1. The MEIC electron ring as the large ion booster
/An old proposition/
Y. Derbenev
MEIC R&D meeting,

2. Prerequisites Two beams/rings about same energy range:
3 to Gev of e-beam in storage ring vs 3 to GeV of protons of Large Booster
Low field warm magnets for e-beam:
MEIC e-ring on PEP-II dipoles (F. Lin):
0.15 T at 5 GeV (0.1 T at 3 GeV)⟶0.65 T at 25 GeV of p
Two beams could share magnets and chamber in arcs while be separated in fig.8 straights:
- First, transport/stack the ion beam to the ion collider ring
- Then inject e-beam from CEBAF to the ring and run the collider

3. PEP-II HER vs. MEIC Arc Cell
Parameters
Unit
PEP-II HER
MEIC TME-like cell (1.5/0.5 pha. adv.)
Energy
GeV 9 12 5
Dipole mag. (phys.) Length m
5.4
5.4 (5.68)
Bending angle
deg
1.875
2.8125
Bending radius
165.0
110.0
Magnetic field T
0.1819
0.3639
0.1516
Quad physical length
0.7185
0.76/0.66/0.66
Field gradient
T/m
5.48
27/28/27
11/12/11
Cell length
15.2
18.36
Number of cell
16*6 96
Number of dipoles
192
Arc length
1459.2
Straight length
Circumference
Nor. emittance um
845
82 (+ 547)
6 (+ 40)
SR power density
total power
kW/m
3.1 (11.31)
2.2 (7.87) MW
2.9 (5.49)
2.0 (3.82)
Sagitta R cm
2.2
3.3
* 40 and 547 um are the contribution of emittance from spin rotator and IR at 5 and 12 GeV, respectively.

4. Issues Quads: need new design/enhancement/construction?
Fast ramp of PEP II magnets: what the additions does it take? (pulse power, etc.)
Finally, is this suggestion sensible and consistent enough to deserve further investigation? – in the view of the overall ongoing explorations of the cost/efficiency optimization.