittance,  1.1  m1.3  m1.1  m Bunches per batch18/2436/4832 Brightness limit PSBXX/-X Space charge limit PS-/XX Coupled-bunch limit PSX SPS ejectionBunch intensity Beyond SPS reach 1.15  10 11 ppb Beyond SPS reach Emittance,  1.4  m Relative intensity/luminosity in LHC(1.0/1.8)1.3/1.3(1.63/2.38) 30% higher than today with 50 ns Potential beam characteristics after LS1 H. Damerau – Chamonix2012

19. R.G. 19 LIU beam characteristics - 7/03/2012 More injections into SPS to recover from shorter PS batches PS RF manipulationTransfers PS-SPS# bunches in LHCMin. fill time Triple splitting 2/3/4  72 bunches 28081.08 min 38 s h = 9  10  20  21up to 4  64 bunches 26880.96~ 9 min 20 s h = 7...14  7  21up to 7  36 bunches 25200.90~ 13 min h = 9...14  7  212/4/5(/6)  48 bunches 25920.9210 min 5 s h = 9...21 (pure batch comp.) up to 8  32 bunches ~2450~0.87~14 min 20 s 2011 performance on flat-top achieved during MD with Q20 optics  Further optimization?  Multi-bunch limit?  MDs in 2012 to explore Q20 optics, single bunch H. Bartosik horizontal vertical Brightness in SPS and LHC filling schemes H. Damerau – Chamonix2012

20. Introduction Action plan Expected proton beam characteristicsExpected proton beam characteristics In 2012 Between LS1 and LS2 After LS2 After LS2 Summary

21. R.G. 21 LIU beam characteristics - 7/03/2012 Basic assumptions  Beam parameters are given at injection in LHC: beam loss and blow-up inside the LHC are not accounted for.  All necessary improvements are implemented in the injectors (Linac4, PSB to PS transfer at 2 GeV, coupled bunch instabilities suppressed, e- cloud suppressed, hardware upgraded…)  Estimated beam degradation in the accelerator chain (based on observations in 2010): PS: 5 % beam loss, 5 % transverse blow-up SPS: 10 % beam loss, 10 % transverse blow-up.  «Standard» RF gymnastics are kept, imperfections are unchanged: +-10 % fluctuation of all bunch parameters within a given PS bunch train. Traces of ghost/satellite bunches.

22. R.G. 22 LIU beam characteristics - 7/03/2012 Limit is 2.3 10 11 p+/b in 3.6 um at SPS extraction (1.6 10 11 in 2.3 um) Limited* by space charge in PS 25 ns after LIU upgrade B. Goddard – Chamonix2012 Batch compression might bridge the gap… *Core subject of investigation

23. R.G. 23 LIU beam characteristics - 7/03/2012 50 ns after LIU upgrade Limit is 2.7 10 11 p+/b in 2.7 um at SPS extraction Limited* by longitudinal instabilities in PS and SPS, and by brightness in SPS B. Goddard – Chamonix2012 *Core subjects of investigation

24. R.G. 24 LIU beam characteristics - 7/03/2012 25 ns Ib [10 11 ]Exy [um] Relative luminosity with ideal Xmission in LHC(prop. to Ib 2 /Exy) HL-LHC target (LHC flat-top)2.02.51.00 LIU scenario (SPS extraction) LIU baseline (>LS2)2.33.60.92 + "stretch" blowup/losses (>LS3)2.33.31.00 + PS  Q to -0.32, PSB DQ to -0.31 (>LS3) 2.12.31.20 50 ns Ib [10 11 ]Exy [um] Relative luminosity with ideal Xmission in LHC (prop. to Ib 2 /Exy) HL-LHC target (LHC flat-top)3.33.01.00 LIU scenario (SPS extraction) LIU baseline (>LS2)2.7 0.74 + "stretch" blowup/losses (>LS3)2.82.50.86 + PS longitudinal stability 3.7e11 (>LS3)3.43.21.00 + SPS  Q to -0.17 (>LS3) 3.42.81.14 Let’s dream… Batch compression might bridge the gap… 2.3 1.4 B. Goddard – Chamonix2012

25. R.G. 25 LIU beam characteristics - 7/03/2012 Impact on other users of proton beams  The LIU project is designed to have no detrimental effect on other users than LHC.  However:  New beam gymnastics in the PS will decrease the availability of the injectors for non-LHC users,  Many actions will increase performance /pulse (Potential for e.g higher beam energy/higher beam power to ISOLDE, higher intensity per pulse in the PS and SPS...)  Specific analysis will be required for every user to determine how much performance could progress beyond today’s level. In the case of neutrino beams, for example, such an analysis is foreseen in the context of the LAGUNA-LBNO.

26. Introduction Action plan Expected proton beam characteristics In 2012 Between LS1 and LS2 After LS2 SummarySummary

27. R.G. 27 LIU beam characteristics - 7/03/2012 H/V transverse emittances [mm.mrad] Bunch intensity within constant longitudinal emittance [x10 11 p/b] Nominal performance Today (2012) Beam parameters at LHC injection [25 ns] HL-LHC requirement at 7 TeV SPS single bunch limit Anticipated performance after LIU After LS1 (with batch compression) …

28. R.G. 28 LIU beam characteristics - 7/03/2012 H/V transverse emittances [mm.mrad] Bunch intensity within constant longitudinal emittance [x10 11 p/b] Nominal performance Today (2011) Beam parameters at LHC injection [50 ns] HL-LHC requirement at 7 TeV SPS single bunch limit After LS1… Anticipated performance after LIU

29. R.G. 29 LIU beam characteristics - 7/03/2012 Final comments about proton beams  Preliminary HL-LHC requirements are very demanding for the injectors. Their final definition shall result from interactions between both projects (2 nd joint «Brainstorming» session on March 30, 2012).  MDs until the end of 2012 will help refine the knowledge and understanding of the injectors and specify precisely the upgrades.  End 2012/beginning 2013, the performance goals of the LIU project will be specified and the precise list of hardware modifications with their specifications will be issued.

30. R.G. 30 LIU beam characteristics - 7/03/2012 Comments about other ion beams  With the present injector complex, increasing the number of bunches seems to be the only route to a marginally higher luminosity, at the expense of a longer LHC filling time,  If we are to implement the suggested improvements in order to reach the required Pb-Pb luminosity (provided the LHC can digest it), it is more than time to start the R§D on all parts of the injector chain,  Ar and Xe will be available after LS1 (parameter list still to be defined and optimised) but other species, if desired, would come in addition, and require more studies, in particular a new source & pre-accelerator for deuterons, or safety and handling issues for Uranium. D. Manglunki – Chamonix2012