1. PS KFA45_17 Wire Measurements and Simulation
Branko Popovic
Thanks to Alvaro Colomo & TE-ABT-PPE
6/27/2019

2. Overview New KFA45 magnet (KFA45_17)*
Provides fast beam deflection for injection into PS
New magnet updated for 2.0 GeV beams (1.4 GeV for old magnet)
Overall very similar to old KFA45
Larger Ferrites
Slight Changes in Module Frame Geometry
EM Measurements
Wire Measurements
Probe Measurements
Compare to Simulation Results
* ECR:
6/27/2019

3. 3D CST Model of the KFA45_17
Single Module
6/27/2019

4. Wire Measurements
Measured with one HV hookup shorted and the other open
‘Short-Open’
225 Ohm match resistor*
Measured the spare as well
‘Short-Short’
Shorted HV Hookups
* Different resistors from one measurement to the next, same values just not same exact ones
6/27/2019

5. Initial Simulation vs Measurement
Measured Modes (6 MHz & 16.5 MHz)
Simulated mode at 73 MHz appears in both Wakefield and S-Parameter Wire Simulations
Simulated Mode
(73 MHz)
HV cables are all shorted
(Short-Short)
6/27/2019

6. Simulated Mode at 73.5 MHz
Simulated mode at 73 MHz appears in both Wakefield and S-Parameter Wire Simulations
Ground plates
Ground plates
6/27/2019

7. 3 ‘Mystery’ Modes: 2 Modes not seen in Wakefield or Wire Simulations
6 MHz &16.5 MHz
One Mode not seen in Measurement
73.5 MHz
Approaches
Double Checked the Ferrite Material Definition (CMD5005)
Interpolation?
Checked Solver
Discrete vs Frequency Reduced Order Mod
Probe Measurements
6/27/2019

8. Approach to Inconsistencies between Simulation and Measurements
Confirming the Ferrite Definition (Interpolation Issues?)
Wanted to confirm CST is correctly handling imported permeability values (CMD5005)
Double interpolation
First interpolation is taking data from user file
Second interpolation is the Frequency Reduced Order Model
Simulated Ferrite Definition in shorted Ferrite Holder
Imported simulated SNP file into Python Code* to generate permeability values
→ Same permeability curve generated
Checking the CST Solver Method
Discrete vs Frequency Reduced Order Model
Discrete solver takes points directly off first interpolated mu curve
Frequency Reduced Order Model does a 2nd Interpolation
→ No difference between solvers
Wire possibly over coupling to 73 MHz mode?
Try Probe Measurements
→ No measurements possible below 200 MHz (noise floor)
Geometric Element missing??? *
6/27/2019

9. Missing Element: Transition Pieces
Connecting all the grounding rails from one module to the next (4 modules) to the tank body on either side
Impedance Reduction
Ground plates
Grounding Rails for Ground Plates
Transition Piece*
6/27/2019
*ST _03

10. Schematic Solver Link to CST Solver Result
All HV Cables Shorted (Short-Short)*
*Same as 3D Short
Link to CST Solver Result
6 Port S-Parameters (.s6p)
For the kicker one of the two HV Hookups are always grounded
Hence its 6 port not 10 port
HV cables terminated with Ideal Absorbers +
*Same as Waveguide Ports
HV Hookups
(Ports 3-6)
HV Cables with Open (Short-Open)
Wire Connection
(Port 1)
Wire Connection
(Port 2)
6/27/2019

11. CST Simulation: Compare Terminations

12. Measurement HV Short-Open:

13. Measurement HV Short-Short: All HV Ports are Shorted

14. Spare KFA45 Measurements: 200 MHz
6/27/2019

15. Re-evaluate other KFA Simulation Models
With Transition Pieces:
KFA4
KFA13 & KFA21*
*Identical
KFA13
6/27/2019

16. Conclusion & Future Work
Simulation model verified via measurement
Transition piece eliminates major mode at 73 MHz
Re-evaluate other KFA models with transition piece
CST schematic model incorporates HV ports
Possibility of incorporating effects of cable loading?
6/27/2019

17. Extra Slides
6/27/2019

18. Spare KFA45 Measurements: 200 MHz
6/27/2019

19. 3D CST Model of the KFA45 (Pre-LS2)
6/27/2019

20. Pictures of Spare KFA45
Note already grounded on one of two terminations
6/27/2019

21. CMD5005 CST Interpolations
6/27/2019