Transcript MUON TARGET PARTICLE PRODUCTION STUDY: TAPERED FIELD PROFILE HISHAM KAMAL SAYED Physics Department Brookhaven National Lab July 3, 2012

MUON TARGET PARTICLE PRODUCTION
STUDY:
TAPERED FIELD PROFILE
HISHAM KAMAL SAYED
Physics Department
Brookhaven National Lab
July 3, 2012
Hisham Kamal Sayed BNL
Ding’s Optimized Parameters
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Hg Target
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θTarget = 0.137 rad
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Rtarget = 0.404 cm
Proton Beam
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E = 8 GeV
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θBeam = 0.117 rad
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x = σy = 0.1212 cm (Gaussian Distribution)
Solenoid Field
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IDS120h  20 T peak field at target position (Z=0)
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Aperture at Target R = 7.5 cm - End aperture R = 30 cm
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Fixed Field Z = 1862.0  Bz = 1.5 T
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Production: Muons within energy KE cut 40-180 MeV
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3.27 X 104 (Nini =105)
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Hisham Kamal Sayed BNL
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Target Particle Production with 15 T Peak
Solenoid Field
Particle Capture requirement (Pt ~ 0.225 GeV/c)
Br = 20 T X 7.5 cm = 150 T cm ----Br = 15 T X 10 cm = 150 T cm
Fixed flux requirement (Aperture Requirement)
Br2 = 20 X 7.52=1125 T cm2 ------ Br2 = 15 X 102 =1500 T cm2
MARS simulations with 15 T peak field & new aperture settings (Taper R = 1030 cm)
2.5
2
1.5
Bz [T]
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1
0.5
0
600
800
1000
1200
1400
Z [cm]
1600
1800
2000
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Hisham Kamal Sayed BNL
11/6/2015
Muon Production IDS120h 15 T
Bz=1.85T
Bz=2.12T
Bz=2.5T
Bz=1.7T
Bz=1.667T
Bz=1.667T
Bzpeak = 20 T
Zend =1862
Bzend =1.5 T
Bz=1.667T
Bz=1.667T
Bz=1.5T
Bz=1.5T
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Hisham Kamal Sayed BNL
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Analytic form for Tapered Solenoid
(K. McDonald)
 Inverse-Cubic Taper
Bz (0, zi < z < z f ) =
a1 = -
B1'
pB1
a3 = -2
B1
[1+ a1 (z - z1 ) + a2 (z - z1 )2 + a3 (z - z1 )3 ]p
(B1 / B2 )1/ p -1 2a1
a2 = 3
(z2 - z1 )2
z2 - z1
(B1 / B2 )1/ p -1
a1
+
3
(z2 - z1 )
(z2 - z1 )2
Off-axis field approximation
a0(2n) (z) r 2n
Bz (r, z) = å (-1)
( )
(n!)2 2
n
n
Br (r, z) = å (-1)
n
a0(n) =
n+1
a0(2n+1) (z) r 2n+1
( )
(n +1)(n!)2 2
d a0 d n Bz (0, z)
=
dz n
dz n
n
Field at R=0
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Hisham Kamal Sayed BNL
MARS RESULTS
 Beam Pipe with constant R = 30 cm
 Beam Pipe material changed to blackhole to speed
calculations
 Added subroutine to m1510.f (FIELD) to calculate the field
using inverse cubic equations
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Inverse Cubic Field(P = 1)
MARS simulation results:
Counting muons at 50 m with K.E. 80 -140 MeV
0.42
0.41
N[muons]/N[p]
0.4
0.39
0.38
0.37
Bz=20 -> 1.5 T
15 -> 1.5 T
15 -> 1.66 T
15 -> 1.8 T
0.36
0.35
500
1000
1500
2000
2500
Zend [m]
3000
3500
4000
4500
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