Muon Accelerator Program - MAP MUON COLLIDER R&D Steve Geer Accelerator Physics Center Fermi National Accelerator Laboratory Accelerator Seminar SLAC., March 24, 2011 m+ m- n Muon Accelerator Program - MAP

Accelerator Seminar SLAC 24 March, 2011 PHYSICS LANDSCAPE STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 DECISION TREE Pierre Oddone STEVE GEER Accelerator Seminar SLAC 24 March, 2011

MUON COLLIDER MOTIVATION If we can build a muon collider, it is an attractive multi-TeV lepton collider option because muons don’t radiate as readily as electrons (mm / me ~ 207): - COMPACT Fits on laboratory site - MULTI-PASS ACCELERATION Cost Effective operation & construction - MULTIPASS COLLISIONS IN A RING (~1000 turns) Relaxed emittance requirements & hence relaxed tolerances - NARROW ENERGY SPREAD Precision scans, kinematic constraints - TWO DETECTORS (2 IPs) - DTbunch ~ 10 ms … (e.g. 4 TeV collider) Lots of time for readout Backgrounds don’t pile up - (mm/me)2 = ~40000 Enhanced s-channel rates for Higgs-like particles A 4 TeV Muon Collider would fit on the Fermilab Site COST PHYSICS STEVE GEER Accelerator Seminar SLAC 24 March, 2011

ENERGY SPREAD Beamstrahlung in any e+e- collider E/E  2 STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 l+l- → Z’ → m+m- ENERGY SCAN m+m- with ISR+BStr (Eichten) e+e- with ISR e+e- with ISR+BStr Z’ Line shape EVENT RATE 1600 1200 800 400 √s (GeV) 2900 2950 3000 3050 3100 STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 CHALLENGES Muons are produced as tertiary particles. To make enough of them we must start with a MW scale proton source & target facility. Muons decay  everything must be done fast and we must deal with the decay electrons (& neutrinos for CM energies above ~3 TeV). Muons are born within a large 6D phase-space. For a MC we must cool them by O(106) before they decay  New cooling technique (ionization cooling) must be demonstrated, and it requires components with demanding performance (NCRF in magnetic channel, high field solenoids.) After cooling, beams still have relatively large emittance. STEVE GEER Accelerator Seminar SLAC 24 March, 2011

MUON COLLIDER SCHEMATIC √s = 3 TeV Circumference = 4.5km L = 3×1034 cm-2s-1 m/bunch = 2x1012 s(p)/p = 0.1% eN = 25 mm, e//N=70 mm b* = 5mm Rep Rate = 12Hz 1021 muons per year that fit within the acceptance of an accelerator: eN=6000 mm e//N=25 mm Proton source: Example: upgraded PROJECT X (4 MW, 2±1 ns long bunches) STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Muon Collider cf. Neutrino Factory In present MC baseline design, Front End is same as for NF STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS NF Feasibility Studies Successful completion of NF feasibility studies 1, 2, 2a, & International Scoping Study; launching of the ongoing International Design Study for a NF (IDS-NF) Solid basis for planning the MC Design Feasibility Study (DFS) Real progress on understanding how to make enough muons, capture them into bunches, reduce their energy spread, and begin to reduce their transverse phase space (ionization cooling). IDS-NF community plans to produce a Reference Design Report (RDR) in ~ 2 years. Interim Design Report (IDR) has just been finalized, and is to be reviewed by an ECFA sub-panel May 5-6, 2011 STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Front-End Design p± → mn Front-end uses NCRF in a lattice of solenoids Parameter Drift Buncher Rotator Cooler Length (m) 56.4 31.5 36 75 Focusing (T) 2 2.5 (ASOL) RF f (MHz) 360 ® 240 240 ® 202 201.25 RF G (MV/m) 0 ® 15 15 16 Total RF (V) 126 360 800 STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Front-End Simulations Neuffer With a 4MW proton source, this will enable O(1021) muons/year to be produced, bunched, cooled & fit within the acceptance of an accelerator. STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Successful completion of MERIT Proof-of-principle demonstration of a liquid Hg jet target in high-field solenoid ran at CERN PS in Fall 2007. Successfully demonstrated a 20m/s liquid Hg jet injected into a 15 T solenoid, & hit with a suitably intense beam (115 KJ / pulse !). Results suggest this technology OK for beam powers up to 8 MW with rep. rate of 70Hz ! 1 cm Hg jet in a 15 T solenoid Measured disruption length = 28 cm STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Ionization Cooling TRANSVERSE COOLING: Muons lose energy by in material (dE/dx). Re-accelerate in longitudinal direction  reduce transverse emittance. Coulomb scattering heats beam  low Z absorber. Hydrogen is best, but LiH also OK for the early part of the cooling channel. 6D COOLING: Mix transverse & longitudinal degrees of freedom during cooling. Can be done in helical solenoids. FINAL COOLING: To get the smallest achievable transverse emittance, over-cool the longitudinal emittance, and then work only on the transverse emittance letting the longitudinal phase space grow. εt,,N (m) Liq. H2 RF High Field (HTS) Solenoids STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Ionization cooling concepts & simulations Development of a cooling channel design to reduce the 6D phase space by a factor of O(106) → luminosity O(1034) cm-2 s-1 Some components beyond state-of-art: Very high field HTS solenoids & High gradient RF cavities operating in few Tesla fields Challenging are the solenoids in the last stages of cooling: Original design needed 50 T solenoids. Recent improvements suggest 30 T sufficient. Palmer 30T HTS STEVE GEER Accelerator Seminar SLAC 24 March, 2011

PROGRESS THIS YEAR Ionization cooling concepts & simulations STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS MuCool Test Area MTA built at end of FNAL Linac for ionization cooling component testing 5 T magnet, RF power at 805 MHz & 201 MHz, clean room, LH2 handling capability, 400 MeV beam from linac. FIRST BEAM IN MTA 28 FEBRUARY 2011 ! 42 cm Æ Be RF window (LBNL) High Pressure RF Cavity (FNAL & Muons Inc.) 201 MHz cavities (LBNL et al.) Liq. H2 absorber (KEK) STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Muon Ionization Cooling Experiment (MICE) Multi-stage experiment at RAL to be completed ~2014 - Tests short cooling section, in muon beam, measuring the muons before & after the cooling section. one at a time. - Learn about cost, complexity, & engineering issues associated with cooling channels. Vary RF, solenoid & absorber param- eters & demonstrate ability to simulate response of muons Spectro- meter Cooling section Spectro- meter Muon Beam MICE – upstream beamline STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Muon Ionization Cooling Experiment (MICE) Spectrometer Solenoid Tracker in cosmic ray test stand RF Cavity Liq. H2 Absorber MICE HALL STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Collider Ring Emittances are large, but the muons circulate for only ~1000 turns before they decay. - First lattice designs exist. Need high field dipoles & quadrupoles that operate in large muon decay backgrounds Have studied open mid-plane magnet design (radiation & heat loads, field non-uniformity & affect on lattice performance) → looks OK. - More engineering studies needed. √s=1.5 TeV MARS energy deposition map for a 1.5 TeV collider dipole STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS Detector Backgrounds Muon Collider detector backgrounds studied ~10 yrs ago (1996-1997). Most detailed work done for a s=4 TeV Collider. The electron decay angles from m→enn are O(10) mradians . Electrons typically stay inside beampipe for ~6m. Hence decay electrons born within a few meters of the IP are benign. Shielding strategy: sweep the electrons born further than ~6m from the IP into ~6m of shielding. MARS & GEANT studies gave consistent results. After optimization of shielding, for  s=4 TeV, particle densities in inner detectors similar to LHC @ 1034 cm-2 s-1 . STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A DECADE OF PROGRESS New Detector Studies New detector studies under way – initially for √s=1.5 TeV. Initial shielding configuration exists Reliable MARS simulations exist (NEW: can now simulate decays from 1012 muons with ~ weight 1 “events” !) Initial detector studies beginning Much needs to be understood & optimized ILC – like detector with Muon Collider shielding cones MARS map of background particle densities in detector STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 THE BIRTH OF MAP Oct 1, 2009 letter from Denis Kovar to FNAL Director: “Our office believes that it is timely to mount a concerted national R&D program that addresses the technical challenges and feasibility issues relevant to the capabilities needed for future Neutrino Factory and multi-TeV Muon Collider facilities. ...” Letter requested a new organization for a national Muon Collider & Neutrino Factory R&D program, hosted at FNAL. Muon Accelerator Program organization is now in place & functioning: >200 participants from 15 institutions: ANL, BNL, FNAL, JLab, LBNL, ORNL, SLAC, Cornell, IIT, Princeton, UCB, UCLA, UCR, U-Miss, U. Chicago http://map.fnal.gov/ MAP R&D proposal reviewed August 2010 … committee concluded that the “proposed work was very important to the field of high energy physics.” STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 MAP MISSION STATEMENT The mission of the Muon Accelerator Program (MAP) is to develop and demonstrate the concepts and critical technologies required to produce, capture, condition, accelerate, and store intense beams of muons for Muon Colliders and Neutrino Factories. The goal of MAP is to deliver results that will permit the high-energy physics community to make an informed choice of the optimal path to a high-energy lepton collider and/or a next-generation neutrino beam facility. Coordination with the parallel Muon Collider Physics and Detector Study and with the International Design Study of a Neutrino Factory will ensure MAP responsiveness to physics requirements. STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 MAP ORGANIZATION “”Level 0” “Level 1” STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 ORGANIZATION: L1 & L2 “Level 1” L2 assignments - FNAL; 4½ people - Other Labs: 3 people - Universities: 3½ people - SBIR Companies: 1 person STEVE GEER Accelerator Seminar SLAC 24 March, 2011

PROPOSED MAP PLAN / DELIVERABLES Deliver on our commitments to making MICE and the IDS-NF studies a success. Deliver a Design Study to enable the community to judge the feasibility of a multi-TeV Muon Collider (~FY16): (i) an end-to-end simulation of a MC complex based on technologies in-hand or that can be developed with a specified R&D program. (ii) hardware R&D and experimental tests to guide & validate the design work. (iii) Rough cost range. (iv) R&D plan for longer term activities (e.g. 6D cooling expt) STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 TECHNICAL CHALLENGES There has been much progress over the last decade, but there remains many technically challenging issues that must be addressed before a Muon Collider can be built: High field solenoids operating close to the target (4MW beam) RF operation in magnetic fields The last few stages of the cooling channel Cost effective acceleration Background mitigation & understanding detector performance STEVE GEER Accelerator Seminar SLAC 24 March, 2011

TECHNICAL CHALLENGES Target Solenoids For a MW-class proton beams How radiation hard can we make the solenoids? What thermal loads can we manage? Need R&D to establish the limitations & build confidence in our target station designs Conductor radiation tests Radiation damage simulations & verification Target station radiation simulations (MARS) Thermal management studies? Model magnet radiation tests 20T Target Solenoid STEVE GEER Accelerator Seminar SLAC 24 March, 2011

TECHNICAL CHALLENGES NCRF in Magnetic Fields Significant degradation in maximum stable operating gradient for NCRF copper cavities in few Tesla coaxial field 805 MHz Mucool Test Area Ongoing R&D program to maximize gradient in B field: (i) high pressure gas filled cavities, (ii) Be cavities, (iii) ALD, (iv) magnetic insulation STEVE GEER Accelerator Seminar SLAC 24 March, 2011

TECHNICAL CHALLENGES High Field Solenoids At the end of cooling channel want very high field (~30T) solenoids On going national R&D to develop very high field HTS solenoids. Great promise but many challenges: Conductor performance Quench protection stresses PBL (SBIR) 35T design NHMFL YBCO Test Coil (27T – DB = 7T) FNAL TD test cable. Test degradation of Jc in cabling process STEVE GEER Accelerator Seminar SLAC 24 March, 2011

IMPACT OF MUON COLLIDER DESIGN FEASIBILITY STUDY NOW 1 2 3 4 5 6 7 PROPOSED MC-DFS MUON COLLIDER PROPOSAL 7. System Prototype 6. Sub-System Beam Tests 5. Semi-realistic sub-systems 4. Early sub-system Bench Tests 3. Component R&D 2. Technical Concept 1. Basic Idea Ring 6D Cooling Target & Dump Bunch / Phase Initial Cooling Final Cooling Acceleration Pre-Acceleration Based on NASA Technology Readiness Levels STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 PAST-PRESENT-FUTURE First ~10 years FY07 – FY09 FY10 NOW ≥FY11 MAP Interim MAP NFMCC + MCTF MAP NFMCC ~4 M$ ~9 M$ ~10 M$ ~15 M$ (requested) STEVE GEER Accelerator Seminar SLAC 24 March, 2011

INFORMING THE COMMUNITY http://conferences.fnal.gov/muon11/ STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 FINAL REMARKS MAP is up and running: MAP Management plan signed by DOE-OHEP MAP Director search is under way (https://fermi.hodesiq.com/job_detail.asp?JobID=2339416) There is a real chance to show, within ~6 years, that a multi-TeV Muon Collider is feasible with an estimated cost range, and to specify the remaining R&D needed. The proposed plan requires ~15M$/yr (FY10 dollars) Many challenges, but we believe we can succeed STEVE GEER Accelerator Seminar SLAC 24 March, 2011

A VISION START WITH PROJECT X 2 MW (60-120 GeV) 1300 km Neutrinos Muons Kaons Nuclei “simultaneously” 2 MW (60-120 GeV) 1300 km 2 MW at ~3 GeV flexible time structure and pulse intensities STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 A VISION ADD NEUTRINO FACTORY Enhanced Neutrinos Enhanced Muons Muon Collider test bed Kaons Nuclei “simultaneously” 4MW protons 5 GeV muons 1300 km STEVE GEER Accelerator Seminar SLAC 24 March, 2011

Accelerator Seminar SLAC 24 March, 2011 A VISION ADD MUON COLLIDER m+ m- 4 TeV Collider STEVE GEER Accelerator Seminar SLAC 24 March, 2011