Page 1 Review 09/2010 MEIC Ion Linac and Pre-Booster Design Bela Erdelyi Department of Physics,...
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Page 1 Review 09/2010 MEIC Ion Linac and Pre-Booster Design Bela Erdelyi Department of Physics, Northern Illinois University, and Physics Division, Argonne National Laboratory
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Transcript of Page 1 Review 09/2010 MEIC Ion Linac and Pre-Booster Design Bela Erdelyi Department of Physics,...
Page 1Review 09/2010
MEIC Ion Linac and Pre-Booster DesignMEIC Ion Linac and Pre-Booster Design
Bela Erdelyi Department of Physics, Northern Illinois University,and Physics Division, Argonne National Laboratory
Page 2Review 09/2010
Acknowledgements
• Joint Work of• Bela Erdelyi (NIU/ANL)• Shashikant Manikonda (ANL)• Peter Ostroumov (ANL)• Sumana Abeyratne (NIU student)• With assistance from JLab staff (Y. Derbenev, Y. Zhang, G.
Krafft, etc.)
• Joint Work of• Bela Erdelyi (NIU/ANL)• Shashikant Manikonda (ANL)• Peter Ostroumov (ANL)• Sumana Abeyratne (NIU student)• With assistance from JLab staff (Y. Derbenev, Y. Zhang, G.
Krafft, etc.)
Page 3Review 09/2010
ELIC Conceptual Layout
Three compact rings:• 3 to 11 GeV electron• Up to 12 GeV/c proton (warm)• Up to 60 GeV/c proton (cold)
Page 4Review 09/2010
Ion Linac for ELIC
• Pulsed linac• Short Normal Conducting section: RFQ and IH
structure• Followed by Superconducting section that contains
• Stripper for heavy ions at 12 MeV/u
Page 5Review 09/2010
Basic Parameters of the Linac
• Linac layout
Parameter Value
1 Ion species From Hydrogen to Lead 2 Ion species for the reference design 208Pb 3 Kinetic energy of lead ions 100 MeV/u 4 Maximum beam current averaged over the pulse 2 mA 5 Pulse repetition rate 10 Hz 6 Pulse length 0.25 msec 7 Maximum beam pulsed power 680 kW 8 Fundamental frequency 115 MHz 9 Total length 150 m
IS MEBT Stripper
RFQ IH QWR QWR HWR DSR
Normal conducting Superconducting
80
Page 6Review 09/2010
Superconducting Cavities
• Developed for the RIA/FRIB project
QWR HWR DSR
Page 7Review 09/2010
Voltage Gain per Cavity forProtons and Lead Ions
0
0.5
1
1.5
2
2.5
3
3.5
4
0.1 0.2 0.3 0.4 0.5b
Vol
tage
(M
V)
0
0.5
1
1.5
2
2.5
3
3.5
4
0.1 0.2 0.3 0.4 0.5 0.6b
Vol
tage
(M
V)
Page 8Review 09/2010
QWR and HWR production at ANL
• QWR, f=109 MHz, b=0.15• HWR, f=172 MHz, b=0.26
Page 9Review 09/2010
Cryomodule assembly at ANL
beam
Page 10Review 09/2010
Accumulator/Pre-Booster Concept
• Purpose:• Inject from linac• Accumulate ions• Accelerate them• Extract and send to large booster
• Concepts:• Figure-8 shape for ease of spin transport, manipulation and
preservation• Modular design, with (quasi)independent module design
optimization• FODO arcs for simplicity and ease of implementation of optics
correction schemes• No dispersion suppressors• Injection insertion• Doublet/Triplet straights for long dispersion-less drifts• Matching/tuning modules in between
Page 11Review 09/2010
Constraints
• Figure-8 shaped; circumference ~250 m• Maximum bending field: 1.5 T• Maximum quadrupole gradient: 20 T/m• Momentum compaction smaller than 1/25• Maximum beta functions less than 35 m• Maximum full beam size less than 2.5 cm and 1 cm vertically in dipoles• 5m m long dispersion-less sections for RF cavities, electron cooling
collimation and extraction• Sizable (normalized) dispersion for/at injection• Working point chosen such that tune footprint does not cross low
order resonances (tunability)
Page 12Review 09/2010
Injection
• Protons (and light ions)• Stripping injection
• Heavy ions• Repeated multi-turn injection• Transverse (horizontal and possibly also vertical)
and longitudinal painting• Electron cooling for stacking/accumulation
Page 13Review 09/2010
Heavy-Ion Injection
Page 14Review 09/2010
Acceleration
• h=1• RF swing necessary is [0.4,2] MHz
• 15 kV per cavity• 50kV/turn => 3-4 cavities• 56000 turns for 200MeV -> 3 GeV• Less than 80 ms acceleration time
Page 15Review 09/2010
Extraction
• Conventional fast extraction
Page 16Review 09/2010
Layout
ARC 1
Injection Insertion section
ARC 2
Non dispersive section 1
ARC 3
Non dispersive section 2
RF cavity
Electron Cooling
Solenoid for Electron Cooling
ExtractionCollimation
Beam from
LINAC
Page 17Review 09/2010
Linear Optics
Inje
ctio
n
Arc
1
Str
aig
ht
1 Arc
3
Str
aig
ht
2 Arc
2
Page 18Review 09/2010
Optical modules
ARC1&2 FODO ARC3 FODO
STRAIGHT TRIPLET INJECTION INSERT
Page 19Review 09/2010
Tunability
Page 20Review 09/2010
Main Parameters Units Value
1 Circumference m 302
2 Angle at crossing deg 44
3 Number of dispersive FODO cells (Type I) 6
4 Number of dispersive FODO cells (Type II) 8
5 Number of triplet cells 18
6 Number of matching cells (2 types) 4
7 Minimum drift length between magnets cm 50
8 Drift length in the injection insertion m 5.0
9 Drift lengths between triplets (for RF, extraction, collimation and electron cooling) m 5.3
10 Beta maximum in X m 33
11 Beta maximum in Y m 36
12 Maximum beam size cm 2.3
12 Maximum vertical beam size in the dipole magnets cm 0.6
13 Maximum dispersion (x|delta_KE) m 3.3
14 Normalized dispersion value at injection insert m½ 2.1
15 Tune in X 7.92
16 Tune in Y 7.24
17 Gamma of particle 4.22
18 Gamma at transition energy 5.6
19 Momentum compaction 3.2E-2
Page 21Review 09/2010
Magnets
Quantity Parameters Units Value
1 Quadrupole Magnets 113
Length cm 40
Half aperture cm 5
Maximum pole tip field T 1.5
Minimum pole tip field T 0.15
2 Dipole Magnets (Type I) 16
Strength T 1.41
Radius m 9.0
Vertical aperture cm 3.0
Angle deg 11.6
Length m 1.83
3 Dipole Magnets (Type II) 18
Strength T 1.41
Radius m 9.0
Vertical aperture cm 3.0
Angle deg 14.0
Length m 2.19
Page 22Review 09/2010
Summary and Work in Progress
• Presented a preliminary design of the linac and the accumulator/pre-booster, which satisfy the constraints while providing superior performance
• Fine tuning first order optics• Space charge limits on current and emittance• Spin and spin-orbit resonance analysis• Dynamic aperture estimation
• Presented a preliminary design of the linac and the accumulator/pre-booster, which satisfy the constraints while providing superior performance
• Fine tuning first order optics• Space charge limits on current and emittance• Spin and spin-orbit resonance analysis• Dynamic aperture estimation
Page 23Review 09/2010
BACKUP SLIDES
Page 24Review 09/2010
Cavity subsystems
• 4 kW capacitive coupler• Adjustable• 1 cold/warm
windows • Pneumatic slow tuner
• Piezoelectric tuner (PZT)• ~90 Hz window• 35 m
displacement
Ceramic disk LN out
LN in
beam
PZT has been tested withexcellent performance
Page 25Review 09/2010
Proton beam
• Setting 1:
• Mass= 1, Charge= 1, Kinetic Energy = 3000 MeV
• Electric rigidity (χe) = 3.71E+9 V
• Magnetic Rigidity (χm) = 12.74 Tm
• Proton beam Emittance in x and y = 16 π mm·mrad
• x=± 4mm y=± 4mm ,
• a=±4mrad b = ±4mrad
• Kinetic Energy Dispersion (δKE/KE )= 1E-4 • Setting 2:
• Mass= 1, Charge= 1, Kinetic Energy = 200 MeV
• Electric rigidity (χe) = 3.68E+8 V
• Magnetic Rigidity (χm) = 2.14 Tm
• Proton beam Emittance in x and y = 140π mm·mrad
• x=± 4mm y=± 4mm ,
• a=±35mrad b = ±35mrad
• Kinetic Energy Dispersion (δKE/KE )= 1E-2
2529-31 July,2010
Page 26Review 09/2010
Main Parameters (1)
• Energy range• Protons: from 200 MeV (β=0.57, γ=1.21) @ injection
to 3 GeV (β=0.97, γ=4.2) at extraction• Lead ions: if fully stripped, from 80 MeV/u (β=0.39,
γ=1.08) @ injection to 1.18 GeV/u (β=0.9, γ=2.26) @ extraction
• Circumference• An integer multiple of it must be ~900-1000 m =>
~250-300 m
Page 27Review 09/2010
Main parameters (2)
• Revolution times/frequencies• Protons @ injection:
• {0.883753 μs,1.13154 MHz} if C=150m• {0.515181 μs,1.94107 MHz} if C=300m
• Protons @ extraction:• {1.76751 μs,0.565769 MHz} if C=150m• {1.03036 μs,0.970533 MHz} if C=300m
• Pb @ injection:• {1.29609 μs,0.771552 MHz} if C=150m• {0.557907 μs,1.79241 MHz} if C=300m
• Pb @ extraction:• {2.59218 μs,0.385776 MHz} if C=150m• {1.11581 μs,0.896207 MHz} if C=300m
• If acceleration done with h=1• RF swing necessary is [0.38,1.95] MHz
Page 28Review 09/2010
Cooling times
• Assuming:• 3 m long cooling section• 300 mA electron current• 2.5 cm beam radius• ± 5 mrad beam divergence• ±0.004 momentum dispersion• Cooling for 3 time constants
Transverse cooling time: ~ 130 ms Longitudinal cooling time: ~ 67 ms
Cooling electron energies:• @ injection: { 0.55394 MeV, γ=2.0840 }• @ extraction: { 1.15511 MeV, γ=3.2605 }
Page 29Review 09/2010
Lead Charge Distributions
• @ injection• Q (0) Q (1) Q (2) Q (3) Q (4)• 0 4% 70% 22% 3%
• @ extraction• Q (0) Q (1)• 83% 17%
Page 30Review 09/2010
Intensities
• Protons• If assuming 1A current, depending on circumference and
injection/extraction:=> N_p ~ [ 3 , 11 ] x 1012
• Lead ions• Under similar circumstances:
=> N_Pb ~ N_p / Q
Page 31Review 09/2010
Pre-Booster Cycle Time
• Assuming 5x1010 lead ions need to be accumulated• One linac pulse delivers ~2x108 ions (assumed @
~50% efficiency)• 50 linac pulses, 250 μs each• Total time = 50x 250 μs +50x130 ms+2x80 ms ≈ 7 s
Page 32Review 09/2010 29-31 July,2010
Shorter Version Layout
Page 33Review 09/2010 29-31 July,2010
Shorter Version Lattice functions
Page 34Review 09/2010 29-31 July,2010
Units Value
1 Total length m 254
2 Angle at crossing deg 60
3 Number of dispersive FODO cells (Type I) 6
4 Number of dispersive FODO cells (Type II) 8
5 Number of triplet cells 12
6 Number of matching cells 4
7 Minimum drift length between magnets cm 50
8 Drift lengths in the insertion region m 5.0
9 Drift lengths between triplets (for RF, collimation and electron cooling) m 5.0
10 Beta maximum in X m 32
11 Beta maximum in Y m 32
12 Maximum beam size cm 2.5
12 Maximum beam size in the dipole magnets cm 0.6
13 Maximum Dispersion (x|delta_KE) 2.5
14 Normalized dispersion value at injection (x|δ_KE)/√β 1.41
15 Tune in X 7.24
16 Tune in Y 6.60
17 Gamma of particle 4.22
18 Gamma at Transition Energy 4.7
19 Momentum compaction factor 4.4E-2
Shorter Version Parameters
Page 35Review 09/2010
Quantity Parameters Units Value
1 Quadrupole Magnet 95
Length cm 40
Half aperture cm 5
Maximum pole tip field
T 1.5
Minimum pole tip field
T 0.16
2 Dipole Magnet (Type I) 12
Strength T 1.41
Radius m 9
Vertical aperture cm 3
Angle deg 14
Length m 2.19
3 Dipole Magnet (Type II) 18
Strength T 1.41
Radius m 9
Vertical aperture cm 3
Angle deg 12.9
Length m 2.04
4 Dipole Magnet (Type III) 18
Strength T 1.41
Radius m 9
Vertical aperture cm 3
Angle deg 14.9
Length m 2.35
Shorter Version Magnets
Page 36Review 09/2010
New Layout with 5 quads in each matching section (302m)
