DC Injector and Space
Charge Simulation Status
Colwyn Gulliford, Injector Team
[email protected]
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Injector Status
Injector work to date (Dec 2016):
• Installed in CBETA experimental hall
• All subsystems tested
• Initial beam recommissioning
[email protected]
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Laser
50 MHz System:
• 3 ps pulse length
• 10 Watts
• ~350 fs rms jitter
• 10 µm rms pointing stability
• Tunable Duty Factor: 5E-6 – 1
• Longitudinal Shaping
[email protected]
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Cathodes
Cathode Growth Chamber
Cathode Characterization
[email protected]
Cathode Load Lock System
Example QE Scan of Offset Cathode
for High Current Operation
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DC Electron Source Status
Work to date:
• Moved from Electron
Source Development
Lab
• Installed in final
position
• Baked
• HV Conditioned
[email protected]
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DC Electron Source Status
Work to date:
• Moved from Electron
Source Development
Lab
• Installed in final
position
• Baked
• HV Conditioned
Completed Sept 2016, Stable Operation at 350 kV
[email protected]
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DC Electron Source Status
Work to date:
• Moved from Electron
Source Development
Lab
• Installed in final
position
• Baked
• HV Conditioned
Completed Sept 2016, Stable Operation at 350 kV
[email protected]
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Injector Cryomodule (ICM) Status
ICM Work:
• Installation June 2016
 Cool down to 4K (6/9/2016)
 System check at 2K (6/15/2016)
• ICM is fully tested and ready for RF power
(October 2016)
• Currently operating at 2K (Jan 2017)
 Active pumping of Insulation Vacuum
Vessel
 Active pumping of beamline UHV
 Input coupler N2 purge while ICM is
idle (RF off)
• Tested with beam up to 1000 kV/cavity
(Dec 2016)
[email protected]
CBETA Technical Review, 30 January 2017
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Beamline Components
Beamline Installed (Summer 2016)
Diagnostics Calibration
[email protected]
Dump Temperature
Buncher Processed (10/13/2016)
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Beam Running
Summary of results
Target, min.
• Cathode: 1% QE, offset
• Gun:
350 kV
• ICM:
1 MeV / cavity
• Laser:
5 W @ 50 MHz
• Current: 1 mA
Achieved
3%
350 kV
1 MeV - CBETA needs further conditioning
10 W
4 mA
Achieved all necessary goals for this phase, ran out of time for push to UPP current
[email protected]
CBETA Technical Review, 30 January 2017
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Current Activities
Currently Main Linac Cryomodule (MLC) is being
prepared to move to it’s final location for the MLC
beam test (Wed)
[email protected]
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Current Activities
Currently Main Linac Cryomodule (MLC) is being
prepared to move to it’s final location for the MLC
beam test (Wed)
For the injector:
• Disassembly of diagnostic/dump sections
• New switchyard and merge beam pipe
• Building 4 additional magnets
• Installation of (B1) merger
• Installation of (B2) diagnostic line
[email protected]
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Current Activities
Currently Main Linac Cryomodule (MLC) is being
prepared to move to it’s final location for the MLC
beam test (Wed)
For the injector:
• Disassembly of diagnostic/dump sections
• New switchyard and merge beam pipe
• Building 4 additional magnets
• Installation of (B1) merger
• Installation of (B2) diagnostic line
[email protected]
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Space Charge Simulations
Optimize with (3D) space charge in GPT to match specified beam
sizes and divergence at the end of the first pass of MLC.
[email protected]
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Space Charge Simulations
Parameter
Optimization Range
125 pC Example Solution
Gun Voltage
400 kV
400 kV
Buncher Voltage/Phase
(0, 90] kV / - 90 deg
73 kV / -90 deg
SRF 1 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
870 kV / -6 deg
SRF 2 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
1722 kV / 3 deg
SRF 3 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
1493 kV / 13 deg
SRF 4 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
1052 kV / -26 deg
SRF 5 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
822 kV / -33 deg
Solenoid 1 Current
(0, 6] Amps
4 Amps
Solenoid 2 Current
(0, 6] Amps
2.5 Amps
A3 Quad Currents
[-10, 10] Amps
(0.2, 0.3, 1.2, -3.5) Amps
B1 Quad Currents
[-10, 10] Amps
(4.3, 4.3, -0.9) Amps
MLC Cavity Voltages/Phases
6 MV / (-2, 0, 0, 0, 0, 0) deg
6 MV / (-2, 0, 0, 0, 0, 0) deg
125 pC
[email protected]
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Space Charge Simulations
Parameter
Optimization Range
25 pC Example Solution
Gun Voltage
[300, 400] kV
350 kV
Buncher Voltage/Phase
(0, 90] kV / - 90 deg
49.5 kV / -90 deg
SRF 1 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
1122 kV / -9 deg
SRF 2 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
1791 kV / 4 deg
SRF 3 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
1576 kV / 16 deg
SRF 4 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
834 kV / -33 deg
SRF 5 Voltage/Phase
(0, 1800] kV / [-45, 45] deg
426 kV / -15 deg
Solenoid 1 Current
(0, 6] Amps
3.7 Amps
Solenoid 2 Current
(0, 6] Amps
2.4 Amps
A3 Quad Currents
[-10, 10] Amps
(0.1, 0.4, 1.5, -3.6) Amps
B1 Quad Currents
[-10, 10] Amps
(4.9, 3.1, -0.7) Amps
MLC Cavity Voltages/Phases
6 MV / (-2, 0, 0, 0, 0, 0) Deg
6 MV / (-2, 0, 0, 0, 0, 0) deg
25 pC
[email protected]
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Summary
• Optimized Space Charge simulations performed
• Have KPP ready injector settings from simulations
• Injector rebuilt/recommissioned
• Reached KPP current, energy slightly lower than design
• Preparing for MLC beam tests
[email protected]
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