Muon Campus Beam Transport January 23, 2013 J. Morgan

1. Muon Campus Beam Transport January 23, 2013 J. Morgan

2. What we have now – the Pbar source J. Morgan

3. Recycler Ring The Muon Campus P1 - P2 - M1 M3 Delivery Ring AP-50 MI-8 Line AP-30 AP-10 Muon Campus R. Ray - Director's CD-1 Review R. Ray - Mu2e Collaboration Meeting J. Morgan

4. Antiproton Source Beam lines • A 120 GeV/c proton beam is transported to the Target Station via AP-1 every 2.2 seconds • An 8.89 GeV/c negative secondary beam travels down AP-2 and is injected into the Debuncher • 8.89 GeV/c antiprotons are bunch rotated and stochastically cooled in the Debuncher, then transferred to the Accumulator via the D/A line • Antiprotons are accumulated over hours, then transferred to MI via the AP-3 and AP-1 lines • 8.89 GeV/c protons can be “reverse injected” or sent in the reciprocal direction of the antiprotons for tune-up J. Morgan

5. Muon Campus Configuration • The Accumulator and D/A line are no longer needed and will be used for beamline components • M1 is the new name for AP-1, apertures will be improved to accommodate the larger 8.89 GeV/c primary beam • AP-2 will be renamed M2 and will be a dedicated beam line for g-2 • The M3 line will connect to the Delivery Ring (Debuncher) in the D30 straight section • Both the g-2 secondary beam and Mu2e proton beam will be transported to the Ring via M3 • M2 and M3 will have a higher quadrupole density than AP-2 did (~4.4 m vs. ~13.0 m) for g-2 • Extraction, both single turn for g-2 and resonant for Mu2e, are also in the D30 straight section • The old injection region for AP-2 will become an abort for Mu2e and could be used for proton removal for g-2 • The new extraction line will be called M4 • The g-2 line connects M4 to the g-2 Storage Ring J. Morgan

6. Repurposing Pbar Antiproton production Muon Campus J. Morgan

7. Challenges and Technical Risks • High intensity 8 GeV proton beam in M1 (and M3 for Mu2e) • Much larger beam size in beamlines upstream of AP0 • Beam loss must be kept extremely low • Much higher intensity for Mu2e in Rings enclosure • Bunch formation takes place in Recycler • Incoming beam has increased momentum spread • Average cycle time is much faster than for Pbar • Factor of 13 for Mu2e, 26 for g-2 • New kicker power supplies needed • Pulsed septum based on Booster BSE • AP-3 beam line will be reconfigured for compatibility with g-2 • Secondary beam line for g-2 (M2) connects to M3 • g-2 requires dense quadrupole spacing to minimize beta functions • Old upstream AP-3 lattice must be matched to downstream M3 lattice for Mu2e • Beam is injected and extracted into the Delivery (Debuncher) Ring in D30 • New M3 to Delivery Ring connection faces logistical challenges • g-2 fast extraction as well as Mu2e resonant extraction must be supported • Mu2e will require substantial radiation shielding for injection and extraction devices • M4 line must transport both Mu2e and g-2 beams to their experimental halls Delivery Ring Future injection region J. Morgan

8. Muon g-2 Beam lines • The P1, P2 and M1 lines will transport an 8.89 GeV/c proton bunch, 120 ns long, to the Target Station at an average rate of 12 Hz, with 100 Hz bursts (16 bunches, 10 ms interval) • Downstream of the Target Station, the M2 line will carry the 3.1 GeV/c secondary beam 150 m until it connects with M3 • Some of the pions decay into 3.09 GeV/c muons as they travel down M2/M3 • The M2 and M3 lines have an increased quadrupole density to improve muon yield • The M3 line connects to the Delivery Ring after an additional 130 m and is injected in the 30 straight section • Muons can circle the 505 meter Delivery Ring as many times as desired • The abort located in the 50 straight section can be used to remove protons (requires multiple turns) • 3.09 GeV/c muons are extracted into the M4 line, then bent into the g-2 line for transport to the Storage Ring in the MC-1 building Target Station J. Morgan

9. Mu2e Beam lines • An 8.89 GeV/c proton bunch, 120 ns long, is transported to the Delivery Ring via M1 and M3 (bypassing the Target Station) at an average rate of 6 Hz with 18 Hz bursts • The 8.89 GeV/c bunch is injected into the Delivery Ring in the 30 straight section with a pulsed septum and kicker • A 2.5 MHz RF system maintains the short bunch as it circulates in the Delivery Ring • The proton bunch is resonantly extracted with electrostatic septa and a Lambertson into the M4 line • The M4 line transports short proton “micro-bunches” to an external Target Station to produce an intense muon beam • The remaining proton beam that is not resonantly extracted is aborted in the 50 straight section and transported to the abort dump J. Morgan

10. Possible Beamline Project Responsibility J. Morgan

11. 8 GeV protons to the Target Station • RR to P1 stub line optics has been being integrated into entire line • Needed to reconcile different MAD and OPTIM files • Optimization of optics underway to reduce beam size through lines • Magnet choices for aperture improvements has been refined • Surplus Tevatron B2 magnets will be used at V714 • Lower beam momentum for g-2 allows the use of weaker and/or shorter magnets in M1, but will limit the peak beam energy to about 40 GeV • A CDA Cooling Ring dipole will be used at F-17 in place of the C-magnets • Pbar MDC magnets will be used in the HV100 and HV102 bend strings • Smaller aperture trims will be replaced with Pbar NDA and NDB trims • Beam spot size specification has been reduced • Spot size requirements has been reduced from σxy = 0.55 mm to 0.15 mm • Final Focus region will incorporate a quadrupole triplet • Final 3Q120 quadrupole will be replaced by three Pbar SQx quads • Triplet configuration will greatly reduce the peak β functions in the M1 line • SQx quadrupoles will have a large enough aperture for high efficiency transmission and small spot size at the Target • Instrumentation • Existing BPM, Toroid and SEM/Multiwire systems can be used with minimal modification • Tevatron BLM electronics will be repurposed to upgrade legacy equipment J. Morgan

12. RR to Target MAD file Meiqin Xiao Jim Budlong J. Morgan

13. 120 GeV Pbar production MI to Target Station 8 GeV Muon production RR to Target Station

14. Planned improvements HV100 dipoles MI-52 Lam. / V701 C-magnets Tev. F0 Lambertsons removed Larger trims V714 C-magnets F-17 C-Magnets HV102 dipoles Quad triplet J. Morgan

15. Final focus region in M1 SQx triplet Vault Wall ValeriLebedev J. Morgan

16. Injection lines to Delivery Ring – M2 & M3 • Target Station to M3 line (M2) • Four magnet quadrupole “triplet” remains at beginning of line • β functions peak around 80 - 100 m in IQ2 and IQ3 (limiting aperture) • Junction between lines is located 100 – 125 m from Target Vault wall • 4.4 m Quadrupole spacing with 90 phase advance • Power supply requirements and magnet busing yet to be done • M2 to M3 connection • Original optics plan required the removal of a 20 ton dipole magnet in Right Bends to switch between g-2 and Mu2e • Present design does not require magnet removal, but has six dipole magnets which adds considerable cost • Power supply requirements and magnet busing yet to be done • M3 line to Delivery Ring • Challenging design constraints to match optics and trajectory into Ring • Optics design has two elevation changes and a 5 horizontal bend • Confined area for magnet supports in area over Delivery Ring • Need >30 inches between Delivery Ring and M3 to allow use of existing pbar magnets • Must be compatible with injection scheme into Delivery Ring • Optics must match and acceptance must be at least 40 pi-mm-mr for g-2 • Power supply requirements and magnet busing yet to be done • Instrumentation • g-2 will use upgraded SEM’s and new ion chambers, possibly wall current monitors • Mu2e will use existing BPM and SEM systems, plus upgraded toroid electronics J. Morgan

17. Target Station to Delivery Ring (g-2)AP-2 removed and replaced by M2 line,which connects to M3 line M2 18.5o Bend M3 M2→M3 IQ07 → IQ13 RemainIn Situ ~13.33m separation John Johnstone J. Morgan

18. M2 to M3 Line Cross-over Mod B1 “Switch” 5’ somethings C-mag SDE M3 SDE g-2 beam offset ~3.75” M2 John Johnstone J. Morgan

19. M2 to M3 Line Cross-overalternative scheme John Johnstone J. Morgan

20. M3 line into Delivery Ring John Johnstone Continuation of earlier slide J. Morgan

21. Mu2e beam pathto Delivery Ring • M3 line will branch from M1 (AP-1) line and bypass Target Station as AP-3 line does now • M3 line between the Target Station bypass and the M2/M3 line merge needs to be reconfigured to match new downstream lattice (140 m), has not been done yet • M3 line downstream of M2/M3 line merge must have optics designed to accommodate both g-2 and Mu2e beams • High intensity 8.89 GeV/c protons instead of 3.1 GeV/c secondary beam, radiation shielding will be required at loss points under service buildings Target Station bypass J. Morgan

22. Delivery Ring • Injection from M3 line • All injection bends are vertical – mature design completed • Modified Main Injector C-Magnet for initial bend • Injected beam passes through Pbar LQ magnet ~130 mm above centerline • Modified Booster septum magnet provides the greatest bend • Two module injection kicker system puts beam on D.R. closed orbit • Injection scheme preserves 40 pi-mm-mr acceptance or greater • Is also compatible with Mu2e 8.89 GeV/c protons, except optics match not done • 30 straight section reconfiguration • Cable trays must be relocated to provide room for new beamlines and radiation shielding • Most Delivery Ring magnets will need to be temporarily removed to facilitate beamline installation • Logistics are very challenging, work is very time-intensive and involves outside labor • Mu2e Abort and g-2 Proton Removal • Shared system in the 50 straight section (old AP-2 injection) • Multiple D.R. revolutions required to adequately separate protons from muons • Extraction to M4 line • Lambertson magnet required to accommodate Mu2e resonant extraction • Either modified NOvA design (MLAW) or new design • 8Q32 quadrupole (from BNL?) at D2Q5 • C-Magnet follows quadrupole, identical to what will be used for injection • Dual kicker schemes for both dedicated g-2 running and Mu2e/g-2 running J. Morgan

23. Delivery Ring Lattice 30 straight section Mu2e lattice g-2/Pbar Debuncher lattice J. Morgan

24. Delivery Ring Instrumentation • Mu2e • Existing BPMs pick-ups will be reused • Electronics from both Tevatron and Recycler Ring will be repurposed • Existing DCCT will be used with minor modifications • Tevatron BLM ion chambers and electronics will be repurposed • Existing SEMs will be located in straight sections • g-2 • New Wall Current Monitors • Pbar BLM’s will be repurposed • Would like to use same cables as Mu2e BLM’s to save money • Existing SEMs will be located in straight sections Brian Drendel Tevatron BLM Pbar ion chamber J. Morgan

25. D30, AP-3 line Crossover area D30, AP-3 line above Debuncher, D3Q6 on left Injection line layout – horizontal bend in D30 J. Morgan

26. Delivery Ring Kickers • Reuse existing Debuncher kicker magnets • Reduced cost and labor effort • Best combination of size and strength • Power supplies can’t be reused due to fast cycle time • Kickers rise and fall times do not need to be particularly fast • Single 120 ns bunch in Delivery Ring • 450 ns rise and fall times typical for three kicker magnets in series • Single power supply can power magnets in series • Keep power supply costs as low as possible • Limited space available in service buildings • Two Fluorinert skids in AP-30 and AP-50 • AP-30 system can be shared by injection and extraction kickers • May be possible to use single AP-30 system to save costs • Magnet loads located in service buildings to avoid radiation problems • Power supplies based on NOvA design • May be able to reuse some RG-220 cable, PFN spools J. Morgan

27. Kicker locations and rates Extraction kicker Pbar extraction kickers Abort/proton removal kicker Injection kicker J. Morgan

28. Kicker rise and fall times J. Morgan

29. Injection Region Bend angles of Septum, LQ and C-Magnet Injection region John Johnstone – M3 line optics J. Morgan

30. g-2 vertical injection trajectory (with and without vertical bump) J. Morgan

31. Mu2e vertical injection trajectory J. Morgan

32. Delivery Ring Mu2e Abort(repurposing and shared-use) • Former downstream section of AP-2 used for abort line • Abort absorber located in Transport tunnel (using existing E760 collimator) • Relatively low beam power (0.40 kW – designed for 5% of 8 kW beam power) so cooling water system is not needed • Requires one new Vertical bending magnet and trims J. Morgan

33. Proton Removal for g-2 • Target Station to Delivery Ring distance will be about 290 meters • Muon and proton centroids separate by about 40 ns • Injection kickers and abort at D4Q5 is 352 meters (50 ns) • Delivery Ring circumference is 505 meters • Muon and proton centroids separate by about 70 ns per turn • Bunch length is about 120 ns (possibly with satellites) • Centroid separation to abort on first turn is 91 ns, second turn 161 ns, etc. • Mu2e abort can be used for g-2 proton removal • Multiple turns required to create a large enough gap between protons and muons • Mu2e abort has a 450 ns rise time “as is” • Mu2e has a 120 ns bunch length, Delivery Ring revolution period is ~ 1,700 ns • Around 7 turns in the Delivery Ring to remove protons completely • 6 turns to eliminate 90% of protons without disturbing muons • Existing kickers could rise in 200 ns with a power supply upgrade • Around 5 turns in the Delivery Ring to remove protons completely • Would require 2 power supplies operating in parallel instead of 1, at a cost of about 700 k$ • “Straight through” distance to g-2 is about 425 meters • 90% of the pions will decay “straight through”, >99% after one turn in Delivery Ring J. Morgan

34. Protons slipping in time Drawing by T. Leveling J. Morgan

35. Delivery Ring Extraction • Extraction layout is driven by resonantly extracted beam for Mu2e • Electrostatic septa surrounding D2Q3 bend beam horizontally ~1 mr each • Mu2e resonantly extracted protons have much smaller emittance than g-2 muons • Lambertson is required for Mu2e to work with electrostatic septa • A large aperture quadrupole is required at D2Q5, larger than Pbar LQx • An 8Q32 quadrupole and C-Magnet both provide additional vertical bends • Mu2e has Delivery Ring optics that are unfavorable for maximizing g-2 Ring acceptance • Different optics and different horizontal trajectories are needed for g-2 and Mu2e • A large horizontal bump across the extraction region is used for g-2 • g-2 needs an extraction kicker for beam to enter the M4 line • Best location for kickers is where Mu2e septa will eventually reside • A two kicker system will be used for g-2 dedicated running • Existing Pbar kickers can be used as-is • Two kicker layouts are planned for g-2 dedicated running vs. “dual mode” • For dual mode, a single module can be used(a benefit of the 3.09 GeV/c momentum) with a altered impedance to increase strength • Extraction scheme provides 40 pi-mm-mr acceptance for g-2 and a common extraction channel for both experiments J. Morgan

36. g-2 extraction trajectories Horizontal bump across extraction region (note different scales) Bump created by motorized quadrupoles at 203, 204, 206 and 207 J. Morgan

37. Mu2e extraction trajectory (horizontal bump removed) J. Morgan

38. Extraction kicker layouts g-2 operation and Mu2e beamline commissioning (uses Pbar EKIK modules with 12.5Ω impedance) Dual mode – either g-2 or Mu2e can run (uses Pbar IKIK modules with 8.33Ωimpedance) J. Morgan

39. Extraction kickers Injection kickers Horizontal bend (5) Vertical bend Extraction Lambertson and C-magnet Injection Septum and C-magnet Vertical bends g-2 operation and Mu2e commissioning

40. Extraction septa (Mu2e) Extraction kicker (g-2) Injection kickers Horizontal bend (5) Vertical bend Extraction Lambertson and C-magnet Injection Septum and C-magnet Vertical bends Dual running mode configuration

41. Extraction Region Bend angles of Lambertson, LQ and C-Magnet 8Q32 40 pi-mm-mr beam envelopes Extraction region Carol Johnstone – M4 line optics J. Morgan

42. Extraction beamlines (M4 and g-2) • M4 Line • First 20 m of line must fit above Delivery Ring, requiring at least 30” separation • Elevation change to 48” above Delivery Ring is completed before Left Bend • Location of Left Bend is critical to location of MC-1 (g-2) and Mu2e buildings • MC-1 building is highly constrained by road and utility corridors • Mu2e building also constrained to east and north (wetlands) • Process of eliminating mechanical conflicts and using available pbar magnets of known designs has shifted bend downstream from what was shown for Mu2e CD-1 Review • Left Bend dipole configuration has been changed to increase total bend to ~40° • Original concept of “split” between M4 and g-2 now more difficult to design • M4 line from Left Bend to Mu2e must incorporate several features • Extinction • Diagnostic dump • Final Focus, 2.4° downward slope and 2 foot elevation change to target • Has not been demonstrated that 40 pi-mm-mr acceptance will be preserved for g-2 • Instrumentation: Wall Current Monitors and new SWICs • g-2 Line • Optics design is conceptual, less mature than other lines • Geometry of “split” between M4 and g-2 lines is still conceptual • Momentum collimation needs to be incorporated into bend region • An additional elevation change of 5 feet is required to get to g-2 Storage Ring level • “Match” into Storage Ring will drive design of downstream part of line…need flexibility • Instrumentation: Ion Chambers and SWICs from BNL J. Morgan

43. External beam lines J. Morgan

44. M4 line optics Delivery Ring through Mu2e collimation section J. Morgan

45. Split between the M4 and g-2 lines • g-2 line splits from M4 line in the middle of the left bends • Bend angle of third dipole is 6° for Mu2e and 3° for g-2 • Both beams pass through large aperture quadrupole after third dipole (“D” quadrupole) • Separation angle between beamlines is 4.5° • BNL quadrupole can be inserted in g-2 line upstream of Mu2e SQC J. Morgan 45

46. New concept for split between M4 and g-2 • g-2 line separates from M4 vertically upstream of Left Bend • Elevation change to Storage Ring height is done in one step • Has implications for tunnel geometry and radiation shielding in Left Bend region • Simplifies optics design because of increased length J. Morgan 46

47. g-2 Line • g-2 line splits from M4 line in the middle of the left bends • Mu2e Left Bend is 40°, g-2 is 28° • Momentum collimation will be integrated into Left Bend • g-2 line is roughly 50 m long (longer with vertical split scenario) • BNL 4Q24 quadrupoles and 4D16 trims will be used in the line • Vertical dogleg for elevation change to experiment • Final focus and matching to Storage Ring will be designed in collaboration with Ring Team J. Morgan

48. g-2 Storage Ring 10 cm beam access port J. Morgan

49. Storage Ring lattice functions and dispersion J. Morgan

50. Magnets made available by reconfiguration of Rings and beam lines J. Morgan