AAC Closeout Report

1. AAC Closeout Report Fermilab Accelerator Advisory Committee Meeting July 28-30, 2010

2. AAC Committee • Members present E. Colby (SLAC), R. Garoby (CERN), S. Gourlay (LBNL), K. Harkay (ANL, chair), A. Hutton (Jlab), K. Oide (KEK), P. Ostroumov (ANL), A. Seryi (SLAC) • Guest members M. Blaskiewicz (BNL), F. Willeke (BNL) • Excused I. Ben-Zvi, L. Merminga, J. Rosenzweig • Outline/subcommittees Overview: K. Harkay Post Run-II: F. Willeke (lead), M. Blaskiewicz, K. Oide AARD: A. Seryi (lead), S. Gourlay, E. Colby PX and MC: R. Garoby (lead), P. Ostroumov, A. Hutton

3. Overview • We were asked to comment on three areas: • Goals and plans for a post-run II study period • Opportunities for an Advanced Accelerator R&D (AARD) program at the NML facility; also proposal for A0. • Concept for evolving Project X into a muon collider front end • All three areas are in a relatively early stage of development and/or planning • Enthusiastic community support for accelerator physics studies for Tevatron end-of-run and for proposed accelerator physics experimental facilities at NML and A0. • The eventual development of a muon-based facility (neutrino factory or muon collider) is an important long-term goal at FNAL. Issue is upgradability of ICD-2 to 4 MW.

4. Overview comments relating to charge • Observations and recommendations relating to questions in the charge are summarized on the following slides • More details in presentations by Subcommittee Leads

5. Post Run II Goals Are the goals of the study period well defined? • Observations • Committee strongly supports overall goal to use Tevatron as a test bed • Enthusiastic community response at Jan workshop • Individual study requests range from well-defined to more unrealistic in terms of resources • The studies list has not been prioritized

6. Post Run II Proposals What aspects of the proposal are most compelling in terms of advancing the world’s knowledge of the accelerator physics phenomena in high energy proton colliders? providing information required to maximize performance of the LHC over the upcoming decade? • Observations • Collimation clearly a top priority for both reasons • Merits of other proposals discussed in following talk • Recommendations • Disseminate knowledge through documentation of results – make this a condition • Opportunity to establish an ongoing Hadron Collider Physics collaboration

7. Post Run II Studies Plan Is the accompanying studies plan/schedule well-structured to achieve the goals outlined? • Observations • A studies list was presented and the requested number of shifts was given for some of these • Need to prioritize – not all requests can be accommodated. Estimate about 6 weeks of studies available over a few-month period. • Need to decide which studies can be done at ends of stores and which need dedicated blocks of time • Recommendations • Identify a Studies Coordinator and a process by which priorities are established and scheduling decisions are made. Balance desire to be flexible with maintaining a focused program. • Formalize planning process by creating a Task Force for each topic to discuss feasibility, requirements, and other details

8. AARD at NML Identify those elements of the potential program that hold the highest scientific interest within both a national and international context. • Observations • NML a unique opportunity for accelerator physics R&D and national/international collaboration; considerable interest from community • Need to balance goals between ILC and AARD users. Clear expectations should be communicated to users of ILC priorities. • Little discussion of use of NML for Project X SRF studies or to follow up on beam dynamics studies at FLASH • Recommendations • Exploit FNAL’s strengths in choosing experiments and tie them to unique NML parameters for greatest impact • Details to be addressed in following talk

9. NML Unique Capabilities Identify those characteristics of the NML facility that are unique, and suggest how those characteristics might best be capitalized on. • Observations • Unique features: bunch charge & time structure, phase space manipulation, high compression, focused beam • Recommendations • Plan AARD program that recognizes the commitment to ILC • Need to determine the User Support model; clear definition of how user experiments are integrated • Enhance, engage community in planning; establish policies for balancing user requirements with ILC commitments

10. AARD Proposal Any further suggestions on the development of a competitive proposal are appreciated. • Recommendations • Science case needs to be better articulated, selecting 2-3 headline experiments that are tied to unique NML parameters • Emphasize education • Establish a Program Panel that selects the high-priority, unique experiments • Connect this program panel with AAC and also with panels for other advanced accelerator R&D facilities • Further development of ideas for using compact storage ring is encouraged

11. Source Develop. Lab at A0 How compelling and timely are the scientific objectives? • Observations • Student education, operator training, non-accelerator applications • Good opportunity to use A0 infrastructure and hardware to continue a more modest R&D effort • Local academic institutions support proposal scientifically, opportunity to more closely involve Argonne • Synergy with Fermilab in-house electron expertise • Detailed discussion of individual proposals in following talk

12. Source Develop. Lab at A0 (cont) How credible is the plan for achieving the objectives? What are the opportunities for development of the facility beyond initial objectives? • Observations • Plans for support do not appear to be sufficient. Not clear what is FNAL level of commitment. • Scientific merit of installing both L-band and S-band systems is unclear and could dilute limited resources. • Recommendations • Establish FNAL supervision to ensure that program remains relevant and connected to NML/AARD, also to ensure that safety is well structured. Ensure that FNAL support is above the critical mass. • Establish collaborations with other labs in the area of cathode R&D to best leverage efforts (growth, characterization infrastructure) • Exploit access to Cs2Te deposition chamber for R&D

13. Project X as MC front end Have the fundamental physics/technical issues that need to be overcome to utilize Project X as a muon front end been identified? • Observations • Charge-exchange injection, microwave instability, and bunch compression issues in the ICD-2 and a particular 4-MW configuration were presented. • Carbon foil injection possible with a pulsed 0-8 GeV linac and laser stripping required for CW linac. Liquid Li stripper idea was rejected, but it may be able to handle higher beam power, e.g. 50 mA. • Bunch compression scheme still needs a lot of work. Fast vs. slow injection vs. lifetime in accumulator still open questions.

14. PX as MC front end (cont) What is the level of understanding relative to translating these issues into performance requirements for Project X, either in its initial or upgraded configuration? • Directions are unclear, not a design; technical issues to be demonstrated Do the general concepts outlined lead one to conclude that an upgrade path should, in principle, exist? • Project X ICD-2 is not directly compatible with muon collider without major impact, but provides an opportunity to contribute towards the feasibility of a future muon facility. • Suggest a strategy for how to evolve PX • A future muon facility (NF/MC) should be at FNAL • Think about staging PX to demonstrate feasibility for scaling up to 4 MW

15. Project X planning for CD0/CD1 Does the program of study proposed provide confidence that such an upgrade path, and corresponding requirements on Project X, could be established over the next two years? • PX should be optimized as soon as possible, to get CD0 as quickly as possible. Focus on the most important near-term goal of LBNE and rare decays program. • Recommendations • RCS and pulsed linac for 3-8 GeV comparable in costs; pulsed linac provides several opportunities without compromising Project X near-term goals • Study H- injection at 8 GeV • Better upgradeable to higher energy if needed. Tunnel should be designed for high power; RF power and couplers would have to be upgraded.

16. Summary • FNAL has a unique opportunity to engage in accelerator physics R&D in the post-run II study period and at the NML. • A more formalized planning process is recommended to both engage users and to ensure a successful, focused program. • Source Development Lab proposal at A0 has good scientific potential given an adequate level of FNAL commitment. • Project X should be optimized for near-term goals as soon as possible. • Project X ICD-2 is not directly compatible with muon collider without major impact, but can contribute towards the feasibility of a future muon facility. Pulsed 8-GeV linac option offers several advantages. • Committee thanks the FNAL directorate for its hospitality during this review.