1. Muon Collider Design Workshop, BNL Dec-09112/01/2009 C.W. Linac Options (talk not much different from talk at High Intensity Proton Accelerator Application Workshop, FNAL October-09 ) Milorad Popovic FNAL

2. Muon Collider Design Workshop, BNL Dec-09212/01/2009 Outline of Talk Past, Ideas, Credits Present Near Future - Cost Dream Just One Man’s Opinion, mostly Fermi centric view

3. Muon Collider Design Workshop, BNL Dec-09312/01/2009 Past, Ideas, Credits Tesla demonstration of pulsed SC Structure, ~1998, SNS Design based on SC Technology, late 1999, Y. Cho Los Alamos ATW, APT, ~1998, D. Chan Foster Proton Driver, 2002 CEBAF CW Upgrade … Muon Collider People contributions Nufact05, CW Proton Linac Linac 2000

4. Muon Collider Design Workshop, BNL Dec-09412/01/2009 Current Thinking (almost)

5. Muon Collider Design Workshop, BNL Dec-09512/01/2009 Front End Small Energy Spread -> DC Injector ~1MeV Poor Capture -> DC 3mA to get out 1mA Isochronous -> short bunch ~54MHz ~325/6MHz Single turn Extraction H-, ~100MeV 1T magnetic Field, no problem with H- Striping Cheap, Compact, Very Efficient ~80% Working example PSI Cyclotron Front End

6. Muon Collider Design Workshop, BNL Dec-09612/01/2009 Conventional Front End Ion Source, H-, DC, < 1mA LEBT, ~30-50 kV, short RFQ, 162MHz, < 2.2MeV, DC, warm MEBT, probably very short “Low” Energy Linac Single Spoke, ~10MeV Double Spoke ~100MeV Triple Spoke ~400MeV Beta=0.81 ~1.2GeV Beta=1, ~2.xGeV FODO, quads (Almost) Copy of ICD-2, Nagaitsev, Solyak, Yakovlev, et al Copy of ICD-1, (Almost) Ostroumov, et al

7. Muon Collider Design Workshop, BNL Dec-09712/01/2009 “High” Energy Linac There is ~40m long warm section at 2.x GeV Kink, ~3 degree between “Low” and “High” Energy Linacs High Energy Linac directed ~toward DUSEL Injection at MI10, 5GeV< Injection energy ≤ 8GeV 0.125mA < H- Current < 1mA -5 Degree <Synchronous Phase < -2 Degree 9 Cell, 9 cavities per Cryo Module FODO, quads outside 16MV/m < Eacc < 18MV/m

8. Muon Collider Design Workshop, BNL Dec-09812/01/2009 1MW@8GeV example, Cost from 2 to 8GeV 125MeV/Cryo module, 12 meters long H- 0.125mA -> 16kW/Cryo Module of RF Cryo Power at 2K 22.5W/cavity ->200W/Cryo module

9. Muon Collider Design Workshop, BNL Dec-09912/01/2009 Transition at 2.x GeV to High Energy Linac There is kink, about 3 degree, and warm transfer line A Double-Bend Achromat!?( Dipole 2meter, 0.25T) RF switching for 2.x GeV Experiments, Additional kick from middle quadrupole Injection of H- to High Energy Linac, (may be line should be isochronous, Buncher?!) Injection of Muons for NuFactory and Muon Collider

10. Muon Collider Design Workshop, BNL Dec-091012/01/2009 High Energy Linac, PARMILA

11. Muon Collider Design Workshop, BNL Dec-091112/01/2009 Injection & Accumulation 125uA current, 1MW@8GeV -> 7.8x10 14, Main Injector can take 1.5x10 14 -> total injection time in Recycler ~200msec To ease Injection, AC Dipole scheme is envisioned, (motivated by misunderstanding Chuck, Muons Inc ) Every 20msec, circulating beam spends 4 msec on foil with H- injected beam

12. Muon Collider Design Workshop, BNL Dec-091212/01/2009 cavity type F [MHz] E acc [MV/m] L eff, mm Ep/E acc B p /E acc mT/(MV/m) R/Q Ω GΩGΩ Q 0,2K  10 9 Q 0,4K  10 9 P 2K [W] P 4K [W] 11-cell, β=0.81 130016.410282.41575022812.7n/a29.92n/a 9-cell, ILC 130018103824.26103627015.0n/a22.46n/a Room (Hope) for Improvement Q o (residual resistance) is main cost driver Poorly understood but under active investigation

13. Slide 13 Example: Dependence on Accelerating Field Gradient (B. Rimmer) cav. dyn. HOM input C static Matthias Liepe, ERL 2009 Cornell University, Ithaca New York

14. Muon Collider Design Workshop, BNL Dec-091412/01/2009 Large scale CW SRF is viable HEP is not alone, ADS, ERLs and FELs have very similar demands Cost “optimization” Crucial - Full multi-variable optimization absolute must, --1.3GHz?? Why Now-Today? Conclusions

15. Muon Collider Design Workshop, BNL Dec-091512/01/2009 Frequency Scaling of Cavity Parameters For superconducting Niobium For superconducting case

16. Muon Collider Design Workshop, BNL Dec-091612/01/2009 H- Source Triumf has few mA DC source, since 1997 Muons Inc. (Dudnikov) has new Penning Source Long ~100ns notches, LEBT “Low” Energy & Chopping Single solenoid, two valves, two trims, two laser ports, 60cm long, sharp notching

17. Muon Collider Design Workshop, BNL Dec-091712/01/2009 Ion Source Pulsed Extractor Doug Moehs 61 mA 0 mA Beam off Beam deflection plates are part of a 50 Ohm transmission line. 75% beam extinction in 750 keV line ~2.2 microseconds between notches

18. Muon Collider Design Workshop, BNL Dec-091812/01/2009 Ion Source Pulsed Extractor Doug Moehs There is also aprox. 400 ns of beam recovery after the notch is turn off. Tomorrow I will look at T2 which is just before the buncher. Over night the notch will be turned off. - D. Moehs

19. Muon Collider Design Workshop, BNL Dec-091912/01/2009 R Tolmin Laser Striping

20. Muon Collider Design Workshop, BNL Dec-092012/01/2009 RFQ Injection Energy can be low, ~20keV (peak current is low) Final Energy < 2.2MeV (bellow neutron production) RF 162MHz Holes for Laser Beam Warm, Q< few 1000, to have fast Amplitude/Phase Control Fast Phase change for π/4 as way of chopping NO MEBT (Almost) Assumption is that all chopping can be done at extraction from source and using Laser(s) H- neutralization and RFQ phase shifting.

21. Jan-0821 Ankenbrandt and Popovic, Fermilab 21  ->eg-2  Test Facility Booster-era Beam Transfer Scheme Rare Kaon Decays New 200-kW target station that can be upgraded to >2 MW

22. Jan-0822 Ankenbrandt and Popovic, Fermilab 22 Beam Path to 200kW target station in Project X Era

23. 23 Sitting of mu2e, g-2, Kaons,  test area, 4GeV Factory mu2e g-2  test area factory Rare Ks Nufact09-IIT 2307/24/2009

24. Jan-0824 Ankenbrandt and Popovic, Fermilab 24 Path of Beams to 4 GeV Factory in Project XLR8 Era

25. Neutrino Factory as 1 st Step Toward Muon Collider 1GeV H- Linac  <1 Structure 7GeV H- Linac  =1 Structure Proton Accumulation, Bunching Ring, 10 bunches 5x14GeV  Linac  =1, 50Hz 1 GeV,200MHz  Linac 4 GeV,400MHz DogBone  Linac 2-4MW-Target  Capture/Bunching/Cooling Proton Driver 2-4MW, 5Hz

26. 8GeV H- Beam H-Striping&Proton Accumulation Bunching Targeting  CuptureBunchingCoolingAcceleration DUSEL 4 or 40GeV -Fact

27. Bunch Merging Linac 80GeV Linac 80GeV Linac Collider Ring Muon Collider Stage

29. WG-2, High Intensity Proton Accelerator Application Workshop, FNAL October-09 2912/01/2009

30. Muon Collider Design Workshop, BNL Dec-093012/01/2009 The Carbon foil is 200ugr/cm^2, beam spot is 0.3 cm radius, 1.5x10^14, 5Hz, Linac Current CW125uAmp, 430turns per injection

31. Muon Collider Design Workshop, BNL Dec-093112/01/2009