1. Feasibility of Reusing PEP-II Hardware for MEIC Electron Ring
Fanglei Lin, Andrew Hutton, Leigh Harwood, Vasiliy Morozov, Fulvia, Pilat, Yuhong Zhang
F. Lin

2. FODO Arc Cell Aperture radius 45 mm Dipoles Quadrupoles  
Magnetic/physical length 5.4/5.68 m
Bending angle 40.9 mrad (2.34), bending radius 132 m
GeV, GeV
Sagitta 2.8 cm
Quadrupoles
Magnetic/physical length / m
-11 and 14 T/m field 12 GeV
for 135/90 x/y betatron phase advance
mm radius
Sextupoles
Magnetic/physical length 0.25/0.31 m
-172 and 94 T/m2 field 12 GeV
0.17 and mm radius
BPMs and Correctors
Each one physical length 0.15 m
Complete FODO
Length 15.2 m
Arc bending radius 186 m
optimal curvature  

3. TME-like Arc Cell Aperture radius 45 mm Dipoles Quadrupoles Sextupoles
Magnetic/physical length 5.4/5.68 m
Bending angle 55.9 mrad (3.2), bending radius 96.5 m
GeV, GeV
Sagitta 3.8 cm
Quadrupoles
Magnetic/physical length 0.9/0.96 and / m
19.2, and T/m field 12 GeV
for 270 and 90 x/y betatron phase advance
0.87, and mm radius
Sextupoles
Magnetic/physical length 0.25/0.31 m
-381 and 361 T/m2 field 12 GeV/c
0.39 and mm radius
BPMs and Correctors
Each one physical length 0.15 m
Complete FODO
Length m
Arc bending radius 183 m

4. PEP-II HER vs. MEIC Arc Cell
Parameters
Unit
PEP-II HER FODO cell
MEIC FODO cell (135/90 pha. adv. )
MEIC FODO cell (90 pha. adv. )
MEIC TME-like cell (1.5/0.5 pha. adv.)
Energy
GeV 9 12
Dipole physical length m
5.68
Bending angle
deg
1.875
2.34
3.205
Bending radius
165.0
132
96.5
Magnetic field T
0.1819
0.3030
0.4147
Sagitta R cm
2.2
2.8
3.8
Quad physical length
0.7185*
0.7785/0.7785
0.96/0.7785/0.7785
Field gradient
T/m
5.48*
14/11
10.7/10.6
19/19/18
Cell length
15.2
20.444
Number of cells 96
104 76
Number of dipoles
192
208
152
Number of quads
192 (?)
104/104
76/152/152
Norm. emittance um
845
513 (+ 547*)
1175 (+ 547)
94 (+ 547)
SR power density
total power
kW/m 10 MW
10.4
* m is the magnetic length shown in the conceptual design report. It has 70 quadrupole magnets of this type.
* 547 um is the contribution of emittance from the spin rotators and interaction regions at 12 GeV. This can be further optimized.

5. PEP-II HER vs. MEIC Arc Cell
Parameters
Unit
PEP-II HER FODO cell
MEIC FODO cell (135/90 pha. adv. )
MEIC FODO cell (90 pha. adv. )
MEIC TME-like cell (1.5/0.5 pha. adv.)
Energy
GeV 9 12
Dipole physical length m
5.68
Bending angle
deg
1.875
2.34
3.205
Sagitta R cm
2.2
2.8
3.8
Quad physical length
0.7185*
0.7785/0.7785
0.96/0.7785/0.7785
Field gradient
T/m
5.48*
14/11
10.7/10.6
19/19/18
Cell length
15.2
20.444
Norm. emittance um
845
555 (+ 547*)
1175 (+ 547)
94 (+ 547)
Hor. Max. beam size with *=(10,2)cm mm
4.3
5.4
3.3
Hor. Max. beam size with *=(40,8)cm
2.7
1.6
Such large beam demands large dynamic aperture.
This is the beam size at 12 GeV. Beam size will be double at 20 GeV !
Luminosity reduces by a factor of 4

6. Thank You for Your Attention !

7. MEIC e-ring Geometry e- Whole ring 2510.6 m Each arc 879.9 m
Each straight m
Each arc m
Whole ring m