1. RF Parameters for New 2.2 km MEIC Design
11/13/2014
CASA

2. Staged Operation

3. Electron Ring Parameters
e Ring Input
Electron Ring Parameters
Circumference m
Rev Frequency
0.139
MHz
RF frequency
Harmonic Number
5368
Radius of Dipole
Dipole Bend Angle
2.801
degree
Crossing Angle
81.700
Angle Factor
1.454
Beta Function at RF Cav
5.000
Momentum Compaction
2.142E-03
Bunch Length 12 mm
Linear SR Power Limit 10
kW/m
Total SR Power Limit MW
CavityActiveLength
0.20
Cavity Insertion Length
1.91
temperature
4.2 K
BCS Resistance
215.32 nΩ
Residual Resistance
3.89
Surface Resistance
219.2
Geometric Factor
192.4
R/Q
105.7
Qzero
8.78E+08
Shunt Impedance
9.27E+04 MΩ

4. e Ring Output Parameters
Energy 3 5
7.3 9 12
GeV
gamma
5871.8
9785.7
Current
1.17
3.00
1.31
0.41 A
Energy Spread
2.73E-04
4.55E-04
6.64E-04
8.19E-04
1.09E-03
Phase Slip Factor
2.1E-03
SR power per ring
0.11
2.19
9.93
10.00 MW
Energy Loss per Turn
0.09
0.73
3.31
7.65
24.18
MeV
SR power per unit length
0.109
2.167
9.845
9.911
kW/m
Veff MV
Vpeak
0.47
2.23
7.35
14.49
37.88
Syn. Phase
11.70
19.05
26.76
31.87
39.66
degree
Vgap
0.45
0.35
0.69
1.80
Gradient
2.3
2.2
1.7
3.4
9.0
MV/m
Syn. Tune
0.017
0.028
0.041
0.050
0.067
Power fed to beam per Cavity
110.2
437.2
473.0
476.2 kW
Forward Power
155.1
466.4
480.3
482.1
482.2
Cavity Power Loss
2.1
1.3
5.1
35.1 W
Reflected Power
45.0
29.1
6.0
Coupling Beta
1.57E+05
3.39E+05
4.59E+05
1.16E+05
1.70E+04 δf
-97.0
-251.2
-302.6
-63.6
-7.0
kHz
Qext
5.58E+03
2.59E+03
1.91E+03
7.57E+03
5.17E+04
Qloaded
Long. SR Damping Time
227.82
49.21
15.81
8.44
3.56 mS
Tran. SR Damping Time
455.64
98.42
31.62
16.88
7.12
Active Cavity Number 1 21

5. Ion Collider Bunch Cavities Parameters
Particle
Proton
Lead ion
Energy
100 40
GeV/u
Rev Frequency
0.139
MHz
gamma
107.6
44.1
RF frequency
Current
0.50 A
Harmonic Number
5368
Circumference m
Momentum Compaction
6.413E-03
Energy Spread
2.00E-04
Bunch Length 12 mm
Phase Slip Factor
6.3E-03
5.9E-03
CavityActiveLength
0.200
Vpeak
24.09
22.79 MV
Cavity Insertion Length
1.91
Syn. Phase
0.00
degree
temperature
4.2 K
Vgap
1.85
1.90
BCS Resistance
215.32 nΩ
Gradient
9.252
9.482
MV/m
Residual Resistance
3.89
Syn. Tune
0.036
0.034
Surface Resistance
219.2
Forward Power
92.55
194.41 kW
Geometric Factor
192.36
Cavity Power Loss
37.0
38.9 W
R/Q
Reflected Power
92.5
194.4
Qzero
8.78E+08
Coupling Beta
1.00E+04
2.00E+04
Shunt Impedance
9.27E+04 MΩ δf
-10.7
-10.4
kHz
Qext
8.78E+04
4.39E+04
Qloaded
8.77E+04
Active Cavity Number 13

6. Low Frequency RF Cavities
Booster H+
Circumference
234 m
Energy
0.28 ~ 8
GeV
Harmonic Number 1
Frequency Range
0.817
1.274
MHz
Gaps per Cavity 2
Ramping Time
0.396
Sec
Cavity Number
Vgap
8.0 kV
Cavity Length
2.2
Beam Power kW
Total Cavity Length
4.4
Power Loss per Cavity
41.2
Ferrite Toroid Inner Radius
0.25
Ferrite Toroid Outer Radius
0.5
Ferrite Stack Length
Maximum Vgap 10
Collider
2149.9
100 9
1.248
1.255
12.002 7
7.9
27.5
15.4
23.6

7. Used PEP-II 476 MHz Cavities for MEIC Collider Rings
The Number of Cavities 36
Shunt Impedance ()
7 MW (V2/P) Q0
31000
Coupler Beta
3.5 ~ 4.0
Maximum Vgap
1 MV
Maximum Pfwd per Cavity
400 kW
The Number of Klystrons 15
Strategy:
Split cavities and klystrons in two rings with different cavity/Klystron ratio;
Build a couple of new cavities if necessary upfront;
Build new 952 MHz cavities in the future to gradually replace 476 MHz cavities

8. 476 MHz Cavities in Collider Rings for Bunch Length of 12 mm
(GeV) I
(A)
Vgap (MV)
Pforward (kW)
Pcavity (kW)
Cavity Number b
Klystron Number
Energy Spread
e Ring
8.7
1.10
0.78
395 87 24
3.93 12
7.92e-4 8
1.24
0.76
398 82 19 10
7.28e-4 7
1.38
0.73
384 77 13
3.90
4.37e-4 6
1.75
0.66
374 62 9
3.96 5
5.46e-4
2.30
0.57
370 46
3.94 3
4.55e-4
Ion Ring 29
0.5
0.79
128 88
3.5 2 36
125 86 16 50
118
100
129 89 48
2e-4

9. Working Point in e Ring