1. DC Injector and Space Charge Simulation Status
Colwyn Gulliford, Injector Team

2. Injector work to date (Dec 2016):
Injector Status
Injector work to date (Dec 2016):
Installed in CBETA experimental hall
All subsystems tested
Initial beam recommissioning

3. 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

4. Cathodes Cathode Growth Chamber Cathode Load Lock System
Example QE Scan of Offset Cathode
for High Current Operation
Cathode Characterization

5. DC Electron Source Status
Work to date:
Moved from Electron Source Development Lab
Installed in final position
Baked
HV Conditioned

6. 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

7. 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

8. 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)

9. Beamline Components Beamline Installed (Summer 2016) Dump Temperature
Diagnostics Calibration
Buncher Processed (10/13/2016)

10. Beam Running Summary of results Target, min. Achieved
Cathode: 1% QE, offset 3%
Gun: kV kV
ICM: 1 MeV / cavity 1 MeV - CBETA needs further conditioning
Laser: MHz 10 W
Current: 1 mA 4 mA
Achieved all necessary goals for this phase, ran out of time for push to UPP current

11. Current Activities
Currently Main Linac Cryomodule (MLC) is being prepared to move to it’s final location for the MLC beam test (Wed)

12. 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

13. 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

14. 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.

15. Space Charge Simulations
Parameter
Optimization Range
125 pC Example Solution
Gun Voltage
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
1722 kV / 3 deg
SRF 3 Voltage/Phase
1493 kV / 13 deg
SRF 4 Voltage/Phase
1052 kV / -26 deg
SRF 5 Voltage/Phase
822 kV / -33 deg
Solenoid 1 Current
(0, 6] Amps
4 Amps
Solenoid 2 Current
2.5 Amps
A3 Quad Currents
[-10, 10] Amps
(0.2, 0.3, 1.2, -3.5) Amps
B1 Quad Currents
(4.3, 4.3, -0.9) Amps
MLC Cavity Voltages/Phases
6 MV / (-2, 0, 0, 0, 0, 0) deg
125 pC

16. 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
1791 kV / 4 deg
SRF 3 Voltage/Phase
1576 kV / 16 deg
SRF 4 Voltage/Phase
834 kV / -33 deg
SRF 5 Voltage/Phase
426 kV / -15 deg
Solenoid 1 Current
(0, 6] Amps
3.7 Amps
Solenoid 2 Current
2.4 Amps
A3 Quad Currents
[-10, 10] Amps
(0.1, 0.4, 1.5, -3.6) Amps
B1 Quad Currents
(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

17. 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