1. Main Design Parameters RHIC Magnets for MEIC Ion Collider Ring
New MEIC Design
Main Design Parameters
RHIC Magnets for MEIC Ion Collider Ring
Nov. 6, 2014

2. MEIC Design Goals Y. Zhang, IMP Seminar
Energy (bridging the gap of 12 GeV CEBAF & HERA/LHeC)
Full coverage of s from a few 100 to a few 1000 GeV2
Electrons 3-12 GeV, protons GeV, ions GeV/u
Ion species
Polarized light ions: p, d, 3He, and possibly Li, and polarized heavier ions
Un-polarized light to heavy ions up to A above 200 (Au, Pb)
Up to 2 detectors
Luminosity
Greater than 1033 cm-2s-1 per interaction point over a broad CM region
Maximum luminosity should optimally be around √s=45 GeV
Polarization
At IP: longitudinal for both beams, transverse for ions only
All polarizations >70% desirable
Upgradeable to higher energies and luminosity
20 GeV electron, 250 GeV proton, and 100 GeV/u ion
Y. Zhang, IMP Seminar

3. MEIC Parameters at 5x60 GeV Design Point
Ring circumference m
1450
2200
Proton
Electron
Beam energy
GeV 60 5
Collision frequency
MHz
750
Current / particles per bunch
A / 1010
0.5/0.416
3 / 2.5
0.37 / 0.31
Polarization %
> 70
~ 80
Energy spread
10-4
~ 3
7.1
RMS bunch length mm 10
7.5 12
Horiz./ vert. emittance, norm.
µm rad
0.35 / 0.07
54 / 11
68 / 13.6
Horizontal and vertical β* cm
10 / 2
(4 / 0.8)
12.7 / 2.53
(5 / 1)
Vertical beam-beam tune shift
0.014
0.03
0.017
Laslett tune shift
0.06
Very small
Distance from IP to 1st FF quad
7 (4.5)
3.5
Hour-glass effect
0.96 (0.84)
0.94 (0.79)
Luminosity per IP, 1033
cm-2s-1
5.4 (11.7)
3.1 (6.5)
Numbers in blue font are for a high luminosity detector
Slide 3 3

5. RHIC+(new)High-Field Magnets for MEIC (2.2 km)
Magnet type
RHIC
High field SC
Maximum kinetic energy
GeV
100 (186)
100
Dipole length m
9.45
2.1
Dipole maximum field T
3.4 (4.45)
2.15 6
Dipole bending radius / angle
m / deg
139 / 3.9
155 / 3.5°
55.6 / 2.2°
BDL split
100%
62%
38%
Figure-8 crossing angle
deg
100°
81.7°
FODO cells / dipoles in each arc
72 / 36
23 / 46
FODO cell length / packing factor
29.6 / 0.638
31.6 / 0.73
Arc length / radius
m / m
1065 / 218
731 / 160
Straight length
366
371
Ring circumference
2860
2205
RHIC magnet
9.45 m, up to 2.15 T
High field magnet
2.1 m, up to 6 T

6. RHIC+(new) RHIC-Like Magnets for MEIC (2.2 km)
Magnet type
RHIC
RHIC-like
Maximum kinetic energy
GeV
100 (186)
100
Dipole length m
9.45
4.2
Dipole maximum field T
3.4 (4.45)
2.15
4.45
Dipole bending radius / angle
m / deg
139 / 3.9
155 / 3.5°
75 / 3.2°
BDL split
100%
52%
48%
Figure-8 crossing angle
deg
100°
81.7°
FODO cells / dipoles in each arc
72 / 36
19.5 / 39
FODO cell length / packing factor
29.6 / 0.638
37.4 / 0.73
Arc length / radius
m / m
1065 / 218
729 / 160
Straight length
366
370
Ring circumference
2860
2199
RHIC magnet
9.45 m, up to 2.15 T
New RHIC-like magnet
4.2 m, up to 4.45

7. RHIC+(new) RHIC-Like Magnets: Upgrade to 250 GeV
Magnet type
RHIC
RHIC-like
High-fld
Maximum kinetic energy
GeV
100
250
Dipole length m
9.45
4.2
Dipole maximum field T
2.15
4.45
8.3
Dipole bending radius / angle
m / deg
155 / 3.5°
75 / 3.2°
100 / 5.4°
187 / 1.3°
BDL split
52%
48%
81%
19%
Figure-8 crossing angle
deg
81.7°
FODO cells / dipoles in each arc
19.5 / 39
FODO cell length / packing factor
37.4 / 0.73
Arc length / radius
m / m
729 / 160
Straight length
370
Ring circumference
2199
RHIC magnet
9.45 m, up to 2.15 T
New RHIC-like magnet
4.2 m, up to 4.45 T
Replacing all RHIC magnets by 8.3 T high field SC magnets

8. RHIC+(new) RHIC-Like Magnets: Upgrade to 250 GeV
Magnet type
RHIC
RHIC-like
High-fld
Maximum kinetic energy
GeV
100
250
Dipole length m
9.45
4.2
Dipole maximum field T
2.15
4.45
12.1
Dipole bending radius / angle
m / deg
155 / 3.5°
75 / 3.2°
187 / 2.9°
69 / 7.9°
187 / 1.3°
BDL split
52%
48%
22%
59%
19%
Figure-8 crossing angle
deg
81.7°
FODO cells / dipoles in each arc
19.5 / 39
19.5 / 19.5
FODO cell length / packing factor
37.4 / 0.73
Arc length / radius
m / m
729 / 160
Straight length
370
Ring circumference
2199
Replacing only half RHIC magnets (one of two in a cell) by 12 T high field SC magnets
RHIC magnet
9.45 m, up to 2.15 T
New RHIC-like magnet
4.2 m, up to 4.45 T