MANX at MTA

1. MANX at MTA Andreas Jansson Fermilab

2. Foreseen MCTF Experimental R&D • Low energy proton beam to MTA • Foreseen since before, but delayed due to budgetary restrictions. We pushed for it, but not part of MCTF proposal. • Proton intensity upgrade for MTA • Part of MCTF proposal to Director • Muon beam to MTA • Initially to test Helical Cooling Channel, which is also part of MCTF proposal. LEMC Workshop, February 12-16, 2007

3. 6DMANX Helical Cooling Channel [Cummings et al, “A SIX-DIMENSIONAL MUON BEAM COOLING EXPERIMENT”, EPAC06] Default option: stick it in the MICE beamline at RAL… … but, maybe there is another way to do it. LEMC Workshop, February 12-16, 2007

4. First, a disclaimer • Investigating a muon beam experiment does not constitute a decision. • The (HCC) demonstration experiment should be done the way that makes most sense. • We should agree on what we want to demonstrate, and to whom! • Need simulations to make informed decision. • Single particle a la MICE by Muons Inc? • Macro-particle (pencil beam) by Fermilab MCTF • Other bright ideas by anyone? • Initial results by PAC07(?) LEMC Workshop, February 12-16, 2007

5. Why at MTA? D. Broemmelsiek • MTEST very low intensity, energy of muons on the high end,  issues with radiation shielding and compatibility with ongoing ILC tests, to cryo, rate limited by Main Injector availability • MiniBoonewell matched energy, but no space (need new civil construction), no cryo, unclear availability (existing programme), relies on Booster availability • MTA restricted space, muon energy on the low end, high beam availability, facility dedicated to muon R&D, cryo will be available • (Pbar debuncher) not considered (compatibility with proton plan?), but if MECO becomes a reality should reconsider NB. A lot of the discussion is independent of location. LEMC Workshop, February 12-16, 2007

6. Muon beam at MTA? • Can we make a muon beam at MTA with suitable momentum and sufficient intensity? LEMC Workshop, February 12-16, 2007

7. Target, pion capture and decay channel • Carbon target in 6T solenoid. • Quadrupole decay channel (PAC’01 design) N. Mokhov/V. Balbekov LEMC Workshop, February 12-16, 2007

8. Preliminary simulation results • MARS model of target and decay channel (PAC’01 design 42m long). • Working on simulations with shorter channel. • Total yield ~1e-6. • Emittance (rms, unnormalized) of ~500 Pi mm mrad N. Mokhov/V. Balbekov LEMC Workshop, February 12-16, 2007

9. Beam purity (preliminary) • Main contaminant is π+ (50%), π- (~1%) and µ- (~1%). • Protons are absorbed in target. • Need to separate pions from muons • Use a Tevatron electrostatic separator (Wien filter)? • 2.5m long, 2MV/m, gives a differential kick of ~10mrad • Many will be available, soon… • Alternative: thin target to range out pions. • Would affect muon momentum… Pi+ Mu+ LEMC Workshop, February 12-16, 2007

10. Decay Channel in G4Beamline • Implementing the Balbekov/Mokhov target and decay channel in G4BeamLine for comparison • Eventually, should implement entire experimental setup Work in progress LEMC Workshop, February 12-16, 2007

11. Muon yield in G4Beamline vs MARS MARS G4BeamLine v1.06 • 400 MeV (kinetic energy) linac protons on 40cm carbon target in B=6T. • Detector at 0.5m. • So far, not very good agreement… Work in progress LEMC Workshop, February 12-16, 2007

12. Preliminary MTA Muon Beam Parameters • 250 MeV/c average muon momentum, 50MeV/c momentum spread • ~1e6 muons per pulse maximum (peak rate of ~2e11 µ+/second). • Expect to loose two orders of magnitude in reducing transverse emittance (simulations underway). LEMC Workshop, February 12-16, 2007

13. Macro-particle experiment • It is very hard to measure the emittance of a large beam, especially in the presence of non-linear forces. • Use “pencil beam” as macro particle and scan the aperture! • Beam position and angle easy to control and measure. • Can use relatively simple detectors (10000 MIPS vs 1 MIPS). • Insensitive to muon decays (average position is insensitive to 1 particle out of 10000). • Can measure transverse non-linearities and acceptance. LEMC Workshop, February 12-16, 2007

14. 4D Raster Scan “Pencil beam” x’ y’ E x y t x’ y’ E t x y Macro-particle Beam Macro-particle LEMC Workshop, February 12-16, 2007

15. 5D Raster Scan “Pencil beam” x’ y’ E x y t x’ y’ E t x y Macro-particle Macro-particle Macro-particle LEMC Workshop, February 12-16, 2007

16. Expected MANX cooling • Note that when matching is included, MANX is currently heating longitudinally! • Could matching be improved? coupling Matching Matching MANX K. Yonehara LEMC Workshop, February 12-16, 2007

17. G4Beamline simulation • Cooling term is given by the reduction in volume of 5D voxels bounded by raster points. • Heating term is given by the beam emittance at the exit of the HCC (assuming zero initial emittance and far from equilibrium). • Equilibrium emittance can be calculated! y [m] x [m] Distribution of initial zero emittance beam after passing thru HCC+matching (no RF) G4beamline model from K. Yonehara LEMC Workshop, February 12-16, 2007

18. Pencil beam experiment layout Steering dipoles Position and angle measurement HCC Energy distribution measurement Decay channel Electrostatic separator? Transverse collimation Momentum collimation LEMC Workshop, February 12-16, 2007

19. Schematic beam in beam out Position and angle measurement Position inside HCC Position and angle measurement (plus emittance) Spectrometer Steering dipoles Spectrometer LEMC Workshop, February 12-16, 2007

20. First pass at Optics • Dispersion free bend with space for momentum selection and momentum spread measurement. • Matching into HCC with space for steering dipoles and diagnostic. • Need to refine and add eg electrostatic separator. • Need to simulate in eg G4BeamLine. LEMC Workshop, February 12-16, 2007

21. Instrumentation • Fiber tracker developed by PPD for MTEST • Single MIP sensitivity depending on fiber size and electronics • Can probably be used directly in beam lines • May be modified for use in LHe? H. Nguyen et al LEMC Workshop, February 12-16, 2007

22. What About the 6th Dimension? • Near isochronous HCC is important for adding RF. • Lowering the muon rate, one could do a dedicated run to measure time-of-flight distribution as well. • Need to investigate sensitivity and error sources. µ+ Σ stop Σ start LEMC Workshop, February 12-16, 2007

23. Possible extensions to the program • “Simplest” way to add RF to HCC is to interleave HCC sections with RF sections. • Could be added as a second phase. • May also test pressurized RF only with muon beam. HCC with matching sections HCC with matching sections + RF Pressurized RF only LEMC Workshop, February 12-16, 2007

24. To do (not exhaustive list) • Investigate validity of macro-particle assumption (maximum emittance). • Re-optimize HCC for 250MeV/c. • Improved design and simulations of target, decay channel and pion separation. • Refine the experimental setup, including beamline optics, collimator design and detectors. • Simulate, simulate, simulate (to understand eg systematics)… LEMC Workshop, February 12-16, 2007

25. Conclusions • Fermilab director supportive of Muon Collider work • Hopefully, this moral support will eventually translate into a fresh infusion of money. • As part of the MCTF work, we are investigating the possibility of a muon beam at MTA. • Could be used to test the HCC prototype magnet, but also for other things. • We plan to study the performance of such an experiment in more detail, and (hopefully) compare to alternatives. • Could use help, if anyone’s interested… LEMC Workshop, February 12-16, 2007

26. LEMC Workshop, February 12-16, 2007