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IN JECT ION BEAM LINE OPT IMIZAT ION
February 18, 2019 Benat Alberdi (on behalf of JEDI collaboration) IKP-2, FZ-Juelich
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Summary
Brief introduction to accelerator physics.COSY facility overview
Beam sourceJULIC CyclotronInjection Beam LineInjection
OptimizationIBL optimizationTrackingEmittance measurement
Next steps
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Introduction
[xx′
]s1= M(s1, s0) ·
[xx′
]s0
M = MD ·MQD ·MD ·MQF
Rms beam size:σrms =
√εβ
Geometrical emittance:ε = πε
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Introduction
[xx′
]s1= M(s1, s0) ·
[xx′
]s0
M = MD ·MQD ·MD ·MQF
Rms beam size:σrms =
√εβ
Geometrical emittance:ε = πε
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Introduction
[xx′
]s1= M(s1, s0) ·
[xx′
]s0
M = MD ·MQD ·MD ·MQF
Rms beam size:σrms =
√εβ
Geometrical emittance:ε = πε
2 / 32
Introduction
[xx′
]s1= M(s1, s0) ·
[xx′
]s0
M = MD ·MQD ·MD ·MQF
Rms beam size:σrms =
√εβ
Geometrical emittance:ε = πε
2 / 32
Introduction
[xx′
]s1= M(s1, s0) ·
[xx′
]s0
M = MD ·MQD ·MD ·MQF
Rms beam size:σrms =
√εβ
Geometrical emittance:ε = πε
2 / 32
Introduction
[xx′
]s1= M(s1, s0) ·
[xx′
]s0
M = MD ·MQD ·MD ·MQF
Rms beam size:σrms =
√εβ
Geometrical emittance:ε = πε
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Facility overview
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Facility overview
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Facility overview
p = 0.3 − 3.7 GeV/cL = 184 m
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Facility overview
p = 0.3 − 3.7 GeV/cL = 184 m
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Beam source
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Beam source
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Beam source
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Beam source
2.0-4.5 KeV/Abeams.20ms pulses.Polarization upto 80%.
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JULIC Cyclotron
Commissioned in 1968. Upgraded in 1992.
Originally built for light ionsup to Ar.Nowadays only used for H−and D−.
700 tons of iron.f = 20− 30MHz.< B >max= 1.35T
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JULIC Cyclotron
Commissioned in 1968. Upgraded in 1992.
Originally built for light ionsup to Ar.Nowadays only used for H−and D−.
700 tons of iron.f = 20− 30MHz.< B >max= 1.35T
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JULIC Cyclotron
Commissioned in 1968. Upgraded in 1992.
Originally built for light ionsup to Ar.Nowadays only used for H−and D−.
700 tons of iron.f = 20− 30MHz.< B >max= 1.35T
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JULIC Cyclotron
Imax = 0.1mA at extraction.
Provides 45 MeV H− or 76 MeVD− beams with 20 ms cycles.
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JULIC Cyclotron
Imax = 0.1mA at extraction.
Provides 45 MeV H− or 76 MeVD− beams with 20 ms cycles.
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JULIC Cyclotron
Imax = 0.1mA at extraction.
Provides 45 MeV H− or 76 MeVD− beams with 20 ms cycles.
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JULIC Cyclotron
Imax = 0.1mA at extraction.
Provides 45 MeV H− or 76 MeVD− beams with 20 ms cycles.
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Injection Beam Line (IBL)
Provides the connection betweenJULIC cyclotron and COSY.
It is 94m long.30mm of vertical offset.Composed by 42 quadrupolemagnets, 12 dipole magnetsand 14 steerer magnets.Diagnostic tools included alongthe IBL: 8 profile grids and 3phase probes.Injection dipole at the end.
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Injection Beam Line (IBL)
Provides the connection betweenJULIC cyclotron and COSY.
It is 94m long.30mm of vertical offset.Composed by 42 quadrupolemagnets, 12 dipole magnetsand 14 steerer magnets.Diagnostic tools included alongthe IBL: 8 profile grids and 3phase probes.Injection dipole at the end.
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Injection Beam Line (IBL)
Provides the connection betweenJULIC cyclotron and COSY.
It is 94m long.30mm of vertical offset.Composed by 42 quadrupolemagnets, 12 dipole magnetsand 14 steerer magnets.Diagnostic tools included alongthe IBL: 8 profile grids and 3phase probes.Injection dipole at the end.
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Injection Dipole
Injection in COSY is performed by stripping injection into a "distortedorbit".Injection dipole is responsible to align the beam coming from thecyclotron with the beam cycling in COSY.
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Injection Dipole
Injection in COSY is performed by stripping injection into a "distortedorbit".Injection dipole is responsible to align the beam coming from thecyclotron with the beam cycling in COSY.
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Injection Dipole
Injection in COSY is performed by stripping injection into a "distortedorbit".Injection dipole is responsible to align the beam coming from thecyclotron with the beam cycling in COSY.
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InjectionDistorted orbit
Displacement x can be controlled by the steerer magnets, but not the anglex’.
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InjectionDistorted orbit
Displacement x can be controlled by the steerer magnets, but not the anglex’.
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Optimization
OverviewThe goal is to make the injection ofparticles into COSY as efficient aspossible. Steps:
Develop a model for the IBL.Match design specifications.Control injection point params.Match IBL emittance with COSYacceptance.
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Optimization
OverviewThe goal is to make the injection ofparticles into COSY as efficient aspossible. Steps:
Develop a model for the IBL.Match design specifications.Control injection point params.Match IBL emittance with COSYacceptance.
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Optimization
OverviewThe goal is to make the injection ofparticles into COSY as efficient aspossible. Steps:
Develop a model for the IBL.Match design specifications.Control injection point params.Match IBL emittance with COSYacceptance.
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Injection optimizationIBL
Not all quadrupoles independent→ 12free parameters.
ConstraintsOptimized according to INTERATOM:
Sections 2,4,6: FODO structuresSections 1, 3+4+5 and 7 achromats.Section 8 controls injection.
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Injection optimizationIBL
Not all quadrupoles independent→ 12free parameters.
ConstraintsOptimized according to INTERATOM:
Sections 2,4,6: FODO structuresSections 1, 3+4+5 and 7 achromats.Section 8 controls injection.
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Injection optimizationIBL
Not all quadrupoles independent→ 12free parameters.
ConstraintsOptimized according to INTERATOM:
Sections 2,4,6: FODO structuresSections 1, 3+4+5 and 7 achromats.Section 8 controls injection.
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Injection optimizationIBL
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Injection optimizationIBL
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Injection optimizationIBL
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Injection optimizationTracking at IBL
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Injection optimizationTracking at COSY
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Injection optimizationTracking at COSY
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Injection optimizationTracking at COSY
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Injection optimizationTracking at COSY
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Injection optimizationEmittance measurement
M =
[1 D0 1
]·
[cos(√KL) 1√
Ksin(√KL)
−√K sin(
√KL) cos(
√KL)
]
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Injection optimizationEmittance measurement
M =
[1 D0 1
]·
[cos(√KL) 1√
Ksin(√KL)
−√K sin(
√KL) cos(
√KL)
]
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Injection optimizationEmittance measurement
M =
[1 D0 1
]·
[cos(√KL) 1√
Ksin(√KL)
−√K sin(
√KL) cos(
√KL)
]
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Injection optimizationEmittance measurement
M =
[1 D0 1
]·
[cos(√KL) 1√
Ksin(√KL)
−√K sin(
√KL) cos(
√KL)
]
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Injection optimizationEmittance measurement
M =
[1 D0 1
]·
[cos(√K′L) 1√
K′sin(√K′L)
−√K′ sin(
√K′L) cos(
√K′L)
]
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Injection optimizationEmittance measurement
Plot of beam size squared vs quadrupole strength for Q17, Y axis.
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Injection optimizationEmittance measurement
Fit using first order approximation of M matrix.
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Injection optimizationEmittance measurement
Fit using second order approximation of M matrix.
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Next steps for optimization
The planned upcoming steps for optimizing the injection are:Analyze the injection dipole.Try to find steerer magnets which allow for x and x’ variation of theinjected beam in the stripping foil.Connect IBL and COSY in a simulation for a full tracking including theorbit bump at injection.Try to match phase space at IBL exit with COSY acceptance.Improve the emittance measurement at IBL. Look for other methods.
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References
R. Gebel, R. Brings, O. Felden, R. Maier, S. Mey, D. Prasuhn (2013)20 years of JULIC operation as COSY’s injector cyclotronProceedings of Cyclotrons 2013, Vancouver, BC, Canada.
C. Weidemann (2016)COSY injection and tuningWorkshop on Beam Dynamics and Control studies at COSY.
A. T. Green, Y. M. Shin (2015)Implementation of quadrupole-scan emittance measurement atFermilab’s Advanced Supercomputing Test Accelerator (ASTA)6th International Particle Accelerator Conference.
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Spare slides
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