MEIC Ion Injector Complex Present Status
Alex Bogacz
MEIC Collaboration Meeting, Jefferson Lab, March 30-31, 2015
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
1
MEIC Complex - Baseline Layout
Electron-Ion
Collider
Rings
IP
3-10 GeV
8 to100 GeV
8 GeV Booster
Future IP
SRF Linac to 285 MeV
Ion Sources
Electron Injector
3-10 GeV
Hall D
12 GeV CEBAF
5.5-pass CW RLA
Halls A, B, C
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
2
Ion Injector Complex - Overview
8 GeV Booster
SRF Linac to 285 MeV
Ion Sources
Present status of the ion injector complex:
Relies on demonstrated technology for injectors and ion sources
Adopted an SRF linac design (al FRIB)
8 GeV Booster design avoiding transition crossing with all ion species
Injection/extraction transfer lines to/from the Booster have been designed
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
3
Evolution of Beam Parameters: Polarized Protons
(units)
*ABPIS
Source
Linac
Booster
Entrance
Injection
Extraction
H-
H-
H- ￫ H+
H+
~0
13.2
285
7062
g
1.3
8.52
b
0.64
0.993
Charge status
Kinetic energy
MeV
Pulse current
mA
2
2
2
Pulse length
ms
0.5
0.5
0.22
Charge per pulse
μC
1
1
0.44
Protons per pulse
1012
3.05
3.05
2.75
Pulses
1
*ABPIS - Atomic Beam Polarized Ion Source
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
4
Evolution of Beam Parameters: Ions (e.g. Pb)
(units)
*EBIS
Source
Linac
Booster
After
stripper
Injection
After
acceleration
208Pb30+
208Pb67+
208Pb67+
208Pb67+
~0
13.2
100
670
g
1.11
1.71
b
0.43
0.83
Charge status
Kinetic energy
MeV/u
Pulse current
mA
1.3
0.1
Pulse length
ms
0.01
0.01
Charge per pulse
μC
0.075
0.015
Ions per pulse
1010
1.0
0.2
Pulses
28
* EBIS - Electron Beam Ion Source
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
5
Ion Source Options
Ions
Source
Type
Pulse Width
Rep. Rate
Pulsed Current
Ions/pulse
μs
Hz
mA
1010
Polarization
Emittance
(90%)
π·μm·rad
H-/D-
ABPIS
500
5
4 (10)
1000
> 90%
1.0 / 1.8
H-/D-
ABPIS
500
5
150 / 60
40000/15000
0
1.8
3He++
ABPIS
500
5
1
200
70%
1
3He++
EBIS
10 - 40
5
1
5 (10)
70%
1
6Li+++
ABPIS
500
5
0.1
20
70%
1
Pb30+
EBIS
10
5
1.3 (1.6)
0.3 (0.5)
0
1
Au32+
EBIS
10 - 40
5
1.4 (1.7)
0.27 (0.34)
0
1
Pb30+
ECR
500
5
0.5
0.5 (1)
0
1
Au32+
ECR
500
5
10.5
0.4 (0.6)
0
1
ABPIS - Atomic Beam Polarized Ion Source
EBIS - Electron Beam Ion Source
ECR - Electron Cyclotron Resonance
V. Dudnikov
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
6
MEIC Collaboration Mtg, JLab, March 30, 2015
6
Warm/Cold Ion Linac - Current Baseline
EBIS
Ion Sources
RFQ
IH
ABPIS
MEBT
QWR
QWR
HWR
4 cryostats
4 cryos
2
2 cryos
1010
cryostats
cryos
Optimum stripping energy: 13 MeV/u
P. Ostroumov, ANL
Linac design based on the ANL linac for FRIB
Pulsed linac capable of accelerating multiple
charge ion species (H- to Pb67+)
Warm Linac Sections (115 MHz):
RFQ (3 m)
MEBT (3 m)
IH structure (9 m)
Cold Linac Sections:
Ion species: p to Pb
Ion species for the reference design
208Pb
Kinetic energy (p, Pb)
285 MeV
100 MeV/u
Maximum pulse current: Light ions (A/Q<3)
Heavy ions (A/Q>3)
2 mA
0.5 mA
Pulse repetition rate
up to 10 Hz
Pulse length: Light ions (A/Q<3)
Heavy ions (A/Q>3)
0.50 ms
0.25 ms
QWR + QWR (24 m + 12 m)
115 MHz
Maximum beam pulsed power
680 kW
stripper, chicane (10 m)
115 MHz
Fundamental frequency
115 MHz
HWR section (60 m)
230 MHz
Total length
121 m
Thomas Jefferson National Accelerator Facility
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Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
7
Warm RF Components
RFQ Segment
IH Structure
Frequency
115 MHz
Total length
3.6 m
Voltage
85 kV
Average radius
7 mm
Number of segments
4
Input energy
25 KeV
Output energy
500 keV/u
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
8
Superconducting Cavities
P. Ostroumov, ANL
QWR
HWR
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
9
Superconducting Ion Linac
Superconducting linac provides superior flexibility to maximize
energies for multiple charge ion beams (from H- to 208Pb67+).
SC linac can provide 100 MeV/u for lead ions.
In the same SC linac, an H- beam can reach 280 MeV, which is high
enough to suppress space-charge in the booster (space-charge is most
severe for the lowest mass-to-charge ratio, i.e. H-)
Single 2-gap SC cavity can provide significantly higher (factor of ~ 10)
voltage per cavity compared to room temperature cavities. High-Q
(power ~ voltage2) ⇨ much higher peak fields available with SC cavities.
r0lC Z 2
r0Q Z
Dn sc =
=
,
2
2
4pbg en A 4pbg en A
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
Q = lCZ
P. Ostroumov, ANL
MEIC Collaboration Mtg, JLab, March 30, 2015
10
Voltage Gain per SC Cavity – Final Energies
4
4
3.5
3
3
Voltage (MV)
Voltage (MV)
H-
3.5
208Pb67+
2.5
2
1.5
2.5
2
1.5
1
1
0.5
0.5
0
0
0.1
0.2
0.3
0.4
0.5
0.1
0.2
0.3
0.5
0.6
b
b
Proton
Dueteron
40
Ar
132
Xe
208
Pb
0.4
Q ion source Energy at the stripper
MeV/u
1
55
1
32.8
12
22.4
26
16.5
30
13.2
Q after the stripper
1
1
18
48
67
Total energy
MeV/u
285
169
150
120
102
P. Ostroumov, ANL
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
11
Ion Source/Linac – Space-Charge Issues
The space-charge effects are quite significant in the injection
beam-lines from the ion sources.
Emittance after both ABPIS and EBIS are not simple ellipses, beam
collimation is required before transferring ions into the linac.
Following the RFQ there are no significant space-charge effects
If EBIS is used for ion beam generation (peak current ~5 mA) one
needs to compensate space charge defocussing with standard rms
beam envelope matching technique.
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
12
Booster (8 GeV, gt = 10)
Ring circumference: 273 m
(≈ 2200/8)
Ekin = 285 MeV – 7.062 GeV
Injection: multi-turn 6D painting
0.22-0.25 ms long pulses ~180 turns
gt 
M56 =
S
M56
ò
D
r
Proton single pulse charge stripping
at 285 MeV
Crossing angle:
75 deg.
Ion 28-pulse drag-and-cool stacking
at ~100 MeV/u
ds
extraction
injection
70
7
RF cavity
Ion energies scaled by mas-to-charge
ratio to preserve magnetic rigidity
A. Bogacz
0
-7
DISP_X&Y[m]
BETA_X&Y[m]
M56  273 cm
0
BETA_X
BETA_Y
DISP_X
Inj. Arc (2550)
DISP_Y
272.306
Straight
Arc (2550)
Straight (RF + extraction)
Thomas Jefferson National Accelerator Facility
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Alex Bogacz 13
MEIC Collaboration Mtg, JLab, March 30, 2015
13
70
7
Booster Lattice (8 GeV, gt = 10)
0
-7
DISP_X&Y[m]
BETA_X&Y[m]
A. Bogacz
0
BETA_X
BETA_Y
DISP_X
DISP_Y
272.306
Proton beam energy (total)
GeV
1.2 - 8
Circumference
m
272.5
Arc Bends:
Arc length
m
86.9 / 77.9
Lb = 120 cm
B = 2.73 Tesla
bend ang. = 7.08 deg.
Sagitta =1.8 cm
Straight section length
m
53.8
Maximum hor. / ver. b functions
m
60 / 38
Maximum hor. dispersion
m
5.9
Arc Quadrupoles:
Straight Quads:
Lq = 40 cm
GF = 12.57 Tesla/m
GD = -24.52 Tesla/m
GF = 12.57 Tesla/m
Lq = 40 cm
G = 12-58 Tesla/m
Hor. / ver. betatron tunes nx,y
9.87 / 8.85
Hor. / ver. natural chromaticities xx,y
-28 / -24
Momentum compaction factor a
Hor. / ver. normalized emittance ex,y
Lattice configured with super-ferric magnets
Beam current
10-2
µm rad
2.7 / 2.7
Amp
0.2
Laslett tune shift at injection (protons)
0.1
Thomas Jefferson National Accelerator Facility
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Alex Bogacz 14
MEIC Collaboration Mtg, JLab, March 30, 2015
14
5
30
Ion Injection – Transverse Phase-space Painting
DISP_X&Y[m]
BETA_X&Y[m]
Doublet straight injection optics
separation of the injection orbit bump (12s)
Dx Dp
>> e x
b p
x
e x » 10-3 m1/2 ,
Dx
bx
=
4m
4m
= 2m1/2
0
-5
Dp
» 6 ´10-3 m
p
31.8
BETA_X
BETA_Y
DISP_X
DISP_Y
55
B. Erdelyi, NIU
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
15
Acceleration - Low Frequency RF Cavities
H+
Booster
Circumference 273
m
Energy
Harmonic Number 1
RF Frequency Range
Gaps per Cavity 2
Ramping Time
Cavity Number 1
208Pb67+
0.28 - 8
0.112 - 3.2
0.817 - 1.274 0.578 - 1.25
GeV
MHz
0.396
0.56
sec
Vgap
8.0
5.75
kV
8.0
1.85
kW
41.2
kW
Cavity Length 2.2
m
Beam Power
Total Cavity Length 2.2
m
Power Loss per Cavity
41.2
Ferrite Toroid Inner Radius 0.25
m
Syn. Phase
30.0
Ferrite Toroid Outer Radius 0.5
m
Acceleration time
120
144
msec
16
55
msec
Ferrite Stack Length 1
Maximum Vgap 10
m
kV
Cooling time
S. Wang
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 16
MEIC Collaboration Mtg, JLab, March 30, 2015
16
Booster - Space-Charge Issues
Incoherent space-charge tune shift at injection (285 MeV):
Present baseline: DQsc = 0.1 (for 0.2 Amp coasting beam)
Consider more aggressive scenario … DQsc ≥ 0.3
Structure resonance crossing and stop-band corrections
Significant fraction of particles in the beam can move cross thirdinteger and quarter-integer resonance lines.
I. Hofmann
GSI
G. Franchetti
FAIR
Properly placed quadrupoles and sextupoles could be used to
correct the stop-band width of those resonances to minimize the
amplitude growth and hence the beam loss.
Halo generation ⇨ beam collimation required
Thomas Jefferson National Accelerator Facility
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Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
17
Large Space-Charge Tune Shift Operation
PS Booster at CERN
tune scan
S. Gilardoni
CERN
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
18
Tune Diagram – Space-charge Footprint?
9
Table 1 Dipole, multipoles in units of 10-4, reference radius at 1.5 cm
Qx/y = 9.87 / 8.85
Qy
8.5
P. McIntyre
Texas A&M
10
Qx
b2
b4
b6
b8
bmod
-0.32176
0.08708
0.59582
-0.20929
-0.05253
0.44683
0.2
-0.6435
0.0803
0.59617
-0.20927
-0.05253
0.89361
0.3
-0.96518
0.07208
0.59682
-0.20924
-0.05253
1.34025
0.4
-1.28668
0.0619
0.59569
-0.20889
-0.05255
1.78582
0.5
-1.6071
0.0238
0.58361
-0.20639
-0.05266
2.22453
0.6
-1.91987
-0.28566
0.57678
-0.19833
-0.0531
2.63669
0.7
-2.21129
-0.93483
0.62211
-0.18461
-0.05412
3.0095
0.8
-2.48116
-1.31638
0.75232
-0.17323
-0.0554
3.35539
0.9
-2.72932
-0.94327
1.00524
-0.17088
-0.05669
3.6795
1
-2.95464
0.21439
1.27708
-0.17257
-0.05813
3.98352
1.1
-3.16415
1.7906
1.52332
-0.17535
-0.05968
4.27484
Nominal current 15kA (Iscale=1)
Table 2 Quad multipoles, reference radius 3 cm
-7
DISP_X&Y[m]
BETA_X&Y[m]
Tracking for 1.2×105 turns
0
0
b0 (T)
0.1
7
2 3 4 5
70
9.5
Iscale
BETA_X BETA_Y DISP_X
DISP_Y
272.306
Iscale
b1 (T/m)
b5
b9
Bmod
0.05
-10.21812
-0.78158
-0.1525
0.53951
0.1
-18.11761
-0.81085
-0.15758
0.96571
0.2
-25.81432
-1.06328
-0.18984
1.5147
0.3
-32.11643
-1.75817
-0.25051
2.08225
0.4
-37.24015
-3.20299
-0.31863
2.59426
0.5
-41.67083
-6.61844
-0.28676
3.07151
0.6
-45.60973
-9.07414
0.24837
3.53291
0.7
-49.17036
-5.91589
0.67629
3.99022
0.8
-52.54698
-0.26071
0.60584
4.4499
0.9
-55.8136
4.91642
0.43936
4.90185
1
-58.99089
9.33004
0.27043
5.34909
1.1
-62.07561
13.03944
0.11773
5.78807
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
19
Linac-to-Booster Transfer Line
Booster injection scheme
̶
Combined longitudinal and transverse phase space painting
̶
Components: stripping foil, four-dipole booster orbit bumper system, magnetic and electrostatic septa
Two same-strength quadrupole families of opposite sign
̶
Eighteen 16 T/m 20/30 cm magnetic/physical length quadrupoles
̶
Each quadrupole surrounded by 30 cm long corrector and 15 cm long BPM
̶
Enough quadrupoles for matching to linac and booster as needed
Achromatic 1 m vertical step
̶
Two 0.5 T 50/78 cm magnetic/physical length dipoles
matching
vertical step
matching
ions
V. Morozov
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
20
Booster-to-Ion Ring Transfer Line
DISP_X&Y[m]
BETA_X&Y[m]
50
6
Lattice based on FODO (900 )
0
-6
Enough independent quadrupoles (8) for
betatron matching to Ion Ring
0
kicker
BETA_X
BETA_Y
DISP_X
DISP_Y
83.8917
127.50 Arc
septum
septum
Booster
Extraction
-2 Coordinates X&Y[cm]
2
Kickers (2):
L[cm]
B[kG]
angle [mrad]
0
Y
Ion Ring
Injection
120
1.5
5
Rise time [ns] Flat Top [ns] Fall time [ns]
300
300
300
Horizontal Extraction: Kicker + Septum
X
kicker
A. Bogacz
5.5
Thomas Jefferson National Accelerator Facility
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Alex Bogacz 21
MEIC Collaboration Mtg, JLab, March 30, 2015
21
Summary
The MEIC hadron injector complex design is well established
Present choice for Ion Sources:
ABPIS for polarized protons and light ions
EBIS for un-polarized heavy ions
SRF Linac based on FRIB (285 MeV protons and 100MeV/u lead)
8 GeV Booster design avoiding transition crossing (including transfer lines)
Low momentum compaction Optics based on perturbed FODO lattice
Lattice configured with super-ferric magnets (Texas A&M design)
Injection: Combined longitudinal and transverse phase-space painting
Extraction: Single kicker and magnetic septum
Space-charge tune ‘footprint’ needs to be studied in the presence of multipoles
No clearly identified technical risks present
Proven, conservative technologies used throughout the scheme
Thomas Jefferson National Accelerator Facility
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Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
22
Backup Slides
Thomas Jefferson National Accelerator Facility
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Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
23
Medium Energy Beam Transport (MEBT)
x
x
x’
Q2 Q3 Q4
Q1
y
Buncher
x’
y
y’
y’
L= 995 mm
Df
DW/W
Df
Space-charge defocusing significant rms beam envelope matching required
Quadrupole Parameters
DW/W
Buncher Parameters
Eff. Length
(mm)
Gradient
(T/m)
Cavity
Quarter Wave
Q1
20.0
23.0
Voltage
0.8 MV
Q2
50.0
-22.0
Frequency
115 MHz
Q3
50.0
32.75
Length
340 mm
Q4
50.0
-16.5
Thomas Jefferson National Accelerator Facility
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Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
24
Stripping energy
208Pb30+

208Pb67+
440
Linac total voltage (MV)
430
420
410
400
390
380
0
5
10
15
20
25
30
Stripping energy (MeV/u)
P. Ostroumov, ANL
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
25
0
0
0
DISP_X&Y[m]
BETA_X&Y[m]
30
3
Arc Cell - Super-ferric Magnets
BETA_X
Bend
BETA_Y
Sextupole
DISP_X
DISP_Y
8.76306
Bend:
Bend
Correctors BPM
Lb = 120 cm (magnetic
length)
P. McIntyre
Texas A&M
Lead ends: 2×22 cm
Dual-dipole
Quad
B = 2.73 Tesla
bend ang. = 7.08 deg.
Sagitta =1.8 cm
Half-cell cryomodule
Magnet aperture radius:
6srms = 42 mm
Sextupole:
Quad
Quadrupole:
Lq = 40 cm
G = 12-58 Tesla/m
Correctors (H/V): 10 cm
BPM can: 10 cm
Ls = 10 cm
S = 750 Tesla/m2
Thomas Jefferson National Accelerator Facility
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Alex Bogacz 26
MEIC Collaboration Mtg, JLab, March 30, 2015
26
Adiabatic Capture and Acceleration (h =1)
Energy
RF Frequency Range
Ramping Time
H+
0.28 - 8
0.817 - 1.274
0.396
208Pb67+
0.112 - 3.2
0.578 - 1.25
0.56
GeV
MHz
sec
protons
lead ions
B. Erdelyi, NIU
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
27
Booster-to-Ion Ring Transfer Line - Magnets
0
-6
DISP_X&Y[m]
BETA_X&Y[m]
50
6
Lattice based on FODO (900 )
0
kicker
BETA_X
BETA_Y
DISP_X
septum
DISP_Y
83.8917
127.50 Arc
septum
Ion Ring
Injection
Arc Bends (28):
Booster
Extraction
kicker
Lb = 120 cm
Magnetic Septa (2):
B = 1.89 Tesla
Lb = 150 cm
bend ang. = 4.9 deg.
B = 1.5 Tesla
sagitta = 1.3 cm
bend ang. = -4.9 deg.
Arc Quadrs (17):
Lq = 40 cm
G = 10-25 Tesla/m
Magnet aperture radius:
A. Bogacz
6srms = 16 mm
Thomas Jefferson National Accelerator Facility
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Alex Bogacz 28
MEIC Collaboration Mtg, JLab, March 30, 2015
28
Other Boosters - Tunes
SNS Accumulator:
5.82 / 5.80
SSC LEB:
11.65 / 11.60
SPS:
1.82 / 2.72
SPS Booster:
6.23 / 6.25
J-PARC RCS:
6.45 / 6.42
MEIC Booster:
9.87 / 8.85
Thomas Jefferson National Accelerator Facility
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Alex Bogacz
MEIC Collaboration Mtg, JLab, March 30, 2015
29