Neutrino Factory Design Overview and IDS-NF Status Michael S. Zisman* C enter for B eam P hysics

1. Neutrino Factory Design Overview and IDS-NF Status Michael S. Zisman* Center for Beam Physics Accelerator & Fusion Research Division Lawrence Berkeley National Laboratory (*with thanks to: S. Berg, K. Long, J. Pasternak, J. Pozimski, G. Prior, and C. Rogers) MAP Meeting–Jlab February 28, 2011 NF Report - Zisman

2. Outline • Introduction • Current baseline • IDR designs • IDR status • Progress since ISS • RDR goals • RDR tasks • RDR time scale • MAP contributions • RDR planning • Summary NF Report - Zisman

3. Introduction • Neutrino Factory design effort has been carried out internationally for ~5 years • International Scoping Study (“ISS”) • follow-on organization is International Design Study for a Neutrino Factory (“IDS-NF”) • European NF design effort managed and funded as part of EUROnu design study • EUROnu looking at 3 possible future neutrino facilities, along with corresponding detector options (WP5) • Superbeam (WP2), NF (WP3) and Beta Beam (WP4) • physics performance comparison of all three (WP6) • EUROnu WP3 is fully integrated with IDS-NF • Summary of main features follows NF Report - Zisman

4. Current Baseline (1) • Baseline has evolved since completion of ISS • mainly front-end optimization • primary “deliverables” unchanged • System descriptions (to follow) from IDR • http://www.hep.ph.ic.ac.uk/~longkr/tmp/IDS-NF_IDR/IDS-NF_IDR-D14.pdf • 129 authors (by my count) NF Report - Zisman

5. Current Baseline (2) • Schematic of IDR baseline shown here • brief descriptions of individual systems follow NF Report - Zisman

6. IDR Proton Driver • Proton driver defined only by performance specifications • several different implementations under study • ISIS upgrade [Thomason]; high-power SPL [Garoby], Project X [Gollwitzer] NF Report - Zisman

7. IDR Target • Target still Hg jet in 20 T solenoid • shielding for magnets found to be inadequate • too much heat deposited in coils • progress being made toward improved design • Fe plug (now eliminated) McDonald; Kirk; Graves NF Report - Zisman

8. IDR Front End (1) • Optimization to make shorter channel [Neuffer] • lattice parameters documented NF Report - Zisman

9. IDR Front End (2) • Drift length 111  80 m • Transport field 1.75 T  1.5 T • Buncher section 51 m  33 m (VRF = 9 MV) • Rotator 54 m  42 m (VRF = 12 MV) • Cooling section 75 m (VRF = 15 MV) [Rogers] ISS IDS-NF L = 80 m L = 120 m Issue of RF in a magnetic field remains NF Report - Zisman

10. Alternative Front Ends • Because of RF issue, several alternative approaches still being studied as backups • bucked coil lattice [A. Alekou] • magnetically-insulated lattice [D. Stratakis] • HPRF lattice [J. Gallardo, M. Zisman] Magnetically insulated lattice Bucked-coil lattice HPRF cavity lattice NF Report - Zisman

11. IDR Acceleration System • Multiple systems adopted • linac, RLAs, FFAG NF Report - Zisman

12. IDR Linac • Linac accelerates to 0.9 GeV [Bogacz] • three sections with increasing cell length NF Report - Zisman

13. IDR RLAs (1) • Two RLAs [Bogacz] • 0.9-3.6 GeV (0.6 GeV/pass) • 3.6-12.6 GeV (2 GeV/pass) RLA1 RLA2 NF Report - Zisman

14. IDR RLAs (2) • Optics developed to transmit both + and - in opposite directions • quad gradients increase linearly from linac center RLA2 linac RLA1 linac RLA1 ‘droplet’ arc NF Report - Zisman

15. IDR FFAG (1) • FFAG (12.6-25 GeV) [Berg] • linear non-scaling design NF Report - Zisman

16. IDR FFAG (2) • Ring uses combined-function Nb-Ti magnets • designs for both F and D magnets in progress • F magnet shown here; not yet optimized Iron yoke (field clamp) H. Witte NF Report - Zisman

17. IDR FFAG (3) • Scheme for injection and extraction has been developed [Pasternak, Kelliher] • requires lots of PFNs • and lots of power Injection Extraction NF Report - Zisman

18. IDR Decay Ring (1) • Unchanged since ISS Racetrack [Johnstone] Triangle [Prior, Rees] NF Report - Zisman

19. IDR Decay Ring (2) • Present baseline is racetrack design • more flexible • two independent sources that can be oriented as needed • can use either ring for both + and - • no ‘wasted’ beam if one ring or one detector unavailable • but, at a cost • two tunnels needed • four transfer lines to take full advantage of flexibility • and decent detector timing (~100 ns) • Triangle remains a viable alternative • two rings side-by-side in single tunnel • good detector timing mandatory with this geometry NF Report - Zisman

20. IDR Status • Original goals • develop complete (initial) NF accelerator design • produce initial cost estimate • Where we are • designs for most systems completed and lattices available • a few systems known to need work • E deposition in target region unacceptably high • no cost estimate is available • Leaders of this phase • Berg, Pozimski NF Report - Zisman

21. Progress Since ISS (1) • Initial concepts of FNAL, RAL proton drivers • Detailed E deposition studies in target area • Many front-end improvements • shorter phase rotation and bunching systems • assessed impact of reduced VRF in baseline • studied several alternatives as fallback options • particle loss estimates and mitigation strategy • Studied more complete RLA designs • symmetric gradient profile • chicanes for arc crossings • chromatic corrections in chicanes NF Report - Zisman

22. Progress Since ISS (2) • More realistic FFAG design • longer drifts • higher average gradient • inj/extr system design • initial magnet designs • Decay ring • studied diagnostics • polarimeter, angular divergence measurement NF Report - Zisman

23. RDR Goals • Complete description of all systems • Assessment of feasibility and performance • tracking (all systems, then end-to-end) • with imperfections • sufficient engineering to validate designs of “tricky bits” • cost estimate for entire facility • requires adequate level of design detail for engineering estimates NF Report - Zisman

24. RDR Tasks (1) • Overall • complete matching section designs to permit end-to-end simulations • complete engineering design of key components • issues are feasibility and cost • complete cost estimate • to be compared with EUROnu estimates for SB and BB • evaluate collective effects for all systems • Target • develop new solenoid and shielding configuration • define infrastructure NF Report - Zisman

25. RDR Tasks (2) • Front end • develop method for handling particle losses • finalize cooling configuration • issue of RF choice • Acceleration • confirm mechanical layouts • transfer lines, switchyards, bypasses, chicanes, arcs • finalize FFAG chromaticity correction scheme • track (with errors) through entire system • linac, RLAs, FFAG • evaluate cost of including FFAG vs. using only linac and RLAs NF Report - Zisman

26. RDR Tasks (3) • Decay ring • decide on chromaticity correction scheme • define injection scheme • evaluate need for beam abort system • define and design ring diagnostics NF Report - Zisman

27. RDR Time Scale • Time scale for all of this effort estimated (Berg) at 2 years • lack of engineering particularly critical • physics effort is also “thin” (and lots to do!) NF Report - Zisman

28. MAP Contributions (1) • MAP proposed these IDS-NF activities • proton driver (Project X version) • targetry and target stations • pion capture and muon phase rotation • ionization cooling • accelerator systems • site-specific (FNAL) underground engineering issues for the muon storage rings • overall coordination of effort for the low-energy NF option • participating in costing NF Report - Zisman

29. MAP Contributions (2) • More or less keeping up with physics effort • engineering effort is lacking • not obvious how to rectify this with projected budgets • Proposed activities predicated on reaching $15M per year • right now, we’re at $10M (for reasons beyond our control) • MICE magnet costs have risen dramatically and must be covered as the highest priority • leaves little “free energy” • We must revisit IDS-NF promises/schedule NF Report - Zisman

30. RDR Planning (1) • Still (more or less) following original roadmap NF Report - Zisman

31. RDR Planning (2) • IDR draft is complete and final comments and corrections being incorporated • includes physics case, accelerator description, and detector descriptions • Physics case still indicates NF is the most powerful tool for studying neutrino sector • finds continuum between single-baseline “LENF” and two-baseline IDS-NF configuration • depends on value of sin2 213 • which may well be known prior to making NF decision • Lower MIND threshold validated • progress made on defining near detector NF Report - Zisman

32. RDR Planning (3) • IDR will be reviewed by ECFA panel on May 5-6, 2011 (at Daresbury Lab) • after which IDR will be updated as deemed appropriate • then published on arXiv and as CERN Yellow Report • Ongoing discussion on whether to publish IDR in refereed journal • strong views on both sides • decision at next IDS-NF plenary meeting • October 17-19, 2011 at Virginia Tech • in any case, need to step up “community outreach” NF Report - Zisman

33. Summary • IDR design completed and documented • S. Berg and J. Pozimski editors of accelerator section • K. Long overall editor • Lattices for main elements documented • will facilitate subsequent end-to-end tracking • Review of IDR by ECFA panel scheduled for May 5-6, 2011 • Plans for reaching RDR being developed • K. Long and IDS-NF steering group • MAP resources for this task are limited NF Report - Zisman