1. LLRF Requirement and Parameters at ESS Rihua Zeng, Anders J Johansson LLRF workshop, Hamburg, 2011-10- 20 1

2. 2 Picture from C. Carlile’s presentation at IPAC 2011

3. 3 5MW beam power 2.5 GeV protons (H+) 2.9 ms pulses 14 Hzrep rate 50 mApulse current 352.2 MHz 704.4 MHzRF frequency < 1 W/mbeam losses No accumulator/compressor ring ! Neutrons in 2019 ! Green field site Picture from G. Trahern’s presentation at ICALEPCS11

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5. 2011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson5  More than 200 LLRF stations to be built by 2019 for RFQ, DTL, spoke and elliptical cavities. (One klystron for one cavity.)  Many issues to be addressed  Stringent demands from ESS leads to tough challenges Pulse length: 2.86 ms Rep rate: 14 Hz Current: 50mA

6. An universal recipe for LLRF? 62011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

7. To do list 72011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

8. To learn list FLASHSNSJPARCFerm.CERNLBNLMYHHRA RF Stab0.01%0.5%1% IF freq.250KHz 54 MHz 50 MHz 12 MHz13 MHz20 MHz56 MHz 10 MHz Sample Freq. 1 MHZ 81 MHz 40 MHz 48 MHz54 MHz 56 MHz 80 MHz77.7 MHz 40 MHz Sampl.IQOtherIQOtherIQOtherIQ CrateVME/ATC A VXIcPCIVXIVMEUSBPXI Phase Distr.. Coax Opto 8 … 2011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

9. To be listed list 92011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

10. Issues: multiple cavities control 102011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

11. 11 Picture from S. Peggs’s presentation at IPAC 2011

12.  Klystron Linearization 12  Minimize power overhead. Is 20% enough? Issues: high effeciency 2011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

13. Issues: high availability Availability at ESS 95%  Avoid failures that cause the whole system to fail  Redundancy  Automatically detect  Fast recovery 132011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

14. Issues: others  High intensity  Long pulse  High gradient  Spoke cavity 142011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

15. Design guidelines Fault tolerant architecture and design – Redundancy or adaption? Easy maintenance – Generic design for all LLRF stations? – Modular design? – Auto-config and auto-calibration? Cost effective and long lived – Multiple vendors? – Software defined function by FPGA/DSP implementation for future upgrades? 152011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

16. Main architecture of ESS LLRF FPGA based solution Separate analog mixers for down- and up-conversion I/Q-demodulation and modulation One master oscillator for the whole ESS – Phase reference for RF – Time reference for control, science Global phase reference distribution Coaxial phase reference line EPICS control system 162011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

17. Interesting possibilities: Co-design with Beam Instrumentation – Simplify upkeep of installation – Minimize cost of units for installation and inventory Open Hardware solution – Multiple sources of hardware possible 172011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

18. What to do in the near future Simulation for more detailed parameters and requirement 182011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

19. Build the prototype 192011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson

20. More important, To ask more suggestions for the possible solutions at ESS Many thanks for your attention! 202011-10-20LLRF Workshop 2011, R. Zeng, A. J. Johansson