OPTIMIZED SOLENOID BASED CAPTURE MECHANISM FOR A...

OPTIMIZED SOLENOID BASED CAPTURE MECHANISM FOR A MUON COLLIDER/NEUTRINO FACTORY TARGET SYSTEMMUON COLLIDER/NEUTRINO FACTORY TARGET SYSTEM

HISHAM KAMAL SAYEDBROOKHAVEN NATIONAL LABORATORY

MAP COLLABORATION MEETING, FERMILAB, June 20 2013

INTRODUCTION & LAYOUT2

Muon Capture in Target & Front END

Capture Solenoid Field Study: Optimizing quantity: Muon (Pions) count – transverse capture

- Target Solenoid peak fieldg p- Final end field

Optimizing quality: Muon (Pions) longitudinal phase space (transverse-longitudinal coupling) – transverse-longitudinal capturelongitudinal coupling) transverse longitudinal capture - Taper field profile

Optimizing the time of flight of incident beam (Buncher Rotator RF phase) Optimizing the time of flight of incident beam (Buncher-Rotator RF phase) Transverse focusing field in decay-channel-buncher-rotator Match to ionization cooling channel for every end field case 1.5 T 3.5 T P f f f t d f ti f t b h l th Performance of front end as a function of proton bunch length Realistic Coil Design & performance optimization

Hisham Sayed - MAP meeting 20136/20/13

MUON COLLIDER/NEUTRINO FACTORY LAYOUT3

Target System Solenoid:C t ± f i 100 400 M V f 4 MW t b (E 8 G V)Capture ± of energies ~ 100-400 MeV from a 4-MW proton beam (E ~ 8 GeV).


TARGET SYSTEM CURRENT BASELINE DESIGNSC magnets

4

Production of 1014 /s from 1015 p/s ( 4 MW proton beam)

Proton beam readily tilted with respect to magnetic

SC magnets

Tungsten beads

Proton beam readily tilted with respect to magnetic axis.

Shielding of the superconducting magnets from radiation is a major issue.

Proton beam andMercury jet

H T t

Resistive magnets

Hg Target Proton Beam

E=8 GeV S l id Fi ld

Mercury collection poolWith splash mitigator

5-T copper magnet insert; 10-T Nb3Sn coil + 5-T NbTi outsert.Desirable to eliminate the copper magnet (or replace by a 20-T HTS insert).

Solenoid Field IDS120h 20 T peak field at target position (Z=-37.5) Aperture at Target R=7.5 cm - End aperture R = 30 cm Fixed Field Z = 15 m Bz=1.5 T Fixed Field Z 15 m Bz 1.5 T

Production: Muons within energy KE cut 40-180 MeV end of decay channel

Nμ+π+κ/NP=0.3-0.4


TAPERED TARGET SOLENOID OPTIMIZATION5

Inverse-Cubic TaperBz (0, zi z z f ) B1

[1 a1(z z1) a2 (z z1)2 a3(z z1)3]p

B ' (B / B )1/p 1 2a (B / B )1/ p 1 aa1 B1

pB1

a2 3(B1 / B2 ) 1(z2 z1)2 2a1

z2 z1

a3 2 (B1 / B2 ) 1(z2 z1)3 a1

(z2 z1)2

(2n)( )

Off-axis field approximation Br (r, z) (1)n1

n a0

(2n1)(z)(n1)(n!)2 ( r

2)2n1

Bz (r, z) (1)n

n a0

(2n)(z)(n!)2 ( r

2)2n

a0(n) dna0

dzn dnBz (0, z)

dzn

1.5 T 2.5 T 3.5 T

1 5 T 2.5 T 3.5 T1.5 T

6/20/13 Hisham Sayed - MAP meeting 2013

MARS SIMULATIONS & TRANSMISSION6

MARS1510 Simulation:Counting muons at 50 m with K.E. 80-140 MeV

rfinal =30

Rini=7.5-10 cm

Bi=20-15 T

0.42

0 cm

Bi 20 15 T

0.4

0.41

0.38

0.39

N[m

uons

]/N[p

]

0.35

0.36

0.37

Bz=20 -> 1.5 T15 -> 1.5 T

15 -> 1.66 T15 -> 1.8 T

0.35 500 1000 1500 2000 2500 3000 3500 4000 4500

Z d [ ]

Ltaper [cm]Hisham Sayed - MAP meeting 20136/20/13

LONGITUDINAL PHASE SPACE DISTRIBUTIONS (SHORT VERSUS LONG TAPER)7

Long adiabatic taper 40 mEnd of taper End of Decay

Short taper 4 m


PHASE SPACE DISTRIBUTIONS (SHORT VERSUS LONG TAPER)8

T-Pz Correlations at end of decay channelLong Solenoid taper: More particles More dispersed (misses the buncher acceptance windows)

Short Solenoid taper: more condensed distributions that fits more particles within the buncher acceptance windows

Short TaperLong Taper

more condensed distributions that fits more particles within the buncher acceptance windows


PHASE SPACE DISTRIBUTIONS (SHORT VERSUS LONG TAPER)9

Short Taper 4 mLong Taper 40 m

T-Pz phase space at end of decay channel

Short Taper 4 mLong Taper 40 m

Long Solenoid taper: More particles More dispersed (misses the buncher

Short Solenoid taper: Higher density t-pz distribution


More dispersed (misses the buncher acceptance windows) Fits more particles within the

acceptance of buncher/rotator

PHASE SPACE - SHORT VERSUS LONG TAPER10

0 8

1

Bz=20-1.5 z=50 m

Ltaper=4.00 GoodLtaper=40.00 GoodShort Taper

T-Pz Correlations at end of decay channel of good particles

Green: Initial distribution of good particles which b h d d l d i 4D li h l

0.6

0.8

[GeV/c]

Long Taperwere bunched and cooled in 4D cooling channel

0.2

0.4

Pz

0 160 180 200 220 240 260 280 300

T [nsec]

Tape

r

ng T

aper

Shor

t T

Lon

Good Particles


PERFORMANCE DEPENDENCE ON TIME OF FLIGHT (RF PHASE)11

1200

1400

1600

1800t=2.044e-09 sect=2.544e-09 sect=3.044e-09 sect=3.544e-09 sect=4.044e-09 sec

t=4.544e-09 sec -BSLINEt=5 044e 09 sec

0.06

0.07

0.08MARS1015 2012

OLDOLD

0 cm

‐75 cm

600

800

1000

1200 t=5.044e-09 sect=5.544e-09 sect=6.044e-09 sect=6.544e-09 sec

0.03

0.04

0.05

rotons at z=‐200

A Proton

s at z=‐

0

200

400

0 2 4 6 8 10 0

0.01

0.02

5 0 5 10 15

TOA P

TOA

Time [nsec]-5 0 5 10 15

10000

12000TOA=5.38012e-09TOA=4.88014e-09TOA=3.88019e-09TOA=2.88023e-09

8000

9000

6000

8000

n+/proton

TOA=1.88028e-09TOA=1.3803e-09TOA=8.80321e-10TOA=3.80343e-10TOA=-6.19613e-10TOA=-1.61957e-09TOA=-2.11955e-09 5000

6000

7000Muon "output.all.dat" u 2

Optimizing RF Phase

2000

4000Muo TOA=-3.1195e-09TOA=-4.11946e-09

3000

4000

5000

Hisham Sayed ‐MAP meeting 20136/20/13

0 0 50 100 150 200 250 300 350

z [m] 2000

0 5 10 15 20 25 30 35Iteration

FRONT END PERFORMANCE12

Using baseline cooling section Using longer cooling sectiong g(140 cooling cell)

Using longer cooling section (200 Cooling cell)

0 11

0.12Bz=20-1.5TBz=15-1.5T 0 12

0.125Bz=20-1.5TBz=15-1.5T

0.08

0.09

0.1

0.11

oton

5 .5Bz=15-2.5T

0 105

0.11

0.115

0.12

oton

5 .5Bz=15-2.5T

~ 30%

0.05

0.06

0.07

Muon/pro

0.095

0.1

0.105

Muon/pro 30%

~ 30%

0.02

0.03

0.04

0 5 10 15 20 25 30 35 40 0.08

0.085

0.09

0 5 10 15 20 25 30 35 40

30%

Taper Length [m] Taper Length [m]

High statistics tracking of Muons through the front end


FRONT END PERFORMANCE13

Using longer cooling section (200 Cooling cell)

High statistics tracking of Muons through the front end


MUON YIELD VERSUS END FIELD & BUNCH LENGTH14

0.14Bz(Target)=15 T

0.16Bunch length=0 nsec

Muon yield versus end field Muon yield versus Proton Bunch Length

B (T ) 20 T

0.13

0.135

ton

Bz(Target)=15 TBz(Target)=20 T

0.145

0.15

0.155

ton

Bz(Target)=20 T20% for every 1 T incerease in

constant field

0.12

0.125

Muon+/prot

0.13

0.135

0.14

Muon+/prot

0.11

0.115

M

0.115

0.12

0.125

M

Baseline0.11

0 0.5 1 1.5 2 2.5 3Proton Bunch Length [nsec]

0.115 1.5 2 2.5 3 3.5

Constant Bz [T]

Performance of FE as function of Constant solenoid filed in Decay

~ 3% loss per 1 nsec increase in bunch lengthConstant solenoid filed in Decay

Channel – Buncher – Rotator (matched to +/- 2.8 T ionization cooling channel)

length


NEW SHORT TARGET CAPTURE REALISTIC MAGNET (WEGGEL)15

Muon Target Capture MagnetDecay channel Triplet

Taper Magnets

Short Taper length =7 m- B=20-1.5 TOn axis field [scale /20 T]

p

Target MagnetsTarget Magnets

Decay channel Triplet

Taper Magnets

On axis field [scale /20 T]Muon Target Capture Magnet

Short Taper length =5 m- B=20-2 5 T

Target Magnets

Short Taper length 5 m- B 20-2.5 T

7/25/2013 Hisham Sayed BNL

NEW SHORT TARGET CAPTURE MAGNET (WEGGEL)16

Muon Target Short Taper Magnet taper length =7 m- B=20-1.5 & 2.5 T

Bz [T]

1214161820

4 6 8 10 12 14 16 1820

Bz [T]

0 0 15 0.2 0.25

0.3

0 2 4 6 81012

0 24

0 5 10 15 20 25Z [m] 0 0.05

0.10.15R [m]

Target SC Magnets Field Map calculated f li i ilfrom realistic coils

Engineering (V. Grave)IDS120_20-1.5T7m2+5 Cryo 1


NEW DECAY CHANNEL REALISTIC MAGNET (WEGGEL)17

The pions produced in the target decay to muons in a Decay Channel (50 m)Three superconducting coils (5-m-long ) Bz(r=0) ~ 1.5 or 2.5 T solenoid field.Suppress stop bands in the momentum transmissionSuppress stop bands in the momentum transmission.

1.55

1.67 m 5 m

1.45

1.5

1.35

1.4

IDS120L20-1.5T 7m

0 2 4 6 8 101.3

Magnet Length [m] Inner R [m] Outer R [m] J [A/mm2]

1 0.19 0.6 0.68 47.18

2 3.8 0.6 0.63 40.00Axial-field profile of two Decay-Channel modules


3 0.19 0.6 0.68 47.18

REALISTIC COIL BASED DECAY CHANNEL SOLENOID STOP BANDSTUDY

18

Suppression of stop bands in the Decay Channel:Tracking muons through decay channel 10 cells (50 m) optimize magnet design for best performance

Transmission:Constant 1.5 Solenoid Field %67 IDS120L20to1.5T7m %62Modified IDS120L20to1 5T7m %66Modified IDS120L20to1.5T7m %66

1000Modified 1.5 T Channel v02

IDS120L20to1.5T7m IDS120L20to1.5T7m 800

1.5 T constant solenoid fieldField generated from Coils

700

800

900Modified 1.5 T Channel v02

1.5 T Channel v02

500

600

700

Field generated from Coils

300

400

500

600

N

300

400

500

Muon

0

100

200

300

100

200

Optimization


0 0.05 0.1 0.15 0.2 0.25 0.30.350.40.450.50.55P [GeV/c]

0 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55

Ptot [GeV/c]

CONCLUSION & SUMMARY19

1- Target Solenoid parameters that affect the particle Capture & Transmission at target or after cooling

Initial peak Field – Taper length – End Fieldp p g2- Impact:Short taper preserves the longitudinal phase-space muons can be captured efficiently in the

buncher-phase rotation sections and more muons at the end of cooling.The maximum yield requires taper length of 7-5 m for all cases (20-15T) (1.5-3.5T) for anybunch length.

3- Final constant end field increases the yield by 20% for every 1 T increase in the field beyond the 1.5 T baseline

4 I i i l b h l h i fl h / i ld h d f h li h l4- Initial proton bunch length influence the muon/proton yield at the end of the cooling channel ~ 3% reduction per 1 nsec increase in bunch length.

5 R li ti C il d i5- Realistic Coil design.

Hisham Sayed ‐MAP meeting 20136/20/13

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