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

Boris Keil, PSIDEELS Workshop European XFEL L ~ 3400m. 17.5GeV. SASE <0.1nm. Trains of ~ Hz. ~222ns min. bunch spacing pC / 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 pC... Introduction

Boris Keil, PSIDEELS Workshop 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” button DESYPSI 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.

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

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

Boris Keil, PSIDEELS Workshop 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 low charge than cold button (aperture: 2x, button size: 1.5x). D. Lipka et al. E-XFEL Button BPM Pickups

Boris Keil, PSIDEELS Workshop 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

Boris Keil, PSIDEELS Workshop 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

Boris Keil, PSIDEELS Workshop 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. 1.3GHz (avoids noise from high-power RF …) E-XFEL Button BPM RFFE

Boris Keil, PSIDEELS Workshop 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

Boris Keil, PSIDEELS Workshop 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

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

Boris Keil, PSIDEELS Workshop 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

Boris Keil, PSIDEELS Workshop 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

Boris Keil, PSIDEELS Workshop E-XFEL Button BPM Electronics MBU Backplane

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

Boris Keil, PSIDEELS Workshop MBU Air Flow Simulation MBU air flow & temperature simulation

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

Boris Keil, PSIDEELS Workshop 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

Boris Keil, PSIDEELS Workshop "GPAC" FPGA Carrier Board

Boris Keil, PSIDEELS Workshop Button BPM FPGA Firmware

Boris Keil, PSIDEELS Workshop ADC Signal Processing in FPGA Button BPM Signal Processing

Boris Keil, PSIDEELS Workshop ADC Averaging & Resolution

Boris Keil, PSIDEELS Workshop 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

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

Boris Keil, PSIDEELS Workshop 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.

Boris Keil, PSIDEELS Workshop 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 PSI) The DESY diagnostics group: D. Lipka, D. Nölle, S. Vilcins, and many others...

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