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

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: 1969894 6/27/2019

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

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

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

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

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

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??? * https://indico.cern.ch/event/719807/contributions/2958886 6/27/2019

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 *ST0919809_03

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

CST Simulation: Compare Terminations

Measurement HV Short-Open:

Measurement HV Short-Short: All HV Ports are Shorted

Spare KFA45 Measurements: 200 MHz 6/27/2019

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

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

Extra Slides 6/27/2019

Spare KFA45 Measurements: 200 MHz 6/27/2019

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

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

CMD5005 CST Interpolations 6/27/2019