Ion Booster Ring
Alex Bogacz
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
JLEIC
Alex
Collaboration
Bogacz
Meeting, Fall 2016
1
8 GeV Booster - Overview
Ekin = 285 MeV – 7.062 GeV
Ring circumference: 275 m
(2200/8)
RF cavity
kicker
Crossing angle: 79.8 deg.
extraction
injection
Injection: multi-turn 6D painting
Booster functionality:
Accumulation of injected ions
0.22 – 0.25 ms long pulses ~180 turns
Cooling of ions (DC electron cooling)
Proton single pulse charge stripping at 285 MeV
Acceleration of ions
Ion 28-pulse drag-and-cool stacking at 100MeV/u
Extraction/Transfer of ions
to the collider ring
Ion energies scaled by mass-to-charge ratio
to preserve magnetic rigidity
Preserving ion polarization - Figure-8 shape
Extraction: kicker-septum
Bunch splitting?
300 ns (rise) – 300 ns (flat top) – 300 ns (fall)
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
2
JLEIC Collaboration Meeting, Oct. 5, 2016
2
Booster (8 GeV, t = 16.8 i ) - Optics
Ekin = 285 MeV – 7.062 GeV
Ring circumference: 275 m
(2200/8)
RF cavity
kicker
M56 
Crossing angle: 79.8 deg.
t 
extraction

S
M56
D

ds  0
(imaginary )
5
40
injection
M56  -98 cm
DISP_X&Y[m]
0
-5
BETA_X&Y[m]
S  275 m
0
BETA_X
BETA_Y
DISP_X
Inj. Arc (259.80)
Operated by JSA for the U.S. Department of Energy
DISP_Y
275.087
Straight
Arc (259.80)
Thomas Jefferson National Accelerator Facility
Alex Bogacz
3
Straight
JLEIC Collaboration Meeting, Oct. 5, 2016
3
‘Arc Cell’ - Lightly Perturbed FODO
DISP_X&Y[m]
BETA_X&Y[m]
40
5
900 FODO – Empty - 900 FODO
0
-5
M56 – always positive
BETA_Y
D
ds
r
DISP_X
DISP_Y
DGF
26.2911
DGF
5
ò
BETA_X
BETA_X&Y[m]
40
M56 =
0
0
-5
DISP_X&Y[m]
M56 – small negative
0
BETA_X
BETA_Y
DISP_X
DISP_Y
DGF
26.2911
DGF
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
4
‘Arc Cell’ - Lightly Perturbed FODO
DISP_X&Y[m]
BETA_X&Y[m]
40
5
900 FODO – Empty - 900 FODO
0
-5
M56 – always positive
BETA_Y
DISP_X
DISP_Y
26.2911
D
ds
r
5
ò
BETA_X
40
M56 =
0
0
-5
DISP_X&Y[m]
BETA_X&Y[m]
M56 – negative
0
BETA_X
BETA_Y
DISP_X
DISP_Y
21.808
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
5
‘Arc Cell’ - Chromaticity Correction
xy = -0.72
0
-5
DISP_X&Y[m]
BETA_X&Y[m]
xx = -1.53
5
40
900 FODO – Empty - 900 FODO
0
BETA_X
s4
BETA_Y
s1
DISP_X
s3
DISP_Y
s1
21.808
s4
s2
si ~ 150 Tesla/m2
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
6
Arcs - Optics
5
40
Arc
DISP_X&Y[m]
0
-5
BETA_X&Y[m]
32 bends
BETA_X
BETA_Y
DISP_X
DISP_Y
85.1122
40
Arc Cell
Arc Cell
5
0
DISP_X&Y[m]
BETA_X&Y[m]
Injection Arc
0
-5
32 bends
0
BETA_X
BETA_Y
DISP_X
DISP_Y
103.264
Arc Cell
Arc Cell
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
7
DISP_X&Y[m]
DISP_X&Y[m]
Injection orbit bump separation: 10s
BETA_X&Y[m]
BETA_X&Y[m]
5
5
Doublet based injection optics
30
30
Ion Injection – Transverse Phase-space Painting
Dx Dp
 10  x
x p
0
-5
 x  10 -3 m1/ 2 ,
BETA_X
BETA_Y
DISP_X
DISP_Y
55
0
-5
31.8
39.6
BETA_X
BETA_Y
DISP_X
63.6
5 meters
Dx
x

3.4m
4m
 1.7m1/ 2
Dp
 6  10 -3
p
Two-plane painting injection:
Tilted septum
Simultaneous H/V phase-space painting
4-6 times of intensity gain compare to the
single-plane multi-turn injection (HIAF)
Two groups of orbit bumps for both the
horizontal and vertical planes
B. Erdelyi, NIU
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
8
0
-5
DISP_X&Y[m]
BETA_X&Y[m]
5
40
Booster Lattice (8 GeV, t = 16.8 i )
0
BETA_X
BETA_Y
DISP_X
DISP_Y
275.087
Proton beam energy (total)
GeV
1.2 - 8
m
275
deg
79.8
Arc length
m
103 / 85
Straight section length
m
43
Maximum hor. / ver.  functions
m
22 / 22
Maximum hor. dispersion
m
4.3
Arc Bends:
Circumference
Lb = 120 cm
B = 3.13 Tesla
bend ang. = 8.12 deg.
Sagitta = 2.1 cm
Straights’ crossing angle
Arc Quadrupoles:
Straight Quads:
Lq = 40 cm
GF = 12.6 Tesla/m
GD = -24.5 Tesla/m
Lq = 40 cm
G = 12-65 Tesla/m
Lattice configured with super-ferric magnets
Hor. / ver. betatron tunes x,y
7.87 / 5.85
Hor. / ver. natural chromaticitiesxx,y
-6.8 / -4.6
Momentum compaction factor 
-3.6 10-3
Hor. / ver. normalized emittance x,y
Maximum hor. / ver. rms beam size at inj. sx,y
µm rad
1/1
mm
5.1 / 5.1
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
9
JLEIC Collaboration Meeting, Oct. 5, 2016
9
0
-3
DISP_X&Y[m]
BETA_X&Y[m]
30
3
Arc Cell - Super-ferric Magnets
4.4
BETA_X
Bend
BETA_Y
Sextupole
DISP_X
DISP_Y
17.2
Bend
Correctors BPM
Quad
Dual-dipole + Quad Cryomodule
Quadrupole:
Lq = 40 cm
Bend:
Lb = 120 cm (magnetic length)
Lead ends: 2×22 cm
Dual-dipole
Quad
B = 3.13 Tesla
bend ang. = 8.12 deg.
P. McIntyre
Texas A&M
Magnet aperture radius (inj. at 285 MeV)
Sagitta = 2.1 cm
6srms + 10 mm = 41 mm
G = 10-37 Tesla/m
Correctors (H/V): 20 cm
BPM can: 20 cm
Sextupole:
Ls = 10 cm
S = 780 Tesla/m2
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 10
JLEIC Collaboration Meeting, Oct. 5, 2016
10
0
-3
DISP_X&Y[m]
BETA_X&Y[m]
30
3
Arc Cell - Super-ferric Magnets
4.4
BETA_X
Bend
BETA_Y
Sextupole
DISP_X
Bend
DISP_Y
17.2
Correctors BPM
Quad
T. Michalski
JLAB
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 11
JLEIC Collaboration Meeting, Oct. 5, 2016
11
1
1
Beam Envelopes (rms) at Injection
E = 285 MeV
s x ,y   x ,y
Dp/p = 5x10-4
Size_X[cm]
Size_Y[cm]
 N .rms  10-6 m rad
 N .rms

0
0
 xmax
,y  22 meters
4.4
Ax_bet
Bend
Ay_bet
Sextupole
Ax_disp
17.2
Bend
Correctors BPM
Quad
E = 285 MeV
 = 0.84
Lower inj. energy:
E = 135 MeV
 = 0.54
s xmax
,y  5.1 mm
s xmax
,y  6.4 mm
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 12
JLEIC Collaboration Meeting, Oct. 5, 2016
12
Acceleration - Low Frequency RF Cavities
H+
Booster
Circumference 273
m
Harmonic Number 1
Energy
RF Frequency Range
208Pb67+
0.28 - 8
0.112 - 3.2
0.695 - 1.084 0.578 - 1.25
GeV
MHz
Gaps per Cavity 2
Cavity Number 2
Cavity Length 2.2
m
Ferrite Toroid Inner Radius 0.25
m
Ferrite Toroid Outer Radius 0.5
m
Ferrite Stack Length 1
Maximum Vgap 10
Vgap
8.0
5.75
kV
Beam Power
8.0
1.85
kW
Power Loss per Cavity
41.2
41.2
kW
Syn. Phase
30.0
m
kV
S. Wang
JLAB
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 13
JLEIC Collaboration Meeting, Oct. 5, 2016
13
JLEIC Complex - Layout
Booster crossing angle: 79.80
Transfer Line net bend angle:
900 + ½ 79.80 = 129.90
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
14
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
129.90 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
5.5
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 15
JLEIC Collaboration Meeting, Oct. 5, 2016
15
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
129.90 Arc
septum
Booster
Extraction
kicker
Ion Ring
Injection
Arc Bends (28):
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:
6srms = 17 mm
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz 16
JLEIC Collaboration Meeting, Oct. 5, 2016
16
Extreme Space-Charge Consideration
Incoherent space-charge tune shift at the injection plateau, where the
beam is stored for a long time (105 or more turns).
Present baseline: DQsc = 0.1
DQsc= 0.1
6
Qx/y = 7.87 / 5.85
More aggressive scenario:
DQsc ≥ 0.3
Qy
Significant fraction of particles in the beam
will move across the third-integer and
quarter-integer resonance lines → increases
the transverse amplitude of particles, leading
to halo formation and eventually beam loss.
5.5
Resonance crossing and halo formation
7.5
2 3 4 5
Qx
8
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
17
Next Step: Extreme Space-Charge Optimization
Mitigation of halo formation and beam loss through comprehensive
tracking studies (e.g. SYNERGIA) of resonance crossing in the
presence of space-charge and implementation of modern resonance
compensation techniques.
Implementation of third-integer resonance crossing correction
measures by creating anti-resonances via properly placed pairs of
sextupoles . They would correct the stop-band width of these
resonances to minimize the amplitude growth and hence beam loss.
Establish the optimum injection energy, working point tunes,
maximum current through assessment of the acceptable halo and
beam loss.
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
March 23, 2016
18
Summary
8 GeV Booster design based on imaginary t lattice
Negative momentum compaction lattice based on lightly perturbed 900 FODO
Injection: Combined longitudinal and transverse phase-space painting
Lattice configured with super-ferric 3 Tesla magnets (Texas A&M design)
32 × 3.1 Tesla dual-dipoles
moderate magnet aperture radius (4.1 cm)
Low betas (20 m vs 15 m FODO), good tunability, low sensitivity to errors
Flexible control of chromaticity with 2 families of sextupoles in each plane
Booster-to-Ion Ring Transfer Line
Extraction: Single kicker and magnetic septum: Rise/Flat/Fall time (~300 nsec)
Next Step... Comprehensive tracking studies of resonance crossing in the
presence of space-charge → resonance compensation
Implementation of modern halo mitigation techniques, e.g. anti-resonances
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
19
Backup Slides
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
20
x, x. x
x, x. x
Space-charge induced Twiss parameter mismatch of the injected
beam causes beam loss during the phase-space painting.
Thomas Jefferson National Accelerator Facility
W. Chai , HIAF
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
Space-Charge
JLEIC Collaboration
2015, Oxford,Meeting,
UK, March
Oct.
25,
5, 2015
2016
21
Adiabatic Capture and Acceleration (h =1)
Energy
RF Frequency Range
H+
0.28 - 8
0.695 - 1.084
208Pb67+
0.112 - 3.2
0.578 - 1.25
GeV
MHz
protons
lead ions
B. Erdelyi, NIU
Thomas Jefferson National Accelerator Facility
Operated by JSA for the U.S. Department of Energy
Alex Bogacz
JLEIC Collaboration Meeting, Oct. 5, 2016
22