Paul Scherrer Institut The EXFEL Button BPM System

Paul Scherrer Institut The E-XFEL Button BPM System Boris Keil For the PSI Diagnostics Team Paul Scherrer Institut Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

Introduction European XFEL • L ~ 3400 m. 17. 5 Ge. V. SASE <0. 1 nm. • Trains of ~2700 bunches @ 10 Hz. • ~222 ns min. bunch spacing. • 20 -1000 p. C / bunch. Originally 100 -1000 p. C. . . Main linac tunnel Gun m Boris Keil, PSI Beam distribution, max. 5 undulators m m m DEELS Workshop 2014 m m User experiments m m 12. 5. 14

Introduction E-XFEL BPM Quantities & Types # BPM Type Aperture [mm] Pickup RFFE ADC & Digital Back-End 73 “Cold” button 78 DESY PSI 31 “Cold” re-entrant cavity 78 CEA Saclay PSI 228 “Warm” button 40. 5 - 100 DESY PSI 117 Undulator cavity 10 DESY PSI 18 Transfer line cavity 40. 5 DESY PSI Modular Electronics • One digital back-end (FPGA carrier board) and crate type for all BPMs. • Two ADC mezzanine types: Button: 12 -bit 500 MSamples/s Cavity: 16 -bit 160 MSamples/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. Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL BPM Requirements For Complete System (Electronics + Pickup): * For 0. 1 -1 n. C Boris Keil, PSI determined by PU+Electr. DEELS Workshop 2014 determined by Electr. 12. 5. 14

E-XFEL BPM Requirements Resulting Requirements For Electronics: * For 0. 1 -1 n. C Boris Keil, PSI Stabilize/Calibrate DEELS Workshop 2014 Calibrate 12. 5. 14

E-XFEL Button BPM Pickups 5 Cold & Warm Button BPM • "Cold Button" (Linac Cryostats): Aperture 78 mm. • Warm Button (Warm transfer lines. . . ): Aperture 40. 5 mm (transfer line), 100 mm (beam dump). • Version with and without flange (space requirements …). • Warm Button: ~3 x better position resolution @ low charge than cold button (aperture: 2 x, button size: 1. 5 x). D. Lipka et al. Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM System 6 MBU BPM data processing & storage, RFFE tuning, calibration, … Control system interface: VME, VXS, or front-panel fiber optic links (Ethernet, …). Power. PC in FPGA can run Linux/EPICS. Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM RFFE Chirp Filter 63 d. B gain range, 0. 5 d. B steps • 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) Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM RFFE 8 Button BPM RFFE (Cont’d): Input filter • Dispersive input filter stretches button pickup pulse. • Eases signal handling (linearity/saturation, …). • Bandwidth >1 GHz: More energy, better low-charge resolution. Notch @ 1. 3 GHz (avoids noise from high -power RF …) Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM RFFE 9 Button BPM RFFE : PCB Floor Plan Differential coax outputs to ADCs: Low noise. Active temperature stabilization Monitoring of power supply voltage & current Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM RFFE 10 Power Supply Regulators Control I/O Circuits Calibration Pulser Detector, Discharger and Buffer Add-On Modules Hot-Swap Controller +5 V and +12 V VME P 2 RF Amplifier Chain and Step Attenuator RF Shield removed Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM RFFE 11 Hot-Swap Controller 12 V Chirp Filter Module Biasing of Calibration Switches Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM Electronics 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 Boris Keil, PSI Control, timing & feedback interfaces: Multi-gigabit fiber optic links. Multiprotocol & baud rate support (PCI-e, Ethernet, …) DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM Electronics 13 Modular BPM Unit (“MBU”) Features • • Interfaces: 2 x SFP+ front, 4 x SFP+ rear (6. 5 Gbps), MPS, . . . Protocols: PCIe, Gig. E, 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 230 V 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 Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM Electronics 14 MBU Backplane Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

MBU Fans 15 8 fans with individual speed control. Removable fan tray. Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

MBU Air Flow Simulation MBU air flow & temperature simulation Boris Keil, PSI 16 MBU air flow & temperature simulation DEELS Workshop 2014 12. 5. 14

MBU Power & Crate Controller MBU power board with MMC mezzanine Boris Keil, PSI 17 MMC mezzanine: Intelligent crate controller/manager (FPGA with SEU-proof configuration & ARM CPU) DEELS Workshop 2014 12. 5. 14

Button BPM ADC Mezzanine Board • 8 -channels, 1. 3 GHz BW, balanced inputs • 12 -Bit, max. 500 MSa/s, Intersil KAD 5512 P • Internal or external clock • Adjustable clock PLL, divider, delays Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

"GPAC" FPGA Carrier Board Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

Button BPM FPGA Firmware Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

Button BPM Signal Processing 21 ADC Signal Processing in FPGA Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

ADC Averaging & Resolution Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM Signals Pickup Signal Stretched by Chirp Filter RFFE output signal, mode 1: Automatic S&H discharge by resistor (=nonstandard mode e. g. when external trigger is missing) Boris Keil, PSI RFFE output signal, mode 2: S&H discharge by external trigger (=standard mode) DEELS Workshop 2014 12. 5. 14

E-XFEL Button BPM Results Beam Test Results (FLASH, Swiss. FEL Test Inj. ) Cold button (Ø=78 mm) RMS position noise (single bunch): ~30μm @ 20 p. C ~5μm at 100 -1000 p. C Warm button (Ø=40. 5 mm) RMS position noise (single bunch): ~11μm @ 20 p. C Expect ~3μm at 150 -1000 p. C, ~5μm @ 60 p. C to be measured Warm button, 1 bunch Charge noise <0. 05% at 501000 p. C Average over 40 bunches Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

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). • Swiss. FEL 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 Swiss. FEL 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 1 st beam end 2016. Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

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 Swiss. FEL test injector operation team (Beam test support @ PSI) • The DESY diagnostics group: D. Lipka, D. Nölle, S. Vilcins, and many others. . . Boris Keil, PSI DEELS Workshop 2014 12. 5. 14

Paul Scherrer Institut Thank you for your attention! Boris Keil, PSI DEELS Workshop 2014 12. 5. 14