1. Boris Keil, PSIDEELS Workshop 201412.5.14 The E-XFEL Button BPM System Boris Keil For the PSI Diagnostics Team Paul Scherrer Institut Paul Scherrer Institut 12.5.14DEELS Workshop 2014

2. Boris Keil, PSIDEELS Workshop 201412.5.14 1 European XFEL L ~ 3400m. 17.5GeV. SASE <0.1nm. Trains of ~2700 bunches @ 10Hz. ~222ns min. bunch spacing. 20-1000pC / bunch. m m m m m m m m m m m m Main linac tunnel Beam distribution, max. 5 undulators User experiments Gun Originally 100-1000pC... Introduction

3. Boris Keil, PSIDEELS Workshop 201412.5.14 2 Introduction E-XFEL BPM Quantities & Types #BPM TypeAperture [mm] PickupRFFEADC & Digital Back-End 73“Cold” button78DESYPSI 31“Cold” re-entrant cavity 78CEA Saclay PSI 228“Warm” button40.5 - 100DESYPSI 117Undulator cavity10DESYPSI 18Transfer line cavity40.5DESYPSI Modular Electronics One digital back-end (FPGA carrier board) and crate type for all BPMs. Two ADC mezzanine types: Button: 12-bit 500MSamples/s Cavity: 16-bit 160MSamples/s Three RF Front-End (RFFE) types: Re-entrant, button, cavity (undulator/TL). Per crate (“MBU” = Modular BPM Unit): 4 button BPMs, or 2 cavity BPMs, or mix.

4. Boris Keil, PSIDEELS Workshop 201412.5.14 33 E-XFEL BPM Requirements Requirements For Complete System (Electronics + Pickup): * For 0.1-1nC determined by PU+Electr.determined by Electr.

5. Boris Keil, PSIDEELS Workshop 201412.5.14 44 Resulting Requirements For Electronics: * For 0.1-1nC Calibrate Stabilize/Calibrate E-XFEL BPM Requirements

6. Boris Keil, PSIDEELS Workshop 201412.5.14 5 Cold & Warm Button BPM "Cold Button" (Linac Cryostats): Aperture 78mm. Warm Button (Warm transfer lines...): Aperture 40.5mm (transfer line), 100mm (beam dump). Version with and without flange (space requirements …). Warm Button: ~3x better position resolution @ low charge than cold button (aperture: 2x, button size: 1.5x). D. Lipka et al. E-XFEL Button BPM Pickups

7. Boris Keil, PSIDEELS Workshop 201412.5.14 6 MBU BPM data processing & storage, RFFE tuning, calibration, … Control system interface: VME, VXS, or front-panel fiber optic links (Ethernet, …). PowerPC in FPGA can run Linux/EPICS. E-XFEL Button BPM System

8. Boris Keil, PSIDEELS Workshop 201412.5.14 77 E-XFEL Button BPM RFFE Diode + S&H capacitor. Discharge: Automatic, or via external trigger. Active temperature stabilization (several sensors + heaters). On-board test/calibration pulser simulates beam signal. Finite-response chirp filter improves low-charge resolution. Two modes: External trigger, or self-trigger (on beam signal) Chirp Filter 63dB gain range, 0.5dB steps

9. Boris Keil, PSIDEELS Workshop 201412.5.14 8 Button BPM RFFE (Cont’d): Input filter Dispersive input filter stretches button pickup pulse. Eases signal handling (linearity/saturation, …). Bandwidth >1GHz: More energy, better low-charge resolution. Notch @ 1.3GHz (avoids noise from high-power RF …) E-XFEL Button BPM RFFE

10. Boris Keil, PSIDEELS Workshop 201412.5.14 9 Button BPM RFFE : PCB Floor Plan Active temperature stabilization Differential coax outputs to ADCs: Low noise. Monitoring of power supply voltage & current E-XFEL Button BPM RFFE

11. Boris Keil, PSIDEELS Workshop 201412.5.14 10 VME P2 Detector, Discharger and Buffer Add-On Modules Calibration Pulser Power Supply Regulators Control I/O Circuits Hot-Swap Controller +5V and +12V RF Amplifier Chain and Step Attenuator RF Shield removed E-XFEL Button BPM RFFE

12. Boris Keil, PSIDEELS Workshop 201412.5.14 11 Chirp Filter Module Hot-Swap Controller  12V Biasing of Calibration Switches E-XFEL Button BPM RFFE

13. Boris Keil, PSIDEELS Workshop 201412.5.14 12 Modular BPM Unit (“MBU”) 19’’ housing, power supply, fans, … Contains 4 button RF front-ends (RFFEs), or 2 cavity RFFEs, or combination. Common digital-back-end FPGA board (GPAC = Generic PSI ADC carrier) + two ADC mezzanines. MBU for two undulator BPMs Control, timing & feedback interfaces: Multi-gigabit fiber optic links. Multi- protocol & baud rate support (PCI-e, Ethernet, …) E-XFEL Button BPM Electronics

14. Boris Keil, PSIDEELS Workshop 201412.5.14 13 Modular BPM Unit (“MBU”) Features Interfaces: 2x SFP+ front, 4x SFP+ rear (6.5Gbps), MPS,... Protocols: PCIe, GigE, E-XFEL timing system, SLS timing system, custom FPGA-FPGA bridge, custom feedback (low-latency data transfer to E-XFEL feedback systems,...). Cooling & temperatures: 8 fans with individual regulation Can keep overall power dissipation constant (measures 230V line power dissipation & has heater at air outlet) All inserted boards: Live insertion, remote power off/on, remote monitoring of supply voltages & currents for each board & whole crate Large number of high-resolution temperature sensors (on RFFEs, ADCs, FPGA board, crate power board,...) Redundant main power supply E-XFEL Button BPM Electronics

15. Boris Keil, PSIDEELS Workshop 201412.5.14 14 E-XFEL Button BPM Electronics MBU Backplane

16. Boris Keil, PSIDEELS Workshop 201412.5.14 15 MBU Fans 8 fans with individual speed control. Removable fan tray.

17. Boris Keil, PSIDEELS Workshop 201412.5.14 16 MBU Air Flow Simulation MBU air flow & temperature simulation

18. Boris Keil, PSIDEELS Workshop 201412.5.14 17 MBU Power & Crate Controller MBU power board with MMC mezzanine MMC mezzanine: Intelligent crate controller/manager (FPGA with SEU-proof configuration & ARM CPU)

19. Boris Keil, PSIDEELS Workshop 201412.5.14 18 8-channels, 1.3 GHz BW, balanced inputs 12-Bit, max. 500 MSa/s, Intersil KAD5512P Internal or external clock Adjustable clock PLL, divider, delays Button BPM ADC Mezzanine Board

20. Boris Keil, PSIDEELS Workshop 201412.5.14 19 "GPAC" FPGA Carrier Board

21. Boris Keil, PSIDEELS Workshop 201412.5.14 20 Button BPM FPGA Firmware

22. Boris Keil, PSIDEELS Workshop 201412.5.14 21 ADC Signal Processing in FPGA Button BPM Signal Processing

23. Boris Keil, PSIDEELS Workshop 201412.5.14 22 ADC Averaging & Resolution

24. Boris Keil, PSIDEELS Workshop 201412.5.14 23 Pickup Signal Stretched by Chirp Filter RFFE output signal, mode2: S&H discharge by external trigger (=standard mode) RFFE output signal, mode1: Automatic S&H discharge by resistor (=non- standard mode e.g. when external trigger is missing) E-XFEL Button BPM Signals

25. Boris Keil, PSIDEELS Workshop 201412.5.14 24 Beam Test Results (FLASH, SwissFEL Test Inj.) Cold button (Ø=78mm) RMS position noise (single bunch): ~30μm @ 20pC ~5μm at 100-1000pC Warm button (Ø=40.5mm) RMS position noise (single bunch): ~11μm @ 20pC ~5μm @ 60pC Warm button, 1 bunch Expect ~3μm at 150-1000pC, to be measured Charge noise <0.05% at 50- 1000pC Average over 40 bunches E-XFEL Button BPM Results

26. Boris Keil, PSIDEELS Workshop 201412.5.14 25 Applications, Status, Outlook... Other applications of E-XFEL button BPM electronics SLS BPM upgrade. For striplines in linac, transfer lines, and for booster button pickups (usually 1 bunch, 1 µs bunch spacing). SwissFEL bunch length monitor ("bunching monitor") after bunch compressor: E-XFEL button BPM electronics connected to output of THz detector front-end (Schottky diode, delivers signal similar to button BPM pickup). Successful test at SwissFEL test injector done. Status & Outlook Currently characterizing & minimizing temperature drift (active temperature stabilization, feed-forward using two temperature sensors per RF channel,...) Schedule: Pre-series for E-XFEL gun commissioning 8/2014, injector commissioning 3/2015, main linac 1st beam end 2016.

27. Boris Keil, PSIDEELS Workshop 201412.5.14 26 Team & Acknowledgements D. Treyer (RF Front-End Electronics) M. Roggli, R. Ditter, R. Kramert (ADC Mezzanine, BPM Crate) R. Baldinger (FPGA Carrier Board) W. Koprek, G. Marinkovic (Software & FPGA Firmware) and: The SwissFEL test injector operation team (Beam test support @ PSI) The DESY diagnostics group: D. Lipka, D. Nölle, S. Vilcins, and many others...

28. Boris Keil, PSIDEELS Workshop 201412.5.14 Paul Scherrer Institut Thank you for your attention!