muon collider r&d steve geer accelerator physics center fermi national accelerator laboratory...

MUON COLLIDER R&D

Steve GeerAccelerator Physics Center

Fermi National Accelerator Laboratory

Accelerator Seminar

SLAC., March 24, 2011

m+ m-

n

Muon Accelerator Program - MAP

PHYSICS LANDSCAPE

STEVE GEER Accelerator Seminar SLAC 24 March, 2011 2

DECISION TREE


Pierre Oddone

MUON COLLIDER MOTIVATION


CO

ST

PH

YS

ICS

· 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 wouldfit on the Fermilab Site

ENERGY SPREAD


Beamstrahlung in any e+e- collider

E/E 2

l+l- → Z’ → m+m-


ENERGY SCANm+m- with ISR+BStr (Eichten)

e+e- with ISR

e+e- with ISR+BStr

Z’ Lineshape

EV

EN

T

RA

TE

1600

1200

800

400

0

√s (GeV)2900 2950 3000 3050 3100

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.


MUON COLLIDER SCHEMATIC


Proton source: Example: upgraded PROJECT X (4 MW, 2±1 ns long bunches)

1021 muons per year that fit within the acceptance of an accelerator: eN=6000 mm e//N=25 mm

√s = 3 TeV Circumference = 4.5kmL = 3×1034 cm-2s-1 m/bunch = 2x1012

s(p)/p = 0.1%eN = 25 mm, e//N=70 mmb* = 5mmRep Rate = 12Hz

Muon Collider cf. Neutrino Factory


NEUTRINOFACTORY

MUONCOLLIDER

In present MC baseline design, Front End is same as for NF

A DECADE OF PROGRESSNF 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


A DECADE OF PROGRESSFront-End Design

Parameter Drift Buncher Rotator Cooler

Length (m) 56.4 31.5 36 75

Focusing (T) 2 2 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

p± → mn

Front-end uses NCRF in a lattice of solenoids


A DECADE OF PROGRESSFront-End Simulations

With a 4MW proton source, this will enable O(1021) muons/year to be produced, bunched, cooled & fit within the acceptance of an accelerator.

Neuffer


• 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 !

Hg jet in a 15 T solenoidMeasured disruption length

= 28 cm

1 cm

A DECADE OF PROGRESSSuccessful completion of MERIT


A DECADE OF PROGRESSIonization 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 Liq. H2 Liq. H2

RF RF

RF

liquid H

2solenoid

High Field (HTS) Solenoids


• 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

Palmer• Some components

beyond state-of-art:o Very high field HTS

solenoids & High gradient RF cavities operating in few Tesla fields

• Challenging are the solenoids in the last stages of cooling:

o Original design needed 50 T solenoids. Recent improvements suggest 30 T sufficient.

A DECADE OF PROGRESSIonization cooling concepts & simulations

HTS

30T


PROGRESS THIS YEARIonization cooling concepts & simulations

A DECADE OF PROGRESSMuCool 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.

Liq. H2 absorber (KEK) 201 MHz cavities(LBNL et al.)

42 cm Æ Be RFwindow (LBNL)

High Pressure RF Cavity (FNAL & Muons Inc.)

FIRST BEAM IN MTA 28 FEBRUARY 2011 !


Muon Beam

Spectro-

meter

Cooling

section

Spectro-

meter

• Multi-stage experiment at RAL to be completed ~2014

MICE – upstream beamline

- Tests short cooling section, in muon beam, measuring the muons before & after the cooling section. one at a time.

- Learn about cost, complexity, & engineeringissues associated with cooling channels.- Vary RF, solenoid & absorber param-

eters & demonstrate ability to simulate response of muons

A DECADE OF PROGRESSMuon Ionization Cooling Experiment (MICE)


A DECADE OF PROGRESSMuon Ionization Cooling Experiment (MICE)

Spectrometer Solenoid

MICE HALL

Liq. H2 Absorber

Tracker in cosmic ray test stand RF Cavity

A DECADE OF PROGRESSCollider 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.

MARS energy deposition map for a 1.5 TeV collider dipole

√s=1.5 TeV

A DECADE OF PROGRESSDetector 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 .

A DECADE OF PROGRESSNew 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 backgroundparticle densities in detector

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.”

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.

MAP ORGANIZATION


“”Level 0”

“Level 1”

ORGANIZATION: L1 & L2


• L2 assignments - FNAL; 4½ people - Other Labs: 3 people - Universities: 3½ people - SBIR Companies: 1 person

“Level 1”

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)

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

TECHNICAL CHALLENGESTarget 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

20T Target Solenoid – Conductor radiation tests – Radiation damage

simulations & verification– Target station radiation

simulations (MARS)– Thermal management

studies?– Model magnet radiation

tests

TECHNICAL CHALLENGESNCRF in Magnetic Fields


• Significant degradation in maximum stable operating gradient for NCRF copper cavities in few Tesla coaxial field

• Ongoing R&D program to maximize gradient in B field:(i) high pressure gas filled cavities, (ii) Be cavities, (iii) ALD, (iv) magnetic insulation

Mucool Test Area

805 MHz

TECHNICAL CHALLENGESHigh Field Solenoids


10

100

1000

10000

0 5 10 15 20 25 30 35 40 45 Applied Field (T)

J E (

A/m

m²)

YBCO Insert Tape (B|| Tape Plane) YBCO Insert Tape (B Tape Plane) MgB2 19Fil 24% Fill (HyperTech) 2212 OI-ST 28% Ceramic Filaments NbTi LHC Production 38%SC (4.2 K) Nb3Sn RRP Internal Sn (OI-ST) Nb3Sn High Sn Bronze Cu:Non-Cu 0.3

YBCO B|| Tape Plane

YYBBCCOO BB TTaappee PPllaannee

2212

RRRRPP NNbb33SSnn

BBrroonnzzee NNbb33SSnn MgB2

NNbb--TTii SSuuppeerrPPoowweerr ttaappee uusseedd iinn rreeccoorrdd bbrreeaakkiinngg NNHHMMFFLL iinnsseerrtt ccooiill 22000077

1188++11 MMggBB22//NNbb//CCuu//MMoonneell CCoouurrtteessyy MM.. TToommssiicc,, 22000077

427 filament strand with Ag alloy outer sheath tested at NHMFL

Maximal JE for entire LHC Nb Ti strand production (CERN-T. Boutboul '07)

CCoommpplliieedd ffrroomm AASSCC''0022 aanndd IICCMMCC''0033 ppaappeerrss ((JJ.. PPaarrrreellll OOII--SSTT))

44554433 ffiillaammeenntt HHiigghh SSnn BBrroonnzzee--1166wwtt..%%SSnn--

00..33wwtt%%TTii ((MMiiyyaazzaakkii--MMTT1188--IIEEEEEE’’0044))

FNAL TD test cable. Test degradation of Jc

in cabling process

· 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

PB

L (S

BIR

) 3

5T

de

sig

n

NH

MF

L Y

BC

O T

est

C

oil

(27

T –

DB

= 7

T)

IMPACT OF MUON COLLIDERDESIGN FEASIBILITY STUDY


Based on NASA Technology Readiness Levels

NOWPROPOSED MC-DFS

1

2

3

4

5

6

7

Targ

et &

Dum

p

Bunch

/ Pha

se

Initia

l Coo

ling

6D C

oolin

g

Final

Coo

ling

Pre-A

ccel

erat

ion

Accel

erat

ion

Ring

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

PAST-PRESENT-FUTURE


NFMCCNFMCC

+MCTF

InterimMAP

MAP

FY07 –FY09

FY10 ≥FY11

~4 M$ ~9 M$ ~10 M$ ~15 M$ (requested)

First~10 years

MAP

NOW


http://conferences.fnal.gov/muon11/

INFORMING THE COMMUNITY

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

A VISION


2 MW at ~3 GeVflexible time structureand pulse intensities

2 MW (60-120 GeV)1300 km

START WITHPROJECT X

NeutrinosMuonsKaonsNuclei

“simultaneously”

A VISION


ADD NEUTRINOFACTORY

Enhanced NeutrinosEnhanced MuonsMuon Collider test bedKaonsNuclei

“simultaneously”

4MW protons5 GeV muons1300 km

A VISION


ADD MUON

COLLIDER m+m-

4 TeV Collider

muon collider r&d steve geer accelerator physics center fermi national accelerator laboratory...

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