LLRF Requirement and Parameters at ESS Rihua Zeng, Anders J Johansson LLRF workshop, Hamburg,

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

3 5MW beam power 2.5 GeV protons (H+) 2.9 ms pulses 14 Hzrep rate 50 mApulse current MHz 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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LLRF 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

An universal recipe for LLRF? LLRF Workshop 2011, R. Zeng, A. J. Johansson

To do list LLRF Workshop 2011, R. Zeng, A. J. Johansson

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 … LLRF Workshop 2011, R. Zeng, A. J. Johansson

To be listed list LLRF Workshop 2011, R. Zeng, A. J. Johansson

Issues: multiple cavities control LLRF Workshop 2011, R. Zeng, A. J. Johansson

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

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

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

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

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? LLRF Workshop 2011, R. Zeng, A. J. Johansson

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 LLRF Workshop 2011, R. Zeng, A. J. Johansson

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 LLRF Workshop 2011, R. Zeng, A. J. Johansson

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

Build the prototype LLRF Workshop 2011, R. Zeng, A. J. Johansson

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