A Muon Collider Based on a Proton Source Muon Collider – Preparatory Meeting, April 10-11, 2019 Mark Palmer Acknowledgements • MAP Collaboration • IDS-NF Collaboration • MICE Collaboration Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 2 Neutrino Factory (NuMAX) Proton Driver Front End Cool- Acceleration µ Storage Ring n Factory Goal: Broad Applications: 1021 µ+ & µ− per year ing µ+ • Neutrino Factories ν within the accelerator • Colliders from ~100 GeV to 5 GeV acceptance l t r g r 10s of TeV scale . e 0.2–1 1–5 e l r o r e n ν c − n i t g o o l e µ h a r a n t S GeV GeV c o h t a n • Secondary Beams a a i c l n T o e o L h µ-Collider Goals: r n u u C R s C u 281m u C s B t m e D y S a B 126 GeV a s l p u a 6 a c a C c l - c h ~14,000 Higgs/yr C Accelerators: e a i Potential Sources: P A W t D i Single-Pass Linacs Multi-TeV a n M I Lumi > 1034cm-2s-1 • Proton-driver with ionization cooling Share same complex • Positron-driver with low emittance Muon Collider Proton Driver Front End Cooling Acceleration Collider Ring Muon Accelerator Design Status µ+ • Full conceptual designs for NFs ECoM: • Collider effort (US) focused on key r l g t Higgs Factory r r o . e n e l t o r r R&D elements as opposed to a full i e − g r l n t c g g g a o µ to e o h e n r r a a o n n i t S n c n i l t i h a a i a l n o l a i ~10 TeV n T l c e o o conceptual design p b h o C o r L e u u n R h o s e C o o u g s c m B u S C D C t r e C m C y a n o l B S 6 • In 2012, justified by the facts that s l p e e + − u a u a C l D a D a µ µ C c g c - a n B M r 6 c h 6 C i i Accelerators: e a t P F A • Proposed parameters for i W D h n Linacs, RLA or FFAG, RCS I C M some systems appeared Low EMmittance Muon Positron Linac Positron Acceleration Collider Ring extremely challenging Accelerator (LEMMA): Ring • Some concepts could not be 1011 µpairs/sec from + E : e+e− interactions. The small µ CoM “easily” demonstrated production emittance allows lower 10s of TeV • R&D and design progress since 2012 overall charge in the collider rings Positron Linac − µ arguably changes this picture s s t g – hence, lower backgrounds in a u e W n o i g K n r collider detector and a higher R + − o a Muon0 Collider Preparatory Meeting, CERN, April 10-11, 2019 r µ µ t 0 potential CoM energy due to h Accelerators: 1 c neutrino radiation. o Linacs, RLA or FFAG, RCS s I 3 MAP Approach • Conceptual design of individual accelerator sub-systems • Identify performance parameter targets and limitations • Identify R&D requirements • Provide realistic sub-system conceptual designs • Muon Accelerator Staging Study • Explored potential staging options and estimated overall performance • R&D Program • Identify potential showstoppers • Provide targeted effort to identify viable paths forward • Next step planned • Full conceptual design • Sub-system prototypes Support from the European Strategy • Detector & physics analysis process would allow these steps to be pursued Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 4 Muon Accelerator Complex as envisioned by MASS for 1 GeV Proton Fermilab: Linac LBNE Superbeam nSTORM NuMAX 1-3 GeV Proton Higgs Factory To Linac SURF Fermilab no longer a 1 GeV Muon Linac (325MHz) realistic site option 3-7 GeV Proton & To Near Detector(s) for 1-5 GeV Muon Short Baseline Linac(s) Studies Muon Beam R&D Facility A 6 TeV Muon Collider would ft ft have a similar circumference as the Tevatron Ring 5 5 A Multi-TeV Collider Collider Footprint with FNAL site outline Fermilab no longer a realistic site option 3-7 GeV Proton & 1 GeV Proton 1-5 GeV Muon Linac A TeV-Scale Linac(s) Accelerator 1-3 GeV Proton To Linac System SURF NuMAX: ns to SURF R SC Linac L 1 GeV Muon A t Linac (325MHz) o 6 3 G To Near Detector(s) for e V Short Baseline Studies nSTORM 6 6 MAP Neutrino Factory Parameters 7 MAP Collider Parameters Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 8 MAP References • The future prospects of muon colliders and neutrino factories, Boscolo, Delahaye, Palmer, to appear in RAST volume 10, arXiv:1808.01858v2 [physics.acc-ph]. • Muon Accelerators for Particle Physics (MUON), special volume in the Journal of Instrumentation • https://iopscience.iop.org/journal/1748-0221/page/extraproc46 • 20 articles presently posted, with a few more to come… Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 9 Slides to follow: • Will provide an overview of the status of the MAP concepts • Sub-system by sub-system Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 10 Challenges for a m+m- Collider • MW-class proton beam on target a pions a muons • Efficient capture of the produced pions • Capture of both forward and backward produced pions loses polarization • Phase space of the created pions is very large! • Transverse: 20p mm-rad • Longitudinal: 2p m-rad • Emittances must be cooled by factors of ~106-107 to be suitable for multi-TeV collider operation ~1000x in the transverse dimensions ~40x in the longitudinal dimension • The muon lifetime is 2.2 ms lifetime at rest Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 11 Characteristics of the Proton Driver Muon Source • Overarching goals • NF: Provide O(1021) m/yr within the acceptance of a m ring 34 -2 -1 2 • MC: Provide luminosities >10 cm s at TeV-scale (~nb ) Enable precision probe of particles like the Higgs • How do we do this? • Tertiary muon production through protons on target (followed by capture and cooling) 13 12 • Rate > 10 /sec nb = 2×10 Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 12 MAP Feasibility Issues • Proton Driver High Power Target Station • Target Capture Solenoid • Front End Energy Deposition RF in Magnetic Fields • Cooling Magnet Needs (Nb3Sn vs HTS) Performance • Acceleration Acceptance (NF) Rapid cycling magnets or FFA lattices for high E • Collider Ring IR Magnet Strengths/Apertures • Collider MDI SC Magnet Heat Loads (m decay) • Collider Detector Backgrounds (m decay) Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 13 Proton Driver H- beam Recommendations: • No showstoppers Accumulator Ring identified Layout & Injection Orbits • Adapt concept for (Alexahin, Kapin) likely proton source 3.87 kicker for MHz vertical RF extraction V=11 kV Optics: Based on 6-8 GeV Linac Buncher Ring ½ staight + Source Layout & Optics 1 arc cell Accumulator & Buncher (Alexahin) Ring Designs in hand H- stripping requirements same as those established for Fermilab’s Project X Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 14 High Power Target Recommendations: • No showstoppers identified • Challenging engineering required • Optimized capture solenoid • Target module • Remote handling design 1 cm • Leverage neutrino program target MERIT development efforts @CERN MERIT Expt: Compact • LHg Jet in 15T Taper Design • Capability: 8MW @70Hz MAP Staging aims at 1-2 MW a C Target Improved Compact C Target Option Taper Design with 20T • Performance & Cost Solenoid Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 15 Capture Solenoid • A Neutrino Factory and/or Muon Collider Facility requires challenging magnet design in several areas: • Target Capture Solenoid (15-20T with large aperture) Estored ~ 3 GJ O(10MW) resistive coil in high radiation environment Possible application for High Temperature Superconducting magnet technology Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 16 Front End Control of FE Energy Deposition FE Energy Deposition Neuffer 17 CERN SPC Working Group on Future Colliders Buncher and Phase Energy Deposition Rotator Matched to a Validation of FE Full 325 MHz RF Design 325 MHz Initial Cooling performance Validation of gas-filled Channel with gas-filled RF cavity performance cavities Recommendations: • Ready for updates leading to full conceptual design Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 17 17 Cooling Options • Electron/Positron cooling: use synchrotron radiation a For muons DE~1/m3 (too small!) • Proton Cooling: use • A co-moving cold e- beam a For muons this is too slow • Stochastic cooling a For muons this is also too slow • Muon Cooling: use • Use Ionization Cooling a Likely the only viable option • Optical stochastic cooling a Maybe, but far from clear Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 18 Cooling Methods • The unique challenge of muon cooling is its short lifetime • Cooling must take place very quickly • More quickly than any of the cooling methods presently in use a Utilize energy loss in materials with RF re-acceleration Muon Ionization Cooling Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 19 Kaplan Muon Ionization Cooling Advanced techniques a Improved HF Luminosity Simplified Final Cooling requirements MAP Higgs Factory Target PIC assumed in Carlo Rubbia’s Proposal Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 20 Muon Ionization Cooling (Design) Recommendations: • Designs assumed 3 3 Initial 6D Cooling: e6D 60 cm a ~50 mm ; Trans = 67% 20 MV/m RF in magnetic field • Demonstration of 50 MV/m in magnetic field means that a new optimization study is required!! 6D Rectilinear Vacuum Cooling Channel (replaces Guggenheim concept): eT = 0.28mm, eL = 1.57mm @488m Transmission = 55%(40%) without(with) bunch recombination Muon Collider Preparatory Meeting, CERN, April 10-11, 2019 21 Muon Ionization Cooling (Design) Matching • Helical Cooling Channel (Gas-filled RF Cavities): eT = 0.6mm, eL = 0.3mm Late Stage w/ Induction Linac • Final Cooling with 25-30T solenoids (emittance exchange): eT = 55mm, eL = 75mm Muon Collider Preparatory