The High-Emittance Muon Collider

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1 The High-Emittance Muon The High-Emittance Muon Collider Collider David Neuffer June 2009 Low Emittance Muon Collider Workshop Preview

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The High-Emittance Muon Collider. David Neuffer June 2009 Low Emittance Muon Collider Workshop Preview. Outline. Introduction Motivation Scenario Outline and Features Parameters Proton Driver Front End Accelerator Collider Upgrade Path(s) to Low-Emittance Muon Collider. - PowerPoint PPT Presentation

Transcript of The High-Emittance Muon Collider

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The High-Emittance Muon The High-Emittance Muon ColliderCollider

David Neuffer

June 2009Low Emittance Muon Collider Workshop Preview

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OutlineOutline

Introduction Motivation

Scenario Outline and Features Parameters Proton Driver Front End Accelerator Collider

Upgrade Path(s) to Low-Emittance Muon Collider

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Motivation- E. EichtenMotivation- E. Eichten

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Other physics Other physics

Higgs at high energy σ ≈ 0.6pb

0.01 fb-1 is 1030 for 107s need more to sweep

nearby energy First

SuperDimensional DarkMatterEnergy HyperSymmetric Particle?? σ > pb !!

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2A

2 TeV

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HEMC Parameters HEMC Parameters

Parameter Symbol Value

Proton Beam Power Pp 2.4 MW

Bunch frequency Fp 60 Hz

Protons per bunch Np 3×1013

Proton beam energy Ep 8 GeV

Number of muon bunches nB 12

+/-/ bunch N 1011

Transverse emittance t,N 0.003m

Collision * * 0.05m

Collision max * 10000m

Beam size at collision x,y 0.013cm

Beam size (arcs) x,y 0.55cm

Beam size IR quad max 5.4cm

Collision Beam Energy E+,E_ 1 TeV (2TeV total)

Storage turns Nt 1000

Luminosity L0 4×1030

Proton Linac 8 GeV

Accumulator,Buncher

Hg target

Linac

RLAs

Collider Ring

Drift, Bunch, Cool

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Proton DriverProton Driver

Proton Driver is variant of Project X Other variations possible 8 GeV at Fermilab

8 GeV SRF linac , 15 Hz 1.2×1014/cycle

Accumulate, Bunch to form 4 bunches 3×1013/bunch

• εN6π =120π mm-mrad, BF = 0.005

• δν = 0.4 extract at 60Hz

Proton Linac 8 GeV

Accumulator,Buncher

Drift, Bunch, Cool

Hg target

Linac

RLAs

Collider Ring

Detector

p tot

2F N

3r N

2 B

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Solenoid lens captureSolenoid 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

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High-frequency Buncher and High-frequency Buncher and φφ-E -E RotatorRotator

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 201.25MHz

10 m ~50 m

FE

Targ et

Solenoid Drift Buncher Rotator Cooler

~30m 36m ~80 m

p

π→μ

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Adiabatic Buncher; Adiabatic Buncher; φφ-E rotation-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 : 0.901.5m

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Bunch train for ColliderBunch 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)

Obtains ~0.1 μ/p8 in ref. acceptance At < 0.03, AL <0.2 Choose best 12 bunches

• ~0.008 μ/p8 per bunch

• ~0.005 μ/p8 in acceptance

3 × 1013 protons 1.5× 1011

μ/bunch in acceptance

εt,rms, normalized ≈ 0.003m (accepted μ’s)

εL,rms, normalized≈ 0.034m (accepted μ’s)

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Simulations (NSimulations (NBB=10)=10)

-30m 30m

500 MeV/c

0

Drift andBunch

s = 89ms = 1m

Rotate

s = 125m s = 219m

Cool

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HEMC collider bunchesHEMC collider bunches

Scenario is unoptimized ~60% of μ’s in best 12

bunches ~75% in best 16

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Acceleration-RLA’s ? Acceleration-RLA’s ?

1.2 GeV/pass7.2 GeV

1.8 GeV244 MeV

300 m

160 m

5 GeV/pass

528 m32.5GeV

7 pass Ef

E0

= 30Dogbone RLA II example

Linac

140 GeV/pass

32.5 GeV

1000 GeV

Dogbone geometry is long. (140 GeV @20MV/m is 7km.)Racetrack is more compact.

A. Bogacz – Dogbone RLAs

Beam is probably too big for 1300MHz.800 MHz - OK

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Collider RingCollider Ring

12 bunches of μ+ and μ-

1011 μ/bunch

β* = 3 to 10 cm σ= 0.01 to 0.016cm

βmax = 10000m σ=5.5cm (1TeV) IR quads are large aperture (20cm

radius)

εL =0.012 eV-s δE ~0.12 GeV if σz = 3cm δE/E = 10-4

Collider is not beam-beam limited Δν=0.000036

,4 beam beamN rms

N r

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Upgrade pathUpgrade 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

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ConclusionsConclusions

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

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First First μμ Collider may not be perfect Collider may not be perfect ……