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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).
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
FRONT END PERFORMANCE13
Using longer cooling section (200 Cooling cell)
High statistics tracking of Muons through the front end
Hisham Sayed - MAP meeting 20136/20/13
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
Hisham Sayed - MAP meeting 20136/20/13
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
7/25/2013 Hisham Sayed BNL
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
7/25/2013 Hisham Sayed BNL
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
7/25/2013 Hisham Sayed BNL
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