SuperB Meeting, May 2008 SuperB Meeting, May 2008 Status Status of the magnetic design of of the magnetic design of the first quadrupole (QD0) the first quadrupole (QD0) for the Super for the Super B B interaction interaction region region S. Bettoni on behalf of the whole team S. Bettoni on behalf of the whole team (S. Bettoni, M.E. Biagini, E. Paoloni, P. Raimondi) (S. Bettoni, M.E. Biagini, E. Paoloni, P. Raimondi)
Status of the magnetic design of the first quadrupole (QD0) for the Super B interaction region. S. Bettoni on behalf of the whole team (S. Bettoni, M.E. Biagini , E. Paoloni , P. Raimondi). SuperB Meeting, May 2008. Outline. Introduction The Super B interaction region - PowerPoint PPT Presentation
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SuperB Meeting, May 2008SuperB Meeting, May 2008
StatusStatus
of the magnetic design of the of the magnetic design of the
first quadrupole (QD0) first quadrupole (QD0)
for the Superfor the SuperBB interaction interaction
regionregionS. Bettoni on behalf of the whole teamS. Bettoni on behalf of the whole team
(S. Bettoni, M.E. Biagini, E. Paoloni, P. Raimondi)(S. Bettoni, M.E. Biagini, E. Paoloni, P. Raimondi)
IntroductionIntroduction The SuperThe SuperBB interaction region interaction region
Why the siamese twins QD0 are auspicious for the SuperWhy the siamese twins QD0 are auspicious for the SuperBB IR IR
The conceptual design (2D) of the siamese twins QD0The conceptual design (2D) of the siamese twins QD0 How to generate a perfect multipoleHow to generate a perfect multipole
Quadrupoles cross talk: how to compensate itQuadrupoles cross talk: how to compensate it
The 3D magnetic modelsThe 3D magnetic models At a fixed wire properties (J, dimensions): At a fixed wire properties (J, dimensions):
• Winding shape optimization (gradient and field quality)Winding shape optimization (gradient and field quality)• Determination of the working pointDetermination of the working point
Study of the configuration with the 7/4 gradients ratioStudy of the configuration with the 7/4 gradients ratio
ConclusionsConclusions
Outline
The IP region in the SuperB
IPIP
SuperSuperBB strategy to reach high luminosity (10 strategy to reach high luminosity (103636 cm cm-2-2ss-1-1) relies on:) relies on:
Strong final focusing Strong final focusing
Large crossing angle ( ~2 x 25 mrad )Large crossing angle ( ~2 x 25 mrad )
Final doublet (QD0 + QF1)Final doublet (QD0 + QF1)
Close to the IP to minimize chromaticityClose to the IP to minimize chromaticity
Excellent field qualityExcellent field quality
IPIP
QD0QD0
QF1QF1
Possible optionsOption 1Option 1
QD0 shared among QD0 shared among
both both
HER and LERHER and LER
Option 2Option 2
Twin quadrupoles:Twin quadrupoles:
both beams on axisboth beams on axis
QD0
IPQD0
-10
-8
-6
-4
-2
0
2
4
6
8
10
-5 -4 -3 -2 -1 0 1 2 3 4 5
x (cm)
By (T
)
-10
-8
-6
-4
-2
0
2
4
6
8
10
-5 -4 -3 -2 -1 0 1 2 3 4 5
x (cm)
By (T
)
Option 1: QD0 shared among HER and LER
Very thick (expensive) tungsten shielding needed Very thick (expensive) tungsten shielding needed
Current DensityCurrent DensityCurrent DensityCurrent Density
*
-0.01-0.005
00.005
0.01
-0.01
-0.005
0
0.005
0.010
2
4
6
8
10
12
xy
z
-0.01-0.005
00.005
0.01
-0.01
-0.005
0
0.005
0.010
2
4
6
8
10
12
xy
z
-0.01-0.005
00.005
0.01
-0.01
-0.005
0
0.005
0.010
2
4
6
8
10
12
xy
z
-5 0 5
x 10-3
-0.1
-0.05
0
0.05
0.1
x (m)
By (
T)
y = - 0.51*x3 + 0.0068*x2 + 17*x - 2.6e-005
Simulated values cubic
The ideal quadrupole
-5 0 5
x 10-3
0
0.5
1
1.5
2
2.5x 10
-7
x-xC
(m)
By-b
1.x (
T)
-5 0 5
x 10-3
0.005
0.01
0.015
0.02
0.025
0.03
x (m)
By (
T)
y = 1e+004*x3 + 1.6e+002*x2 + 1.7*x + 0.014
Simulated values cubic
Relative intensity @ x = ±5 mm
B2/B1
B3/B1
z center
1.40E-02
-4.10E-02
The winding shape
AML-like single AML-like single Perfect QuadrupolePerfect Quadrupole
Siamese TwinSiamese TwinQuadrupoleQuadrupole
J ()
z
Starting from the principle of the AML ideal multipolar
magnet optimize the winding shape to produce an ideal
quadrupolar field centered on each of the beams
Two counter rotating windings to cancel out the inner
solenoidal field and the outer field generated by the magnet
centered on the close beam.
→
How the analysis is performedFor each winding the field quality at several z and the maximum field in the conductor are For each winding the field quality at several z and the maximum field in the conductor are
determineddetermined
The winding shape optimization
SCAN NUMBER
VariedVaried The radius of curvature of the windingsThe radius of curvature of the windings The step of the windingsThe step of the windings
To maximizeTo maximize The field quality at the beginning/end of the windingsThe field quality at the beginning/end of the windings The ratio gradient/maximum field on the conductorThe ratio gradient/maximum field on the conductor
The winding shape: the field quality
0 1 2 3 4 5 6 7 8-0.5
0
0.5
1
1.5
2
2.5
3x 10
-4
Scan #
b0(T
)
Central z
Starting z
0 1 2 3 4 5 6 7 80
5
10
15
20
25
30
35
Scan #
b1(T
/m)
Central z
Starting z
0 1 2 3 4 5 6 7 8-20
-15
-10
-5
0
5
10
Scan #
b2(T
/m2 )
Central z
Starting z
0 1 2 3 4 5 6 7 8-250
-200
-150
-100
-50
0
50
100
150
200
250
Scan #
b3(T
/m3 )
Central z
Starting z
The winding shape: the field quality
0 1 2 3 4 5 6 7 8-0.5
0
0.5
1
1.5
2
2.5
3x 10
-4
Scan #
b0(T
)
Central z
Starting z
0 1 2 3 4 5 6 7 80
5
10
15
20
25
30
35
Scan #
b1(T
/m)
Central z
Starting z
0 1 2 3 4 5 6 7 8-20
-15
-10
-5
0
5
10
Scan #
b2(T
/m2 )
Central z
Starting z
0 1 2 3 4 5 6 7 8-250
-200
-150
-100
-50
0
50
100
150
200
250
Scan #
b3(T
/m3 )
Central z
Starting z
2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8-1.6
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
Scan #
b2(T
/m2 )
Central z
Starting z
2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8-20
0
20
40
60
80
100
120
140
Scan #
b3(T
/m3 )
Central z
Starting z
The winding shape: |B|MAX in the conductor
1 2 3 4 5 6 70.44
0.46
0.48
0.5
0.52
0.54
Scan #
|B| M
AX (
T)
The winding shape: the conclusion
Relative intensity @ x = ±5 mm
B2/B1
B3/B1
|B|MAX (T)
Scan 7
z center z start
-2.72E-05 -1.36E-05
1.33E-05 1.52E-050.517
Scan 4
z center z start
-7.74E-05 -6.28E-05
-1.09E-05 -9.25E-060.502
Scan 7 more advantageous than scan 4:Scan 7 more advantageous than scan 4: Better field quality in the majority of the winding along the z-axis and acceptable Better field quality in the majority of the winding along the z-axis and acceptable
at the endat the end
Larger radius of curvature (better for degradation and mechanics)Larger radius of curvature (better for degradation and mechanics)
Scan 4 more advantageous than scan 7:Scan 4 more advantageous than scan 7: Maximum field in the conductor slightly lowerMaximum field in the conductor slightly lower
QD0 shared by HER and LER would produce backgrounds (synchrotron radiation and off-QD0 shared by HER and LER would produce backgrounds (synchrotron radiation and off-
energy leptons over-bending)energy leptons over-bending)
One QD0 for each ring would allow to reduce/solve the problemOne QD0 for each ring would allow to reduce/solve the problem
Up to now:Up to now: A good field quality has been obtained both in the central part of the coil and at the endA good field quality has been obtained both in the central part of the coil and at the end The winding shape has been optimized to maximize the gradient and improve the field qualityThe winding shape has been optimized to maximize the gradient and improve the field quality
For the future:For the future: Dimensioning of the coil according to the SuperB IR requests and maximization of the gradientDimensioning of the coil according to the SuperB IR requests and maximization of the gradient A first try to produce a configuration with the gradients in ratio 7/4 is under optimizationA first try to produce a configuration with the gradients in ratio 7/4 is under optimization Recently proposed a method to move the magnetic axis of the quads along z axis (work in Recently proposed a method to move the magnetic axis of the quads along z axis (work in
progress)progress) Mechanical feasibilityMechanical feasibility Cryogenic systemCryogenic system
Extra slides
Last presented coil (BINP Meeting-April 2008)
• @ j = 500 A/mm2 Bmax< 0.56T
E. Paoloni
Relative intensity @ x = ±5 mm
B2/B1
B3/B1
z center
4.44E-05
7.26E-05
The possible dimensions of the coils
xENTR = 1 cm
ENTR = 110 m
xEXIT = 2 cm
EXIT = 0.23 mmx for the beam→
0 0.4 1.9 3.4
-3
-2
-1
0
1
2
3
x (cm)
y (c
m)
0
5
10
15
20
25
30
35
40
45
1 1.5 2 2.5
Gra
dien
t (T/
m)
Inner radius (cm)
Simulated points
R = 1.5 cm
Fixed J
The end
Field in & out
For unitary radius and imposing 0/2 = 1
Source: infinite Source: infinite wire parallel to zwire parallel to z
Field point outside Field point outside circlecircle
Field point Field point inside circleinside circle
E. Paoloni
COIL LCOIL L COIL RCOIL R
Inside R + Outside LInside R + Outside LInside L + Outside RInside L + Outside R