munu Slides

The High-Emittance Muon Collider David Neuffer June 2009 Low Emittance Muon Collider Workshop Preview 1 Outline  Introduction  Motivation  Scenario Outline and Features      Parameters Proton Driver Front End Accelerator Collider  Upgrade Path(s)  to Low-Emittance Muon Collider 2 Motivation- E. Eichten 3 Other physics  Higgs at high energy  ζ ≈ 0.6pb  0.01 fb-1 is 1030 for 107s  need more to sweep nearby energy  First SuperDimensional DarkMatterEnergy HyperSymmetric Particle??  ζ > pb !! 4 2A 2 TeV 5 HEMC Parameters Proton Linac 8 GeV Parameter Proton Beam Power Bunch frequency Protons per bunch Proton beam energy Number of muon bunches +/-/ bunch Symbol Pp Fp Np Ep nB N Value 2.4 MW 60 Hz 3×1013 8 GeV 12 1011 Accumulator, Buncher Hg target Drift, Bunch, Cool Transverse emittance t,N * * x,y x,y max E+,E_ Nt L0 0.003m 0.05m 10000m 0.013cm 0.55cm 5.4cm 1 TeV (2TeV total) 1000 4×1030 6 Linac RLAs Collision * Collision max Beam size at collision Beam size (arcs) Beam size IR quad Collision Beam Energy Storage turns Collider Ring Luminosity Proton Driver  Proton Driver is variant of Project X    Other variations possible 8 GeV at Fermilab 1.2×1014/cycle Drift, Bunch, Cool Proton Linac 8 GeV Accumulator, Buncher  8 GeV SRF linac , 15 Hz Hg target  Accumulate, Bunch to form 4 bunches  3×1013/bunch  extract at 60Hz • • εN6π =120π mm-mrad, BF = 0.005   2 2  B F  N δν = 0.4 3 rp N tot Linac RLAs Detector Collider Ring 7 Solenoid lens capture  Target is immersed in high field solenoid  Particles are trapped in Larmor orbits  B= 20T -> ~2T  Particles with p < 0.3 BsolRsol/2=0.225GeV/c are trapped  π→μ  Focuses both + and – particles  Drift, Bunch and phase-energy rotation p 8 High-frequency Buncher and φ-E Rotator  Drift (π→μ)  “Adiabatically” bunch beam first (weak 320 to 240 MHz rf)  Φ-E rotate bunches – align bunches to ~equal energies  240to 202 MHz, 15MV/m  Cool beam p 201.25MHz π→μ FE Targ Solenoid et 10 m Drift ~50 m Buncher ~30m Rotator 36m Cooler ~80 m 9 Adiabatic Buncher; φ-E rotation  Set rf phase to be zero for reference energies  Spacing is N rf  rf increases  gradually increase rf gradient  Match to rf= ~1.5m at end:  After bunching rephase rf so that higher energy bunches accelerate, low energy bunches  Finish when bunch energies are aligned in E  Transfer to cooling  Captures both μ+ and μ born from same proton bunch Example: rf : 0.901.5m 10 Bunch train for Collider  Drift, buncher, rotator to get “short” bunch train (nB = 10):  217m ⇒ 125m  57m drift, 31m buncher, 36m rotator  Rf voltages up to 15MV/m (×2/3)  At < 0.03, AL <0.2  Choose best 12 bunches  Obtains ~0.1 μ/p8 in ref. acceptance  3 × 1013 protons • • ~0.008 μ/p8 per bunch ~0.005 μ/p8 in acceptance  1.5× 1011 μ/bunch in acceptance  εt,rms, normalized ≈ 0.003m (accepted μ’s)  εL,rms, normalized≈ 0.034m (accepted μ’s) 11 Simulations (NB=10) s = 1m s = 89m Drift and Bunch Rotate 500 MeV/c s = 125m s = 219m Cool 0 -30m 12 30m HEMC collider bunches  Scenario is unoptimized  ~60% of μ’s in best 12 bunches  ~75% in best 16 13 Acceleration-RLA’s ? 244 MeV 300 m 160 m 1.8 GeV A. Bogacz – Dogbone RLAs 1.2 GeV/pass 7.2 GeV 528 m 32.5GeV 5 GeV/pass Dogbone RLA II example 7 pass Ef E0 = 30 Beam is probably too big for 1300MHz. 800 MHz - OK 32.5 GeV 1000 GeV Linac 140 GeV/pass Dogbone geometry is long. (140 GeV @20MV/m is 7km.) Racetrack is more compact. 14 Collider Ring  12 bunches of μ+ and μ 1011 μ/bunch  β* = 3 to 10 cm  ζ= 0.01 to 0.016cm  βmax = 10000m  ζ=5.5cm (1TeV)  IR quads are large aperture (20cm radius)  δE ~0.12 GeV if ζz = 3cm  δE/E = 10-4  Δν=0.000036  εL =0.012 eV-s  Collider is not beam-beam limited   beam  beam  N  r 4 p  N , rm s 15 Upgrade path  More cooling  εt,N→ 0.0005, β*→1cm  L→1032  Bunch recombination  12→1  L →1033  More cooling  low emittance  εt,N→ 0.00003, β*→0.3cm  L→1034  More Protons  2.4→5MW or more  L→1035 16 Conclusions  An Initial Muon Collider (0.5 to 4 TeV) with low luminosity could be constructed, particularly if motivated by a clear physics goal. Uses trains of μ+ and μ- bunches for acceleration and storage (~ 20m trains)  L= ~4×1030 cm-2s-1  needs little cooling  does need front end (captures both μ+ and μ-)  Could be upgraded to high-luminosity  more cooling  smaller β*  bunch recombination 17 First μ Collider may not be perfect … 18