EMMA RF System Alan Wheelhouse, ASTeC, Daresbury Laboratory

1. EMMA RF System Alan Wheelhouse,ASTeC, Daresbury Laboratory Commissioning Workshop Alan Wheelhouse

2. Content • EMMA RF System Overview • Specification • RF System Progress • RF Cavity • High Power RF System • Waveguide Distribution System • LLRF System • Cabling & Connections • Plan Commissioning Workshop Alan Wheelhouse

3. RF System Overview RF Cavities High Power RF Amplifier System Waveguide Distribution System Commissioning Workshop Alan Wheelhouse

4. RF Cavity Commissioning Workshop Alan Wheelhouse

5. Cavity Design & Specification * LLRF + Distribution Commissioning Workshop Alan Wheelhouse

6. RF Cavity Progress Input Coupler construction (Times Microwave) • All 20 cavities delivered • Delays due feed-through delivery from Times Microwave • 14 cavities tested • Tests on-going • Tuners sticking • Sheered copper spring • Spring replaced with lighter force copper spring • Silver plated • Q0≈20000 achieved • Four cavities successfully conditioned • One conditioned to 10kW • Three conditioned to 5kW Cavity construction Tuning range 0- 25 mm Commissioning Workshop Alan Wheelhouse

7. RF Cavity Evaluation • Procedure defined • 14 cavities tested • Rest being tested presently • Pick probe altered on a number of cavities • Optimisation for 40 dB transmission • QL≈10,000 achieved Commissioning Workshop Alan Wheelhouse

8. HIGH POWER RF AMPLIFIER SYSTEM Commissioning Workshop Alan Wheelhouse

9. CPI VIL409 HPRF System • 45kV switch mode power supply • Charging capacitor • CPI IOT VKL-9130B • Tested to 100kW • 5.5MHz bandwidth • Bruker solid state amplifier • Tested to 1.8kW (linear) • WR650 waveguide output • Via a circulator Load Solid State Amplifier Circulator HVPS Charging Capacitor IOT Commissioning Workshop Alan Wheelhouse

10. Factory Acceptance Tests • Factory acceptance tests completed Sept 09 • Power requirements met across the frequency band • 90kW at waveguide • Up to 96kW from IOT • Efficiency > 50% • Gain typically > 20dB • HV pulse droop - 1.25kV • HV ripple 150V @ 44kV • 0.34% (Spec ±0.5%) • Grid voltage ripple 0.4V @ 95V • 0.42% (Spec ±1%) • X-ray levels 10µSv/h seen at the IOT (Spec 2.5µSv/h) • Issue with parameters reading values during off periods! 1.2960GHz 1.3015GHz Commissioning Workshop Alan Wheelhouse

11. Trip Response Times • Trip response time and repeatability issue • Improvements made to the trip circuit • Repeatable trip response times of 80µs achieved • Wire crowbar test successfully performed at 40kV • 6” AWG32 wire with enamel • Stored energy < 18J (Spec 15J) 1 TTL pulse from PIN diode 2 Fault 3 RF pulse 4 Nesting pulse to SS amp Commissioning Workshop Alan Wheelhouse

12. Site Acceptance Tests • Delivered 23rd September 2009 • Installation and site acceptance completed 2nd October 2009 • Power level and frequency responses checked • Issue with EPICS interface • Now resolved • Temporary water fittings used from ALICE • Operations manual being prepared • Draft operations manual supplied 23rd November 2009 Commissioning Workshop Alan Wheelhouse

13. Harmonic and Noise Tests • Input tuned for 1.29875GHz • X-ray levels at 90kW level • 11.2µSv/h seen at the IOT for 1.2960GHz • 9.5Sv/h seen at the IOT for 1.3000GHz • 13µSv/h seen at the IOT for 1.3015GHz • 0.3µSv/h at the cubicle panel • Warning labels to be added to panels Commissioning Workshop Alan Wheelhouse

14. EPICS Interface • EPICS interface working • Labview program modified so that values read zero when off • EPICS controls layout being designed EPICS Dummy Screen Commissioning Workshop Alan Wheelhouse

15. WAVEGUIDE DISTRIBUTION SYSTEM Commissioning Workshop Alan Wheelhouse

16. Waveguide Distribution System Commissioning Workshop Alan Wheelhouse

17. Test Set-Up RIGHT HAND RING Mega hybrid splitter Output cable Bridge section Balance load LEFT HAND RING Transition / Phase shifter Hybrid Commissioning Workshop Alan Wheelhouse

18. Test Set-Up (2) Cable support bracket End launch transition to 7/8 IEC Phase shifter with McLennan motor Balance load Load tuners (isolation trimmers) E plane tuners Angled flange Floor support bracket Directional coupler Adjustable shorting bars Commissioning Workshop Alan Wheelhouse

19. Flange & Gasket Assembly Angled flange Gasket Commissioning Workshop Alan Wheelhouse

20. Phase Shifter Characteristics • Phase shifter resolution • 0.1° = 0.01mm • Full range = 196° • Spec : 180° • As the phase shifter goes further in it approaches the waveguide cut-off Commissioning Workshop Alan Wheelhouse

21. Input Return Loss All output cables were terminated in precision 50Ω loads Input return loss <30dB RIGHT HAND RING LEFT HAND RING Commissioning Workshop Alan Wheelhouse

22. Output Responses Single input tests The 3 dB amplitude difference due to the hybrid splitter All cables and their phase shifters set to produce a co-phase output at the lowest operating frequency • The reference port is 1/2 LHT • Midway phase value after cable trimming • Phase setting, over full bandwidth > 180° AMPLITUDE PHASE Commissioning Workshop Alan Wheelhouse

23. Differential Output Phase Phase shifters set to 0° and 180° Measurements performed with respect to the reference port Demonstrates that full phase shift control can be achieved 0° setting 180° setting Commissioning Workshop Alan Wheelhouse

24. Isolation • Sample of isolation between output ports • Isolation between ports: • > 42 dB (Typically 50 dB) • Optimised using balance load tuners • Worst case path is via the 1/2 hybrid • Strongest coupling to the backward wave or isolation path within the ring • Isolation between half rings is a sum of the hybrid coupling and isolation of the input hybrid splitter Left hand ring Right hand ring Commissioning Workshop Alan Wheelhouse

25. Further Tests • Directional coupler coupling • Forward: -40.5 to -39.8 dB (± 0.35 dB) • Reverse: -40.5 to -39.75 dB (± 0.375 dB) • Spec : 40 ± 0.5 dB • Directional coupler directivity • Forward: > 41 dB • Reverse: > 42 dB • Spec : >40 dB • Some degree of variation of coupling and directivity seen versus phase shift • Due to parasitic interaction with the phase shifter short circuit. • Cable attenuation : 0.048 dB/m at 1.3 GHz Commissioning Workshop Alan Wheelhouse

26. Llrf control SYSTEM Commissioning Workshop Alan Wheelhouse

27. EMMA LLRF • Provides the stabilisation of the accelerating field • Results from tests at 5kW (~140kV) per cavity • Phase 0.0093° (Spec 0.3°) • Amplitude 0.006% (Spec 0.3%) • Libra system developed by I-Tech • Procedures being defined for the timing, cresting and phase setting • Presently under-going additional programming • For the stepper motors and the controllers • For adapting the system to lower sampling frequency (81.25MHz) to aid the timing issue Commissioning Workshop Alan Wheelhouse

28. Cabling & Connections Commissioning Workshop Alan Wheelhouse

29. Cabling & Connections • LLRF rack designed • Build on going • Cabling being pulled in • Cavity • 2 thermal cut-out interlock switches fitted to the water circuits • In series with the water flow trip on the return • Tuner and phase shifter control • Drawings for PCUs and Lantronics systems being drawn up Commissioning Workshop Alan Wheelhouse

30. PLAN Commissioning Workshop Alan Wheelhouse

31. Plan • HVPS Commissioning 1 day • Waveguide Distribution • Installation 3 days • Commissioning 3 days • LLRF • Cable calibration 3 days • Low power tests 1 week • High power tests 1 week • EPICS • Screen layout 1 week • Commissioning In parallel with above work • Timescales dependent on electrical work Commissioning Workshop Alan Wheelhouse