1. Beam Transport and Storage Rings Design Review November 17, 2010 J. Morgan

2. Mu2e Accelerator Organization 2 Mu2e Accelerator S. Werkema V. Nagaslaev (Deputy) FNAL 2 Mu2e Accelerator S. Werkema V. Nagaslaev (Deputy) FNAL 2.01 Project Management S. Werkema V. Nagaslaev (Deputy) FNAL 2.01 Project Management S. Werkema V. Nagaslaev (Deputy) FNAL 2.02 Recycler I. Kourbanis FNAL 2.02 Recycler I. Kourbanis FNAL 2.03 Transport to Storage Rings J. Morgan B. Drendel (Deputy) FNAL 2.03 Transport to Storage Rings J. Morgan B. Drendel (Deputy) FNAL 2.04 Storage Rings J. Morgan B. Drendel (Deputy) FNAL 2.04 Storage Rings J. Morgan B. Drendel (Deputy) FNAL 2.05 Radiation Safety A. Leveling FNAL 2.05 Radiation Safety A. Leveling FNAL… … 2.06 Resonant Extraction L. Michelotti FNAL 2.06 Resonant Extraction L. Michelotti FNAL 2.07 External Beamline C. Johnstone FNAL 2.07 External Beamline C. Johnstone FNAL 2.08 Extinction E. Prebys FNAL 2.08 Extinction E. Prebys FNAL 2.09 Target Station R. Coleman FNAL 2.09 Target Station R. Coleman FNAL 2.10 Operations Prep. TBD 2.10 Operations Prep. TBD

3. Beam Transport to Storage Rings WBS structure 1.2.3 Beam Transport to Storage Rings 1.2.3.1 Conceptual design 1.2.3.2 Recycler to Accumulator beam line modifications 1.2.3.3 Transport line controls 1.2.3.4 Transport line instrumentation 1.2.3.5 Infrastructure Improvements

4. Storage Rings WBS structure 1.2.4 Storage Rings 1.2.4.1 Post CD-0 conceptual design 1.2.4.2 Post CD-1 conceptual design 1.2.4.3 Accumulator injection 1.2.4.4 Accumulator Ring 1.2.4.5 Beam damper system 1.2.4.6 Beam abort system 1.2.4.7 Storage Rings controls 1.2.4.8 Accumulator extraction 1.2.4.9 Ring to Ring transfer line 1.2.4.10 Debuncher injection 1.2.4.11 Injection and extraction kickers 1.2.4.12 Debuncher Ring 1.2.4.13 Storage Rings instrumentation 1.2.4.14 Infrastructure improvements

5. Assumed off-project improvements Booster is able to deliver 15 Hz beam (4E12 ppp) The MI-8 line connects to the Recycler The Recycler is able to inject protons at 15 Hz Improvements will result in a surplus of Booster beam that can be used by Mu2e – Every Nova cycle (20 batches/1.333 sec.) 12 batches to Nova 6 batches to Mu2e

6. Beam path from Booster to Mu2e experiment 8 GeV kinetic energy beam from Booster takes a long path through mostly existing beam lines to the Mu2e production target. Booster  MI-8 line Partial turn in Recycler Extracted at MI-52 from Recycler to the P1 beam line P1  P2  AP1  AP3  Accumulator Ring Multiple proton batches stacked in Accumulator h=4 RF bunch formation in Accumulator One bunch at a time extracted to the Debuncher Resonantly extracted to the Mu2e external beamline Mu2e external beamline

7. Mu2e beam transfer sequence

8. Selected accelerator parameters Mu2e Beam parameters Booster intensity4.0 E12 Accumulator intensity1.2 E13 Debuncher intensity3.0 E12 Annual to experiment4.0 E20 Kicker ratesInstantaneousAverage Accumulator Injection 15 Hz4.5 Hz Accumulator Extraction 7.5 Hz6.0 Hz Debuncher Injection 7.5 Hz6.0 Hz Accumulator Abort0.2 Hz100/day Debuncher Abort7.5 Hz6.0 Hz

9. Three Booster batches are injected into the Accumulator and decelerated to the central orbit by the 53 MHz RF system 400 nsec FW=150-200ns  ~10 MeV 1.6  sec The beam is then rebunched by the 2.5 MHz system into h=4 buckets Beam is transferred one bunch at a time from the Accumulator to the Debuncher where it is resonantly extracted Beam Intensity: (4.0 E12)  3 = 1.2 E13 Accumulator rebunching

10. Mu2e bunch structure requirement Mu2e experiment requires very narrow beam pulses that are separated by a time interval that is ~ 2  864 nsec (twice the  - lifetime in Al) The narrow pulses are formed by 2.5 MHz RF manipulations in the Accumulator and Debuncher rings. These RF systems require high voltages (~100 kV) for long time intervals (~100 – 400 msec) t 150-200 ns 1.7  s Debuncher revolution period Requirement: ~2  864 ns

11. Beam Transport Overview Conceptual design – No major changes to existing P1, P2, AP-1 and AP-3 lines planned – Mature optics, modified during early part of Run II – Aperture improvements required to improve efficiency (presently 95%) Beam line modifications – Larger aperture magnets needed at several locations – Existing power supplies will be adequate in most cases Controls – CAMAC crates, links and networking already in place Instrumentation – Existing BPM’s and BLM’s can be used, some upgrades to electronics likely needed to distinguish between individual beam transfers – Toroid and multiwire/SEM coverage is adequate, existing resistive wall current monitor can be used Infrastructure improvements – Existing buildings and tunnel enclosures should be OK

12. Existing transport lines

13. List of limiting apertures has been compiled – Expanded from work done in support of Collider Run II Plan for most restrictive apertures – Tevatron injection Lambertson’s (removal) – QF11B, QF12, QF14, QF16 ( modified optics, possible new quadrupole at QF10) – F17 C-Magnets (extraction geometry change) – HV100 dipole string (B-2 magnets) – HV102 dipole string (B-2 magnets) Optics improvements – Existing optics are very mature – Rebusing of quadrupole supplies will provide new degrees of freedom Transport line aperture improvements

14. Alternate beam line – B/A line 8 GeV kinetic energy beam from Booster is injected directly into the Accumulator. MI-8 line  New Beamline New Beamline  A30 Beam circulates in opposite direction, A/D line would need to be relocated Beam extracted to Mu2e from Debuncher at AP50 Main drawback is the cost of the new beam line New Beamlines

15. Accumulator Injection Retain as much of existing scheme as possible – Existing layout of AP-3 into the Accumulator should be OK “Reverse proton” beam follows the same path – Lambertson and “C” magnet are tight apertures – Kicker already located in high dispersion region Injection kicker described later

16. Accumulator Ring Collider equipment removal – General plan has already been created – Cooling stands can be reused RF – LLRF system – H=84 100 kV 53MZ system – H=4 100kV 2.5MHz system – Extraction kicker synchronization – Accumulator to Debuncher H=4 phase jump – System for studies Mechanical and vacuum systems – Vacuum system was designed for ultra-high vacuum – Motion control and most other mechanical systems could be salvaged from removed components RingRF Freq. (MHz) Voltage (kV)Duty factor Accumulator53 MHz (h=84 ) Injection frequency to central orbit (~6.3 kHz), Programmable 100kV 100% at 15Hz Accumulator2.5 MHz (h=4 ) Fixed frequency at the Accumulator central orbit energy 100kV100% at 15Hz

17. Beam damper system Beam stability analysis being provided by colleagues in APC – Damper probably won’t be needed for Debuncher – Damper likely will be needed for Accumulator (subject to further analysis) Consider adding Debuncher damper system to remove beam that isn’t in the main bunch – Gated system phased to excite beam

18. Beam abort system Accumulator system – Low duty cycle, loss of beam permit and beam studies – Kicker would require 100ns rise time, 1.6μs flat-top – Propose kicker that charges in ~30ms to minimize cost – May be more efficient to combine with Debuncher abort When permit drops, transfer down A/D line follow Debuncher beam to abort Would require dual PFN’s for Accumulator extraction kicker – Small dump in A50 pit is base plan Debuncher system – Primary role is to remove beam that wasn’t resonantly extracted – 40% duty cycle, mostly 6.0 Hz rate, 400ns rise and fall time and 1.7μs flat-top – Use existing AP-2 pbar injection configuration with a beam dump in the Transport enclosure – Utilize existing kickers with Booster style septum magnet Would require new power supplies

19. Controls Network – Existing Ethernet infrastructure at AP10, AP30 and AP50 should be sufficient for Storage Rings needs – May need improvement to network infrastructure, controls experts are assisting with cost estimates CAMAC – Existing Camac front ends, repeaters, crates and links are already in place We may need to relocate some CAMAC crates within the service buildings Decommissioned CAMAC cards available for new devices – An inventory of the current CAMAC crates is in progress. – If we have to add any additional crates, we will consolidate existing crates after pbar-specific devices are decommissioned

20. Accumulator extraction D/a line becomes A/D line – Extraction point remains the same “Reverse proton” beam follows the same path – Kickers relocated to low dispersion region Upstream half of 7.3m drift between A1Q5 and A1Q6 has appropriate phase advance for kickers Extraction septa – Two septa presently used in D/A line – Booster style well suited Designed to operate at 15Hz Higher design bend (40 vs. 33 mr) – New power supply required

21. Ring to ring transfer A/D line – Magnet layout and aperture looks good Injection and extraction points will define horizontal aperture – Existing lattice could use some tweaks Matching not as critical because beam will be resonantly extracted – Instrumentation generally adequate Good SEM coverage BPM’s exist, but have not been used operationally There is a toroid at the 806 location

22. Debuncher injection Injection scheme unchanged from current arrangement – Large quad at D6Q6 – Septum between D6Q7 and D6Q6 3.7m drift, existing septum is 2m long – Kickers between D6Q10 and D6Q9 4.1m drift, existing kickers are 3-1m modules New power supply required 2 sextupoles and a trim dipole take up the remaining 1.1m Injection septum – Booster design well suited Designed to operate at 15Hz – New power supply required

23. Injection and extraction kickers Accumulator injection kicker – Must have a very large horizontal aperture – Needs to have 57ns fall time (3 Booster bunches) – Requires a 4mr kick, but limited to 3-4m total length – 30% duty cycle, 15Hz bursts (new power supply) – Existing Accumulator kickers Have the necessary horizontal aperture Have a 75ns fall time (can be shortened with bump magnet) Retrofit modern power feed-throughs Accumulator extraction kicker – Requires relatively fast rise and fall time (100ns) – Relatively high field requirement (Nova design inadequate) – Relocate to low dispersion region, requires a 4mr kick – Tevatron proton injection kicker system meets needs Hope to appropriate Tevatron system after Run II ends Debuncher injection kicker – Requires a 4.6mr kick, but rise and fall requirements less strict – Should be able to reuse existing Debuncher kicker magnets, but new power supply required 400 nsec FW=150-200ns

24. Debuncher ring Collider equipment removal – General plan has already been created RF – LLRF system – H=4 100kV 2.5 MHz system – Bunch narrowing (10kV 5 MHz and 10kV 7.5 MHz) – System for studies Mechanical and vacuum systems – Vacuum system should require minimal modification – Motion control and and most other mechanical systems could be salvaged from removed components

25. Instrumentation Beam Position monitors – Both rings have an adequate BPM coverage – Electronics will need to be upgraded to accommodate fast cycle time Loss monitors – Existing loss monitor systems are not suitable for high intensity, fast cycling machine Will need to replace with a Booster style system Beam intensity – Hope to reuse DCCT’s, but some modification may be needed Debuncher tune – Will probably model system after Booster…involves pinging the beam – Passive system possible utilizing damper Debuncher spill monitor – Use DCCT, modeled after Main Injector

26. Infrastructure Service buildings – Earth and stone material under buildings has developed openings – Removal of stochastic cooling electronics will free up floor space – A50 counting room or AP-30 refrigerator room could be used Tunnel enclosures – Appear to be adequate, although ongoing problems with leaking groundwater Water systems – Pbar 95  LCW and chilled water systems will probably be adequate Power – RF systems will use 600 kW more than what current systems use – Some extraction line power supplies will be housed in AP-30 New transformer will provide additional power for RF and extraction supplies – Additional power needed for other systems approximately offset by removal of unneeded collider equipment

27. Detailed Presentations Storage Rings RF systems (Dave Peterson) Injection and extraction kickers (Dave Vander Meulen) Abort systems (Brian Drendel) Recycler to P1 Beam Transport (Meiqin Xiao)