Machine Requirements from Muon WG

Akira SATOOsaka University

NuFact05

Contents

Muon beam requirements

Machine reqirements

J-PARC case

FNAL case

Summary

Experiment Charge Intensity Pulse width Pulse interval Energy Mom. spread Polarization Note

(µ/107sec)(µs) (µs) (MeV) (%) n/a

µ!e" + 1015 DC #1 1 #10 Depol e comtami. # 10-2, beam size cm

µN!eN' (MECO type) $ 1021 10-100 1-1000 #20 #10 n/a

µN!eN' (PRISM type) $ 1020 10-100 1-1000 #20 3 n/a % comtami. # 10-15, beam size cm

g-2 ± 1015#15 &1000 3100 10-2 Pol

edm ± 1018#50 &1000 200-400 10-3 n/a

µ lifetime + 1014 !100 30-100 4 1-10 % beam

µ lifetime (%) + 1014 !100 30-100 4 1-10 100%

Michel parmammeter + 1016#0.5 &0.02 30-40 1-3 !100%

Pol param. + 1016#0.5 &0.02 30-40 1-3 Pol

µ-atoms $ 1016#100 100-1000 1-4 1-5 n/a e comtami. # 10-2, beam size cm

Life science $ 1015 1 100-1000 1-4 1-5 n/a beam size mm

µCF $ 1019 1 &1000 &100

µSR ± 109/s DC - 4 1-5 !100%

µSR ± 1010-20/s 0.001 100 4 1-5 !100%

Muon Beam Requirementsfor Future Muon Program

MLF@ J-PARC

MEG@PSI

Muon Trio at NuFact

New generation of Muon Trio

Use the front end of NuFact

Use a high intense proton driver and construct muon facility.

current limit at NuFactµN→eN’ BR(Ti)<10-13 BR(Ti)<10-18

g-2 0.54 ppm 0.05 ppmedm 10-19 e.cm 10-24 e.cm

Machine RequirementsTo carry out these experiments, we need

high power proton beam ~1MW- a few MW

pulsed proton beam width ~10ns

single bunch fast extraction

to change beam structure to muon experiment required one, accumulator ring would be necessary

ex. J-PARC : + 3GeV-RCS + 50GeV-MR

FNAL : 8GeV-Linac + recycler

Pulsed Proton Beam Facility at J-PARC

NuFact03@Colombia University2003/6/6

Pulsed Proton Beam Facility at J-PARCPulsed Proton Beam Facility at J-PARC

50GeV-PS at J-PARC

! High intensity 0.75 MW

" 1014proton/sec

" Upgradable to 4x1014proton/sec

! A narrow bunched :

for phase rotation

New Fast extraction line is necessary

LOI was submitted to J-PARC Request for A Pulsed Proton Beam Facility at J-PARC

PRISM/PRIME, EDM ,g-2, Antiproton, NuFactJ

Fast Extraction

Slow Extraction

1ms 100 pulse

0.1s

Kicker

100 Hz is feasible

LOIs are available from :

http://psux1.kek.jp/~jhf-np/LOIlist/LOIlist.html

re-bunch in 50GeV-MRC.Ohmori

It would work. stability?

3.2. PULSED PROTON BEAM 13

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Figure 3.1: A possible layout of the pulsed proton beam facility, consisting of thenear and far facilities.

GeV) and high beam power (more than 0.75 MW) , would give a unique and excellentplace in the world to carry out these physics programs.

At the 50-GeV proton synchrotron, the beam intensity of 3.3 × 1014 proton percycle and a cycle time of 0.3 Hz are planned. When operated in a slow extractionmode, the average beam current and a duty factor are 15 µA and 0.20 respectively.The typical cycle structure at the injection to the J-PARC 50-GeV PS is illustratedin Fig.3.2. Four batches (each of which contains 2 bunches) from the 3-GeV protonsynchrotron are injected into the 50-GeV PS ring when it stays at a low field. When8 buckets out of 10 are filled with beams, the 50-GeV ring starts acceleration. Thelength of every bunch is about 598 nsec (1.67 MHz) and a gap separation is about300 nsec (i.e. 50 % filling). After acceleration to 50 GeV, the pulse width in theJ-PARC 50-GeV proton synchrotron is 6 nsec in sigma. It corresponds to a 3 sigmafull length of about 36 nsec.

3.2.1 Required time structure

The requirements of the time structure of a pulsed beam for the muon and antiprotonphysics programs is different. The requirements will be described in the following.

3.2.1.1 Antiprotons

For efficient capture of antiprotons into a ring, the produced antiprotons have tobe captured via bunch rotation into a storage ring where they will be cooled via

possible layout

design study of the fast extraction kickerspec is almost same as the 50GeV-kicker, but ~10 times faster rise time is required. need idea and study.

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PQRSTUVWXYZ[P\]^W_`] h mm ab 100.0 110.0 110.0PQRSTUVWXYZ[P\]^Wc] w mm ab 100.0 100.0 100.0

d` d mm Nsec*dsec 2530.0 2525.0 2424.0efgShijk dincoil mm ab 15.0 15.0 15.0lmnoijk dsepcoil mm ab 4.0 4.0 4.0

pq Nsec ab 110 101 101PQRSTjk dfer mm ab 19.0 20.0 20.5

_rstijk dmetal mm ab 3.0 4.0 3.0uvwxyz+ droom mm ab 1.0 1.0 0.5|*ijk dground mm ab 7.0 12.0 12.0

d` dsec m dfer+dmetal+droom 23.0 25.0 24.0PQRST~ αfer % dfer/dsec 82.6 80.0 85.4* Z Ω ab 5.0 5.0 5.0PQRST^SY Lfer nH µ0*w*dfer/(2h) 11.93805 11.42397 11.70957

PQRSTvSY Lnon-fer nH !"# 0.90107 1.05334 0.73734SY Lsec nH Lfer+Lnon-fer 12.83912 12.47732 12.44691'+ Csec pF Lsec/Z2 513.5648 499.0927 497.8765

q τ0 nsec Lsec/Z 2.568 2.495 2.489xW$] τ1-99% nsec 4.6*τ0 11.812 11.479 11.451

XZ\sti Ssec mm2 ((dfer+droom-dground)/2)$Csec/(2$ε0) 188508 126828 126519 stiv:v¡¢ asec mm SQRT(Ssec) 434.175 356.129 355.695

£¤Lr VPFN kV ab 40.0 44.0 44.0¥¦§*¨©Lr Vmax kV ab 60.0 60.0 60.0* ZPFN Ω ab 5.0 5.0 5.0ª«¬­PYhS®\­Y ZPFNcable Ω ab 20.0 20.0 20.0¬­PYh¯°±q Ncable % ZPFN/ZPFNcable 4.0 4.0 4.0£¤Lr Vtmc kV VPFN/2 20.0 22.0 22.0

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W¬­PYh$±²³]£¤L´ Itm kA Vtmc/Ztmcable 1.0 1.1 1.1µ¶L´ Ikicker kA Vtmc/Z*2 8.0 8.8 8.8

PQRST^·vXYZ[P\e¸: Bf kG µ0$Ikicker/h 1.00531 1.00531 1.00531PQRST·vXYZ[P\e¸: Bnon-fer kG Bf*Lnon-fer/Lfer 0.07588 0.09269 0.06330

XYZ[P\e¹º¸: Bm kG (Bf$dfer+Bnon-fer$&dmetal+droom))/dsec 0.84367 0.82279 0.86793¸:~ αB % Bm/Bf 83.9 81.8 86.3

»¼y~½¾ (B*d)av T$m Bm*d 0.213448 0.207754 0.210387¿!À8ÁÂÃÄÅ (θ)50GeV mr (B*d)av/(Bρ)50GeV ((Br)50GeV=169.8829) 1.256444 1.222922 1.238424abL´x τcurrent nsec ab 400.000 400.000 400.000L´ÆÇx τround nsec 2*Nsec*τ0 564.921 504.084 502.855

XYZ[P\eÈÉx τtotal nsec τcurrent+τ1-99%+τround 976.733 915.563 914.306

π 3.141592654µ0 Hm-1 1.25664E-06ε0 Fm-1 8.8542E-12µ0/(4$π) 1.0000E-07

0.9 0.8 0.81.2 1.0 1.0

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FNAL case

studied by David Neuffer, WG4 talk yesterday

3

Proton Linac (H-)

2

Proton Driver and Muon beams

• 8GeV Linac can produce streams

of 1.5!1014 8GeV protons at 10Hz

• > 1022 protons/year

• Only 1/15 of these needed for

Main Injector

• Are there muon beam experiments

that could use this intensity ??

• Tertiary muon beams:

• P + X " #

• # " µ + $

• 10-2 µ/p " 1020 µ/year or more

~ 700m Active Length

8 GeV Linac

X-RAY FEL LAB

Slow-Pulse

Spallation Source

& Neutrino Target

Neutrino“Super-

Beams”

Main

Injector

@2 MW

8 GeV

BooNe

NUMI

Anti -

Proton

SY-120

Fixed -

Target

Off -

Axis

Neutrinos to

Homestake …

~ 700m Active Length

8 GeV Linac

X-RAY FEL LAB

Slow-Pulse

Spallation Source

& Neutrino Target

Neutrino“Super-

Beams”

Main

Injector

@2 MW

8 GeV

BooNe

NUMI

Anti -

Proton

SY-120

Fixed -

Target

Off -

Axis

Neutrinos to

Homestake …

Main Injector: 120 GeV, 0.67 Hz Cycle, 2.0 MW Beam Power

Linac Protons: 8 GeV, 4.67 Hz Cycle, 0.93 MW Beam Power

Linac Electrons: 8 GeV, 4.67 Hz Cycle, 0.93 MW Beam Power

8 GeV Linac Cycles 1.5E14 per Pulse at 10Hz

Main Injector Energy

H -

Injection

8 GeV

Protons

8 GeV

Electrons

0

2 0

4 0

6 0

8 0

100

120

140

0 0.5 1 1.5 2 2.5 3

T ime (sec)

MI Energy

H- Injection

8 GeV Protons

Electrons

10

Recycler as accumulator ring ?

• 8GeV Linac produces 1ms

pulses at 10 Hz

• H- injection into Recycler

• 1ms 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

25.4,24.4!x, !yTunes

0.0085"=1/#2-

1/#t2

Slip factor

89.8 kHz

11 $s

f0

T0

Rev. frequency,

Period

8.89 GeV/cPMomentum

3320mC=2%RaveCircumference

But:

Recycler circumference islarge

100ms may be too short atime for bunching

11

Space Charge Difficulty

• Space Charge tune shift:

• Parameters: Ntot=1.5!1014,!N =20" mm-mrad

• MECO: 30ns/1!s : BF= 0.03 !#$ = 4 : too large

• Reduce N to 1.5!1013 !#$ = 0.4

• Reduce N to 0.4!1013 !"# = 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

p tot

2F N

3r N

B!" =

#$ %

F

0.12

B!" =

12

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 oneat a time over ~0.1s

• Uses 1/2 the possible linacpulses (500 bunches/s forPRISM) (100 at 5Hz)

17

Summary

• Muon Beams from the Proton Driver could be very

useful

• Potential muon beam facilities could be developed:

• MECO, PRISM … could be hosted

• More Detailed design needed

• Proton Collection

– Recycler, Accumulator, Debuncher, …

– New Stretcher/Buncher ring ??

• Beam line(s)

• Experimental area(s)

Neuffer’s

Summary

high power proton beam ~1MW- a few MW

pulsed proton beam width ~10ns

single bunch fast extraction

re-bunch in accumulator ring would be necessary

kicker design

These item should be studied for all candidates of NuFact’s proton driver.