1. 21 st to 25th September 2009 EMMA RF Systems At Daresbury Laboratory C Beard OVERVIEW OF THE EMMA RF SYSTEM Carl Beard ASTeC, STFC Daresbury Laboratory FFAG 09 21 st to 25 th September 2009

2. EMMA ALICE Injection/ EMMA RF System –Specification –Optimal Solution (unconstrained) RF Systems (Affordable, low(ish) risk solution) –RF Cavity –High Power RF Amplifier System –RF Distribution System –LLRF Commissioning Progress –2 Cavity High Power Tests –Waveguide Acceptance Tests –IOT Amplifier Acceptance Tests EMMA RF Systems At Daresbury Laboratory C Beard

3. ALICE (EMMA SRF Injector) ParameterUnits Nominal Gun Energy200 -350keV Booster Energy7MeV Linac Energy3-13MeV RF Frequency1.3GHz Nominal Bunch Charge10 - 80pC Maximum Train LengthSingle Bunch Maximum Bunch Repetition Rate1-10Hz 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

4. EMMA Optimal Solution Unconstrained by Size Cost Single SS Amplifier driving each cavity Broadband No RF distribution required Phase locked loop per cavity/amplifier. Improved Phase and Amplitude control Parts would be cheap and quick to replace. SS Amp + LLRF 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

5. RF System Overview High Power RF Amplifier System Waveguide Distribution System RF Cavities Machine ParametersValueUnits Frequency1.3GHz Number of Straights21 Number of Cavities19 Total Acc per Turn2.3MV Upgrade Acc per Turn3.4MV Beam Aperture40mm RF Pulse Length1.6mS RF Repetition Rate5-20Hz Phase Control0.3° Amplitude Control0.3% 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

6. Cavity Design & Specification ParameterValue Frequency (GHz)1.3 Shunt Impedance (MΩ)2.05 QoQo 20,000 R/Q (Ω)100 Tuning Range (MHz) -4.0MHz to +1.5MHz Vacc (kV) Pdiss (kW)3.68.5 Ptot incl 30% Overhead* (kW)4.711.1 Total Ring Power (kW) 89.3 210.9 * LLRF + Distribution 120 180 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

7. RF Cavity High Qo required ~20000 for 180kV –Compact ring - cavity length restricted to 110mm –Large beam aperture – 40mm Tuner design provides 10MHz tuning range (reduce cost) Input coupler – coaxial transmission Loop coupling Niowave supplying 20 cavities Four cavities successfully conditioned –One conditioned to 10kW –Three conditioned to 5kW Crosstalk seen on the pick-up probe –Resolved by rotating couplers by 180° Input Coupler construction (Times Microwave) Tuning range 0- 25 mm Cavity construction 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

8. Cavity issues Cross Talk between Coupler and pickup –Measured and Simulated –Artificially high Q –All cavities delivered have been reset. Tuner RF Spring –Over time mechanism jamming 21 st to 25 th September 2009EMMA RF Systems at Daresbury Laboratory C Beard 180 o Rotation

9. High Power RF Amplifier IOT Circulator Load HVPS Solid State Amplifier Charging Capacitor 3, 19” racks HVPS and charging capacitor CPI IOT VKL-9130B –Tested to 100kW (broadband) Bruker solid state amplifier –Tested to 1.8kW (linear) 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

10. High Power RF Amplifier IOT gain typically >21dB Solid state amplifier gain typically 61.8 dB On-board Microprocessor-based controller, –Accepts command inputs –Provide status outputs –Status reporting is near a “real-time” rate Acceptance tests September 2009 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

11. Waveguide Distribution Scheme Hybrid Phase Shifter 7/8EIA Coaxial Cable Cavity Power split from the IOT with a 3.1dB hybrid –10 RF cavities anti-clockwise –9 RF cavities clockwise Hybrid and Phase Shifter –H plane coupling method –Capacitive E plane tuner Amplitude control –RF power from the IOT –Cavity frequency Phase control –Cable length (fixed) –Phase shifter System has completed its factory acceptance tests and has been delivered 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

12. Waveguide Distribution Scheme Compact Transmission Line –Fixed RF split Varies along the line –40 dB directivity between ports –In-line circulator and load –Phase shifter –Directional coupler to monitor Fwd / Ref power –Transformer from Waveguide TE 1,0 mode to coaxial TE 1,1 mode Hybrid & Phase Shifter Example; 7 dB Splitter = 80% Transmission 20% of the power to the cavity. 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

13. 21 st to 25 th September 2009EMMA RF Systems at Daresbury Laboratory C Beard High Power Tests High Voltage Power Supply IOT Waveguide Libera LLRF Control 2 CavityTest –DL Developed Capacitor charger power supply –CPI IOT 30 kW (cw) –Libera LLRF Controls system –Q-Par Angus – 3 dB hybrid –2 Niowave Cavties Tested to 5 kW per cavity –Cross talk between cavity and IOT Output Cavity –Circulator installed –Controlled to better than Design Specification –Simplest system 2 RF Cavities Solid State Drive Water Cooling

14. EMMA LLRF Provides the stabilisation of the accelerating field Controls the amplitude and phase each of the cavities via; –Pick-up probes in the cavities –forward and reverse directional couplers on each of the hybrid and phase shifter waveguide modules, –the forward and reverse power levels from the IOT, before and after a circulator, –the forward and reverse power levels from the solid state driver LLRF tests performed using an I-Tech Libra system –In-built FD Network analyser –Rapidly understand problems with the transmission line, without connecting other equipment 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

15. LLRF 2 Cavity Commissioning Performance achieved at 5kW (~150kV) per cavity –Phase: 0.0093º (spec is 0.3º) –Amplitude: 0.006% (spec is 0.3%) –Achieved with only 2 cavities Degradation as more cavities are included in the system Simulink model show it is possible, however Final operating parameters will only be demonstrated once the 19 cavity system is built. Issue seen with a double hump response –Resolved with the inclusion of a circulator Libera Unit Delivered – Software due 21 st to 25 th September 2009EMMA RF Systems at Daresbury Laboratory C Beard No circulator Circulator

16. 21 st to 25 th September 2009EMMA RF Systems at Daresbury Laboratory C Beard

17. Summary EMMA Design completed Procurement –RF Cavities 16 (20) delivered Re-configured –Waveguide distribution delivered –IOT Acceptance Tests completed Delivery Due End September –LLRF System Delivered Final iterations on the Software EMMA RF installation commencing October 2009… …RF Commissioning. 21 st to 25 th September 2009EMMA RF Systems At Daresbury Laboratory C Beard

18. Acknowledgements STFC –Neil Bliss, Adam Bozson, Peter Corlett, Paul Dickinson, Ken Dilworth, Andy Goulden, Philippe Goudket, Steve Griffiths, Clive Hill, Peter McIntosh, Andy Moss, Bruno Muratori, Joe Orrett, Yuri Saveliev, Tom Weston, Alan Wheelhouse. I-Tech & DimTel – LLRF Niowave Inc – Cavity Q-Parr Angus – RF Distribution CPI – RF Amplifier 21 st to 25 th September 2009EMMA RF Systems at Daresbury Laboratory C Beard