Report on Fermilab Accelerator Advisory Committee Recommendations for Fermilab's Future

1. Report of theFermilab Accelerator Advisory Committeeon the Fermilab Steering Committee ReportOHEP Program Review of FermilabSeptember 25, 2007John CorlettCenter for Beam PhysicsLBNLChair of the Fermilab AAC

2. Fermilab Accelerator Advisory CommitteeAugust 8-10, 2007 Swapan Chattopadhyay (Cockroft Institute) John Corlett (LBNL, Chair) Gunther Geschonke (CERN) Georg Hoffstaetter (Cornell University) Kwang-Je Kim (ANL) Shin-ichi Kurokawa (KEK) Stephen Peggs (BNL) Tor Raubenheimer (SLAC) Hans Weise (DESY) Apologies from: Michiko Minty (BNL) Hasan Padamsee (Cornell University)

3. Agenda for the August 2007 AAC meeting Steering Committee Report (draft) Project X Muon Collider Task Force Crystal Collimation

4. Findings (1) • Draft Strategic Roadmap for accelerator-based HEP • Focus on facilities at Fermilab, in the context of the global particle physics program • Incorporates recommendations of EPP2010 NAS report & P5 • Goals to provide discovery opportunities over next 2-3 decades: • Active participation in LHC • Timely construction of the ILC is paramount • Supports R&D and engineering design for as early start as possible • Supports FNAL as potential host site • Maintain & develop a neutrino physics program leveraging existing infrastructure • Provide options for an accelerator-based experimental program in the event that ILC is delayed from the technically-limited schedule • Provide for pursuit of energy frontier colliders beyond reach of ILC

5. Findings (2) ILC scenarios • Scenarios 1-3 –– ILC is built in U.S. • Scenario 1: GDE baseline, decision in 2010, 2012 construction start • Scenario 2: GDE baseline + 2 years • Scenario 3: GDE baseline + 5 years • Scenario 4 –– ILC built outside U.S. or LHC shows a larger energy is required

6. Findings (3) Scenario 1 (ILC in ~GDE timeframe of 2012 start) • Fermilab priorities: • LHC physics • Leadership in the global ILC effort, goal of hosting at Fermilab • Neutrino program through with NOvA as flagship through ~2015

7. Findings (4) Scenarios 2&3 (ILC delayed from a technically limited schedule) • Fermilab priorities: • Scenario 1 plus • Extend neutrino and flavor physics capabilities by extending existing infrastructure • Modest delay –– SNuMI • Longer delay –– Project X • Interim project before ILC

8. Findings (5) Scenario 4 (ILC offshore, or higher energy shown to be needed) • Fermilab priorities: • Scenario 1 plus • Extend neutrino and flavor physics capabilities by extending existing infrastructure • Engage at a minimum in SNuMI • Project X if resources available and timing permits

9. Findings (6) In all scenariosthe report proposes that Fermilab: • Provide support of Project X R&D starting now and with emphasis on: • expediting R&D and industrialization of ILC cavities and cryomodules • overall design of Project X • Increase R&D for future accelerator options concentrating on neutrino factory and muon collider • Support detector R&D for effective use of future facilities

10. Comments on the Overall Plan • The committee strongly supports the plan presented • Provides options for the future of accelerator based high-energy physics at Fermilab • Has broad scope, addresses near and far-term activities • Physics program both at the Terascale in LHC and ILC energy frontier machines • Strong support for a timely start to ILC and hosting of the facility at Fermilab • Complementary intensity frontier physics based on high intensity proton sources • Variety of “off-ramps” dependent on ILC scenarios • A route toward the energy frontier beyond LHC and ILC • Critical for healthy future of HEP in the U.S.

11. Comments on Priorities The committee supports the (perceived) priorities: • Run-II, NOvA • LHC • ILC • Project X R&D • Muon Collider R&D • Core Fermilab commitments • Ongoing projects • HEP community priorities • Retain options for near and mid-term accelerator-based HEP in U.S. • Fermilab leadership in R&D • Collaboration with NFMCC and others, important to maintain longer-term options and capabilities

12. Comments on Project X (1) • The committee strongly supports plans for Project X • We congratulate the Project X team on an innovative design • 2+ MW proton source for neutrino & flavor physics • Integrate new ILC-like SCRF linac with existing infrastructure • Strong alignment with ILC needs • Also supports muon collider and neutrino factory development • A prudent backup plan in case of delay to the ILC • The committee encourages FNAL leadership to drive Project X forward • Project X needs to be ready with an engineering design in ~ 2010 • Maintain options for an experimental physics program in the U.S. • An immediate strong start is recommended • Preparations at the level of CD0 in 2008 • Note that DOE Critical Decision path may have strategic benefits (e.g. funding collaborators), but may not be essential to retaining options • We recommend that Fermilab be considerate of potential mis-interpretations of the priority of ILC with respect to Project X

13. Comments on Project X (2) • Front end of a H- linac is under development within HINS • The committee recommends that HINS be managed as part of Project X, and resources allocated accordingly • Prioritization • Components synergetic with the ILC • Cryomodule development as industrialization for ILC, and/or pre-production • Longest lead time items, such as understanding and mitigating difficulties in operating high currents in rings • Physics potential of Project-X should not be sacrificed • Cost from unnecessary similarity to ILC should be avoided • Example: Use of two tunnels does not appear to be warranted

14. Comments on Project X (3) • Project X requires operation of the Main Injector (MI) and Recycler Ring (RR) under conditions not yet demonstrated • Space-charge dynamics in the RR • Transition jump in the MI • Instabilities in both rings, including electron cloud • The committee recommends detailed studies to establish the viability of the RR and MI in supporting the proposed beam conditions • Including allocation of dedicated experimental beam physics time on the rings

15. Comments on the Muon Collider R&D Initiative (1) • The Committee welcomes the muon collider initiative and the formation of the Muon Collider Task Force • Long-range R&D toward a future energy frontier muon collider is important to pursue • An important step towards future lepton colliders in the TeV range • It is important that multiple options be available to the community • We endorse the statement in the report of the Steering Group • "In all scenarios ..... R&D for future accelerator options concentrating on the neutrino factory and muon collider should be increased" • The committee recommends that Fermilab takes a leading position in the global context of this long-range R&D

16. Comments on the Muon Collider R&D Initiative (2) • Time scale for the program is vague at the moment • R&D plans reach as far as 2024 • First statement about feasibility and cost ~2017 • In spite of the long lead time it is vital to advance with R&D now • Maintain a “critical mass” of effort to advance the most important technical issues • Earliest construction start in middle of the decade 2020 • A major issue is development of 6D muon cooling • We congratulate the team to their innovative and impressive work • Simulations of self-consistent 6-D cooling schemes are very promising • The proposed MANX experiment will be an important test of the Helical Cooling Channel (HCC) concept • Priorities • Demonstration of HCC concept • Development of high-gradient RF structures in strong fields • Support for High Temperature Superconductor development

17. Comments on Planning • The committee recognizes the early stage of current planning, and encourages development of resource-loaded schedules to allow planning in more detail • Include impact of Tevatron close end of FY09 • Integrated and realistic budget and schedules for the major FNAL programs • Including specialized staffing needs • For different scenarios

18. Comments on Collaborations • Resources to achieve the proposed goals will be limited • Look for collaborations and means to engage other facilities • Re-engage HINS collaborators in Project X at a more significant level • Expand collaborations to other institutions • Pursue DOE support for Project X • Engage wide community in muon collider R&D • Resources and priorities at Fermilab will not likely match the technically limited R&D plans • Coordination of national US and international efforts are starting, however, there is room for a broader participation in all aspects of muon collider R&D • Muons Inc. is a shining example of successful collaboration driving significant advances • The ambitious goals can probably only be met in a wide collaborative effort

19. Comments on Integration and Challenges • Integration of the Fermilab plan into the national plan needs to be developed and points clarified • e.g. involvement in CLIC is not a part of the Fermilab plan, but CLIC may have a role in the national HEP program • Other aspects of the National plan not highlighted in the Fermilab report • AARD, high gradient collaboration, ….. • Many unknowns, and challenges • FNAL leadership is encouraged to support a diverse range of activities to retain options for the future, while ensuring timely progress in projects of highest priorities in the physics community • Flexible approach/response • Drive support for R&D activities that maintain a range of options for accelerator based HEP in the future • The plan provides a strong base for the future of Fermilab

20. END Backup slides follow

21. Comments on Tevatron Based Facilities Beyond Run-II • Development of the existing infrastructure to enhance proton beam capabilities in support of neutrino and flavor physics • Use of the Tevatron for fixed target and test beam production • Good use of resources and investments made at Fermilab • Implementation will be determined by developments in the coming years • Options should be kept alive by maintaining infrastructure where possible

22. Developments from Proton Driver and High Intensity Neutrino Source • Project-X dramatically increases the high-energy proton power for neutrino experiments, and provides additional 8GeV beam • 2 MW, or even up to 2.5 MW • Rationale for a SRF linac still holds • Stacking in the Recycler allows the linac to operate with ILC beam parameters • 9 mA, 1 ms macro-pulse duration, 5 Hz repetition rate • Stacking in the Recycler Ring has advantages over the Main Injector • Stack in RR while ramping MI • Increased MI repetition rate • Additional 8 GeV proton beam is available from the RR • Proton energy is flexible at 2 MW • 40-120 GeV

23. Project X Linac and ILC Cryomodules • Project-X uses cryomodules close to the ILC design for ß above 0.6 • Needs 24 ILC, and 19 “ILC-like” cryomodules • Prepares and contributes to ILC industrialization and/or pre-series production • Production would satisfy the requirement of capability to produce 25 ILC cryomodules industrially per year • Differences to the ILC cryomodule • Different focusing requirements (number of quadrupoles) • Above 2.4 GeV, the cryomodules are as in the ILC. • For ß from 0.6 to 0.9, the cavities are operated in 8pi/9 mode • Needs lengthened cavities with slightly different mode structure • The committee recommends to study the impact of the π mode and other “undamped” modes.

24. RR High-intensity Effects and Extraction • Space-charge dynamics for the 2/3 filled Recycler • Relies on KV distribution • Has relatively large tune spread • Needs studies, including sensitivities and nonlinearities • Further analyze resonance extraction from Recycler

25. Project X Linac Upgrades • Potential upgrades presented • 3 times larger pulse currents • Up to 3 times longer pulse trains • Higher rep rate of the SRF linac • If such upgrades are desired, the cryomodule design has to be adjusted accordingly before construction

26. MANX Experimental Program • The 6D cooling ideas need experimental verification as soon as possible • MANX will be an important test of the Helical Cooling Channel • MANX is at an early stage, the deadline of February to formulate a proposal is challenging • Additional work is required to define tolerances on issues such as alignment, magnetic field quality etc, before a solid engineering design is possible • The beam measurement system needs to be defined in detail, and collaboration between accelerator and particle physicists in this area could be very productive • Presently two diagnostics systems are being studied • The Committee feels that single particle diagnostic techniques allow many aspects to be studied in a clear simplesystem

27. High Gradient Magnet Development • The Committee does not emphasize the development of high field solenoids as a priority • However, we strongly encourage Fermilab to support the enhancement of the national HTS conductor development program aimed at high field magnets • A high field HTS program should be developed in a collaboration among interested National Labs, Universities and HTS vendors