Fermilab, Proton Driver, Muon Beams, RecyclerDavid NeufferFermilab NufACT05

PAC Report

Proton Driver and Muon beams8GeV Linac can produce streams of 1.51014 8GeV protons at 10Hz> 1022 protons/yearOnly 1/15 of these needed for Main Injector

Are there muon beam experiments that could use this intensity ??

Tertiary muon beams:P + X + 10-2 /p 1020 /year or more

PAC Report

Proton Linac (H-)

PAC Report

LFV: m-A e-A can use high intensityDesirable Beam CharacteristicsBut bunched beam is needed

ExperimentI0/Im dT[ns] DT[ms] pm[MeV] Dpm/pm[%] m-A e-Am egm eeem+e- m-e+ 1021101710171016 < 10-10n/an/a< 10-4 < 100n/an/a< 1000 > 1n/an/a> 20 < 80< 30< 30< 30 < 5< 10< 1012 tm 1014< 10-4 100 > 20 30< 10gm-2EDM 10151016 < 10-7< 10-6 < 50< 50 > 103> 103 3100

m-A e-A experimentsNext generation of m-A e-A experiments has been proposedMECO based at BNL PRISM-PRIME based at KEK/JHF

Neither experiment is fully funded

Could either (or both) be hosted at FNAL proton driver ?m-A e-A produces monoenergetic e- (~105MeV)

PAC Report

Past and future LFV limits 100 300 100 300 GeVSUSY predictions of m-A e-A MECO single event sensitivityPRIME single event sensitivity10 -1110 -1310 5From Barbieri,Hall, Hisano

PAC Report

MECO layoutSuperconducting Production Solenoid (5.0 T 2.5 T)Muon Stopping TargetMuon Beam StopCrystal CalorimeterSuperconducting Transport Solenoid (2.5 T 2.1 T)Superconducting Detector Solenoid (2.0 T 1.0 T)CollimatorsTrackerTime structure

PAC Report

PRISM-PRIME (Y. Kuno et al.)High intensity pulsed proton beam (bunch length

Proton Beam requirementsMECO experimentRequires pulses of ~8 GeV protons (

Recycler as accumulator ring ?8GeV Linac produces 1ms pulses at 10 Hz

H- injection into Recycler1ms fills circumference(100 turns)Bunch beam into pattern required for expt.

Harmonic 10 buncher for MECO, slow extraction

Harmonic 100 buncher for PRIME, single bunch extraction

But:Recycler circumference is large100ms may be too short a time for bunching

CircumferenceC=2Rave3320mMomentumP8.89 GeV/cRev. frequency,Periodf0T089.8 kHz11 sSlip factor=1/2- 1/t20.0085Tunesx, y25.4,24.4

PAC Report

Space Charge DifficultySpace Charge tune shift:

Parameters: Ntot=1.51014,N =20 mm-mrad

MECO: 30ns/1s : BF= 0.03 = 4 : too largeReduce N to 1.51013 = 0.4 Reduce N to 0.41013 = 0.1

PRISM/PRIME 10ns bunches, 100/ring BF= 0.1 =1.2: too large (but closer)Larger N, smaller Ntot, Smaller circumference ring would be better

PAC Report

Recycler Bunching (~for PRISM)Harmonic 100 buncher (9MHz)

Bunch for 0.1s (Vrf ramps to 140kV)

Bunch lengths reduced to ~5ns rms(Prism wants < 10ns full width.)

Could then extract bunches one at a time over ~0.1s

Uses 1/2 the possible linac pulses (500 bunches/s for PRISM) (100 at 5Hz)

PAC Report

Recycler Bunching for ~MECOHarmonic 10 buncher (0.9MHz)Barrierbucket rf

Bunch for ~1s (Vrf ramps to ~30kV)

Bunch lengths reduced to ~50ns rms(MECO wants ~30ns full width.)

Could then extract bunches in slow extraction over ~1s

PAC Report

Other potential proton storage schemesAccumulator or Debuncher (C= ~454m) after 2010Large aperture machinesDifficult to inject H- (must bend beam from Linac) (B < 0.05T, > ~600m)

Could take debunched protons from Recycler or Main Injector(in ~450m chunks)Or Old linac + BoosterBunch into pattern needed for experiments Bunching easier than RecyclerBetter match for MECO

PAC Report

Generic High intensity muon beam Detailed m source design does not exist Straw man design worked out for the front end of a n factory supported by MARS simulations (Ray et al.)Target + capture solenoid + drift (forward capture) 1.4 x 1022 protons/year at 8 GeV yields ~3 x 1021 muons/year.Charged particlespectra at end ofdecay channel

PAC Report

ReferencesW. Foster et al., Proton Driver http://tdserver1.fnal.gov/project/8GeVLinac/DesignStudy/W. Molson, The MECO Experiment to Search for -Ne-N with 10-17 Sensitivity, U. Va. Seminar, June 2004MECORSVP Rare Symmetry Violating Processes (MECO-KOPIO) NSF proposal, October 1999.PRISM Working groupAn Experimental Search for the e Conversion Process at an Ultimate Sensitivity of the Order of 1018 with PRISM, The Prime Working Group, Jan. 1, 2003.R. Ray & D. Roberts, Proton Driver physics study

PAC Report

SummaryMuon Beams from the Proton Driver could be very usefulPotential muon beam facilities could be developed:

MECO, PRISM could be hosted More Detailed design needed Proton CollectionRecycler, Accumulator, Debuncher, New Stretcher/Buncher ring ??Beam line(s)Experimental area(s)

PAC Report

Proton Driver Parameters8 GeV LINACEnergyGeV8Particle Type H- Ions, Protons, or ElectronsRep. RateHz10Active Lengthm671Beam CurrentmA25Pulse Lengthmsec1Beam IntensityP / pulse1.5E+14 (can also be H-, P, or e-)P/s1.5E+15Linac Beam PowerMW avg.2MW peak200MAIN INJECTOR WITH 8 GeV LINACMI Beam EnergyGeV120MI Beam PowerMW2.0MI Cycle Timesec1.5 filling time = 1msecMI Protons/cycle1.5E+14 5x designMI Protons/hrP / hr3.6E+17H-minus Injectionturns90 MI Beam CurrentmA2250

PAC Report

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