LCLSII+ A two beam energies machine with 360Hz repetition rate
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LCLSII+ A two beam energies machine with 360Hz repetition rate L. Wang and T. O. Raubenheimer 08/21/2013 LCLSII Physics meeting 8/21/2013 LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
description
LCLSII+ A two beam energies machine with 360Hz repetition rate. L. Wang and T. O. Raubenheimer 08/21/2013 LCLSII Physics meeting. Motivations. - PowerPoint PPT Presentation
Transcript of LCLSII+ A two beam energies machine with 360Hz repetition rate
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
LCLSII+A two beam energies machine with 360Hz
repetition rate
L. Wang and T. O. Raubenheimer
08/21/2013LCLSII Physics meeting
8/21/2013
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Motivations
The goal is study the feasibility of upgrade beyond LCLSII, called LCLSII+, a combination LCLSI and LCLSII with high repetition rate (360Hz) and two beam energies (7.5GeV & 16+ GeV).
We will use the existing accelerator structure (S-Band).
We study 20pC, 150pC and 250pC cases
8/21/2013
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
LCLSII+, 360HZ WITH TWO ENERGIES
gunBC2
2.50 GeV 7.5 GeV
L1S
L2-linac L3-linac
L0
TCAV3
BC1250 MeV
L1X
DL1135 MeV
S10 7.5 GeV
L4-linac L5-linacBC3BL1R56>0
S20
11 GeV 16+ GeV
Layout
LCLSII + LCLSILCLSI and II work together to provide two beam energy simultaneouslyThe current LCLSII beam line provides the low energy beam;De-chirper for low energy beam as an option (if necessary)Part of low energy bunches are continually accelerated through LCLSI accelerator structures to provide high energy beam. Replace the LCLSI BC1 as a bunch lengthener (R56>0) to increase the chirp and reduce the collective effect; in this example, we set E@BC1=250MeV, E@BC2=2.5GeV, E@BC3=11GeV E_high=16GeV. All these can be adjusted and re-optimized in the future.The optimization is first done for the low energy beam, then the same parameters are used for the high energy beam.
Dechirp
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
20pC charge
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
[email protected] beam
Phase L1=-17 degreePhase L2=-28 degreeR56@BC1=-0.05m
Phase L3=-1 degreeR56@BC2=-0.03m
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-0.1 -0.05 0 0.050
0.01
0.02
0.03
0.04
0.05
z /mm
I /kA
Ipk=0.053 kA
After BC1
z=37.300 m (fwhm=122.850)
-3 -2 -1 0x 10
-3
0
0.5
1
1.5
2
2.5
3
3.5
z /mm
I /kAIpk=3.667 kA
After BC2
z=0.674 m (fwhm=2.104)
-3 -2 -1 0x 10
-3
0
0.5
1
1.5
2
2.5
3
3.5
z /mm
I /kA
Ipk=3.667 kA
After L3
z=0.674 m (fwhm=2.104)
-3 -2 -1 0x 10
-3
0
0.5
1
1.5
2
2.5
3
3.5
z /mm
I /kA
Ipk=3.555 kA
Before HXR Undulator
z=0.763 m (fwhm=2.344)
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
20pC@16+GeV beam
Phase L3=-25 degreePhase L4=0 degreeR56@BC3=-6mmR56@BL1=+2.5mm
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-0.1 -0.05 0 0.050
0.01
0.02
0.03
0.04
0.05
z /mm
I /kA
Ipk=0.053 kA
After BC1
z=37.300 m (fwhm=122.670)
-3 -2 -1 0x 10
-3
0
0.5
1
1.5
2
2.5
3
3.5
z /mm
I /kA
Ipk=3.692 kA
After BC2
z=0.674 m (fwhm=2.080)
-3 -2 -1 0x 10
-3
0
0.5
1
1.5
2
2.5
3
3.5
z /mm
I /kA
Ipk=3.692 kA
After L3
z=0.674 m (fwhm=2.080)
-5 -4 -3 -2 -1 0 1x 10
-3
0
1
2
3
4
z /mm
I /kA
Ipk=4.083 kA
Before HXR Undulator
z=490.124 nm (fwhm=1447.641)
Very good beam:High peak current ~4kA, Flat current profile, and Zero chirp.
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Before and after bunch lengthening (20pC)R56=2.5mm
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Before and after BC3 (@11GeV, 20pC)R56=-6mm
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Before undulator,16+GeV @20pC
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-5 -4 -3 -2 -1 0 1x 10
-3
0
1
2
3
4
z /mm
I /kA
Ipk=4.083 kA
z=490.124 nm (fwhm=1447.641)
0 5 10 15-0.06
-0.04
-0.02
0
0.02
0.04
0.06
E/ E
/%
n/103
E/E=0.009% (fwhm=0.012)
Source: lcls_200pC_6MeV_560um.zd
-4 -3 -2 -1 0x 10
-3
-0.05
0
0.05
z /mm
E/ E
/%
E=16.000 GeV, Ne=0.0121010
15-AUG-2013 14:04:26
z=-0.001 mm
lcls_all20pC700um360Hz_16GeV_A_lit.m: LCLS-II @ 0.25 nC with 650 um, 4.5 GeV
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
150pC charge
8/21/2013
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
[email protected] beam
Phase L1=-30 degreePhase L2=-36 degreeR56@BC1=-0.026m
Phase L3=-6 degreeR56@BC2=-0.021m
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-0.3 -0.2 -0.1 0 0.1 0.2 0.30
0.02
0.04
0.06
0.08
0.1
z /mm
I /kA
Ipk=0.098 kA
After BC1
z=0.150 mm (fwhm=0.501)
0.005 0.01 0.015 0.020
1
2
3
4
5
z /mm
I /kAIpk=5.339 kA
After BC2
z=4.345 m (fwhm=13.403)
0.005 0.01 0.015 0.020
1
2
3
4
5
z /mm
I /kA
Ipk=5.339 kA
After L3
z=4.345 m (fwhm=13.403)
0.005 0.01 0.015 0.020
1
2
3
4
5
6
z /mm
I /kA
Ipk=6.324 kA
Before HXR Undulator
z=4.708 m (fwhm=14.148)
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
150pC@16+GeV beam
Phase L1=-30 degreePhase L2=-36 degreeR56@BC1=-0.026m Phase L3=-6 degree
R56@BC2=-0.021mR56@BC3=-7.5mmR56@BL=+3.5mm
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-0.3 -0.2 -0.1 0 0.1 0.2 0.30
0.02
0.04
0.06
0.08
0.1
z /mm
I /kA
Ipk=0.098 kA
After BC1
z=0.150 mm (fwhm=0.501)
0.005 0.01 0.015 0.020
1
2
3
4
5
z /mm
I /kA
Ipk=5.480 kA
After BC2
z=4.345 m (fwhm=13.436)
0.005 0.01 0.015 0.020
1
2
3
4
5
z /mm
I /kA
Ipk=5.480 kA
After L3
z=4.345 m (fwhm=13.436)
0.005 0.01 0.015 0.020
1
2
3
4
z /mm
I /kA
Ipk=4.704 kA
z=3.908 m (fwhm=12.184)
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Beam before/After BL@150pC
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Beam before/after BC3 @150pC
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
Beam at Undulator begin @150pC
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
250pC charge
8/21/2013
LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
[email protected] beam
Phase L1=-22.8 degreePhase L2=-37 degreeR56@BC1=-0.029m
Phase L3=-0.4 degreeR56@BC2=-0.023m
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
250pC@16+GeV beam
R56@BL=3.5mm R56@BC3=-4.5mm
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LCLS-II Accel. Phys. , Lanfa & Tor, SLAC
SummaryThe bunch lengthening section provides adjustable
chirp and reduces the collective effect AdvantagesIt is very promising that LCLSII+ can provide two
beam energies simultaneously with large flexibilities in bunch charge (20-250pC), energy (7~16+ GeV), peak current (>3kA) and energy chirp (zero or slightly positive).
360 HzZero cost
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