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SPX Low-level RF System WBS APS-U1.03.03.02 (SPX) WBS APS-U1.02.01.03.02 (SPX0)

SPX Low-level RF System WBS APS-U1.03.03.02 (SPX) WBS APS-U1.02.01.03.02 (SPX0). Lawrence Doolittle Staff Engineer/Scientist Engineering Division/Lawrence Berkeley National Laboratory DOE Lehman CD-2 Review of APS-Upgrade 4-6 Decem ber 2012. SPX LLRF Team.

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SPX Low-level RF System WBS APS-U1.03.03.02 (SPX) WBS APS-U1.02.01.03.02 (SPX0)

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  1. SPX Low-level RF SystemWBS APS-U1.03.03.02 (SPX)WBS APS-U1.02.01.03.02 (SPX0) Lawrence Doolittle Staff Engineer/Scientist Engineering Division/Lawrence Berkeley National Laboratory DOE Lehman CD-2 Review of APS-Upgrade4-6 December 2012

  2. SPX LLRF Team DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 SPX LLRF R&D is a collaboration between ANL and LBNL. The LLRF collaboration team includes

  3. Outline DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Cost, Schedule, Scope • Cost summary, • Requirement, specifications, • Design • Methods, implementation, • Interfaces, system plans • Status • Hardware/code development • Near-term tests • Summary

  4. SPX LLRF Scope - Cost, purpose, and requirement Table 2: Tolerances for SPX for cross-phase operation on zero crossing. • Requirement • Closed-loop control of cavity field rf, and phase drift calibration • Facilitates cavity resonance control with rf data through EPICS • Interface with I/OC host and MPS interlock DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 Cost Summary and WBS Purpose - stabilizes the cavity rf field to meet SPX RF error Tolerance

  5. SPX LLRF Design – RF Stabilization Methods DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Use of two closed-loop controls • FAST RF-FEEDBACK LOOP - targets random, wide-band perturbations, including cavity microphonics, through fast cavity field regulation. • CALIBRATION LOOP – targets slower phase drifts in rf signal channels; detects w/ pilot-tone, feeds the drifts data back to phase set-point for correction. • Facilitate cavity resonance control of Tuner Loopwith RF data 5

  6. RF Stabilization Methods(1) fast RF feedback loop, model Analysis model in continuous-time DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 Implementation model in discrete-time • Standard, fast RF-feedback loop provides a wide-band control of cavity field with • Proportional Control term to cover the full-bandwidth of 0.1Hz ~ 271kHz, and • Integral control action to add emphasis on low end from DC to 1kHz, 20~40dB suppression • Proven FPGA code implementation (SNS, in operation since 2006), enhanced with • Non-I/Q sampling scheme for improved measurement/control precision • 18-bit precision of internal signal data processing • Multi-channel digital radio receiver for processing rf and calibration tone frequencies

  7. RF Stabilization Methods (2) channel calibration loop • Phase drift detection algorithm • where • ΦREF,CAV-the calculated phase difference between cavity and ref. • ΦRF_REF, ΦRF_CAV-measured phase of cavity and reference signal • ΦCAL_U_REF, ΦCAL_L_REF-measured phase of upper and lower side-band of Cal-Tone signal in Reference cable. • ΦCAL_U_CAV, ΦCAL_L_CAV-measured phase of upper and lower side-band of Cal-Tone in Cavity field cable. DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Closed-loop control of phase drift in rf signal channels by • Inject calibration tone in rf signal transmission channels for phase drift detection, then • Real-time compensate the detected drift by applying correction to phase set-point in FPGA. • Technology developed in LBNL, demonstrated at LCLS/SLAC • Phase stabilization performance of 3~15 milli-deg. was demonstrated and reported (Byrd and Huang et al., BIW’10).

  8. LLRF Tuner Loop Support Output RF vector spinning driven by LLRF’s DDS (actual signal data) Output RF vector spinning governed by cavity resonance detune (actual data) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Performs cavity resonance locating (during startup) by 2 methods: • frequency sweep with LLRF DDS mode (digital freq. synthesis) • Cavity resonance tracking with LLRF digital SEL control mode (Self-Excited-Loop). LLRF in DDS control mode LLRF in SEL control mode • Facilitates EPICS closed-loop control of cavity resonance by sending rf data to I/OC for computing cavity detune.

  9. SPX LLRF Controller – Hardware & Interfaces DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 R&D Model for SPX0 4+2 rf inputs for CAVITY, REF, FWD, REF, KLYOUT, KLY_IN Two RF outputs for KLY_DRV, CAL_OUT One high-speed SDI to I/OC host One ext. timing trigger input One internal timing trigger output One serial interface to phase stabilizer board One 3-bit interface with MPS interlock Considered additions in Production Model Real-time SDI interface (RTDL) Larger 7-series FPGA Additional rf I/O channels Expanded I/O for more SRF exception handling Optical isolation between AFE and DFE 9

  10. LLRF System – Integration with Controls vs. data I/O High-level controls of LLRF via. writing control data to LLRF registers in FPGA High-level controls read back rf and status data for analysis and uses in other processes LLRF DRV wfm Cav. Field wfm Phase Ref. wfm Other signals FWD PWR wfm DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 The digital LLRF merges with SPX Controls as a device of EPICS I/OC

  11. LLRF System – Site installation planwith 8 LLRF controllers, 2 combined sync-heads, and Real-time data links x4 in Sector-5 (x2 in SPX0) x4 in Sector-7 (absent in SPX0) DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 11

  12. Status – development is actively taking place in both labs. FWD PWR DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Key component - Cavity field controller base model has been designed, and all four units needed for SPX0 have been constructed and tested, (one has been delivered for test with SRF at ATLAS) • Supporting components – LLRF Frequency generation chassis, cavity emulator have been designed, constructed, and delivered • Two code versions have been developed and released • 1st of the two core-functions – multi-channel LLRF digital transceiver with RF-Feedback Control, released and tested in October, 2011. • 2nd core-function - phase drift detection/correction, finished in July 2012, currently under tests.

  13. Status – code development, management DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 Currently using two source-code version-controlled repositories,both shared with LBNL's APEX project. Gateware:  369 commits from 3 authors since June 2011  260 files (158 Verilog), 17163 lines, large number of unit and system tests  81 files, 5726 lines specific to SPX  35 files, 2332 lines specific to APEX Software (USB communications up through EPICS driver and test GUI):  339 commits from 4 authors since April 2011  600 files (some duplicate), 60877 lines  25 files,  798 lines specific to SPX  61 files, 2175 lines specific to APEX(Both code bases have much longer histories, these dates just correspondto their entry into our version control system (git)) 13

  14. Status – hardware development DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Hardware constructed (includes spares and LBNL development copies): • 4 LLRF/Phase Control chassis • 2 LO/Frequency Generation chassis • 2 Cavity Emulator chassis • Documentation generated at LBNL and provided to ANL includes • Chassis schematics, BOM, and construction packets for fivekey circuit boards (LLRF4 and Expansion board, up and downconverter, and LO driver) 14

  15. Status – Core component: LLRF-Timing controller unit Expansion Board (Sync-head Monitor) LLRF DRV LLRF Digital Transceiver Board FWD PWR LO Dist. module Timing Digital Transceiver Board Fiber Optics Beat-Tone Module DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 Construction of LLRF-Timing controller chassis with both LLRF digital transceiver and Timing transceiver board integrated.

  16. Status – performance tests: RF feedback loop (1) • This result indicates that LLRF electronics has a noise floor low enough to allow rf phase measurement resolution down to milli-degree level – a necessary condition for achieving a control precision within the total error budget • An important basis for using LLRF measurement data for subsequent system characterization. DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Initial result of rf input channel phase noise floor measurement (AFE+DFE, with 2011 FPFA code version) • Differential between 2 input channels • <0.002 deg, integrated over 0.1Hz~1kHz; • <0.007 deg, integrated over 0.1Hz~100 kHz • Single channel relative to reference clock: • ~0.002 deg, integrated over 0.1Hz~1kHz; • <0.006 deg, integrated over 0.1Hz~100 kHz

  17. Status – performance tests: RF feedback loop (2) • Total LLRF system noise floor level measured by looping LLRF drive back to cavity input ch. (thus the measured phase noise is relative to reference/clock) • Measurement BW: 1Hz~46kHz, @ 2/3 F-S level, no klystron • 10.5 mdeg rms in open-loop • 4.5 mdegrms in closed-loop mode, no cavity, loop gain~=1 Phase noise spectra, open-loop Phase noise spectra, closed-loop DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

  18. Status – performance tests: RF feedback loop (3) Bench measurement of differential phase error in closed-loop control • Two LLRF controllers drive two cavity emulators, both run on a common clock and LO, thus only the differential error by the two LLRF controllers is seen. • Measured ~6 mdeg rms differential phase error integrated over 0.1Hz~3kHz, and ~20 mdeg to 1MHz. DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

  19. Status – performance tests with HLRF klystron (1) • In preparation for coming-up Horizontal Cold Tuner Test at ATLAS, a complete LLRF test system rack was built, and tested with high-power RF klystron in EAA area. • Exercised GDR open-loop, closed-loop control with SRF cavity emulator, demonstrated a good control stability. • Effectiveness of rf loop in suppressing the phase noise of klystron HV power supply was also demonstrated (results in following slides). HLRF Klystron LLRF system test rack DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 19

  20. Status – performance tests with HLRF klystron (2) Spectrum and accumulated value of cavity rf phase noise when LLRF is in OPEN-LOOP control mode DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 20

  21. Status – performance tests with HLRF klystron (3) Spectrum and accumulated value of cavity rf phase noise when LLRF is in CLOSED-LOOP control mode DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 21

  22. Status – performance tests: channel calibration loop This exercise proved the calibration loop correctly detect and identify the phase drifts in the cables, and compensate them by applying the corrections to the phase set-point. Set-point change CAVITY-RF REF-RF Ref Cable drift CAVITY-CAL-L DRV-RF PHASE_REF FINAL ERR=CAV-(PHASE_REF+SP) Cal-tone Cable drift Cav. Cable drift DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 FPGA Code for calibration loop was completed in July 2012, and shortly after Function tests with simulated cable drifts were exercised at LBNL for verification Elaborated tests in ANL will follow

  23. Technical Risks & Mitigation 23 DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012 • Overall, technical risk of LLRF area is low, and so in the costs and schedule, due to current development status we have, and to the fact that the key technology of digital LLRF control and phase drift calibration from LBNL is proven, and demonstrated (SNS, SLAC). • Concerns of unknown levels of perturbations • environment EMI, • beam loading, • Cavity microphonics (including helium pressure, vibrations, tuner jolt) • Mitigation - Collect data during development, work with the related-system developers to minimize these perturbations as much as possible.

  24. SPX Low Level Radio Frequency Scope and WBSU1.02.01.03 & U1.03.03 Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012

  25. SPX Low Level Radio Frequency Obligation Profile U1.02.01.03 & U1.03.03 Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012

  26. SPX R&D and Production Milestones U1.02.01.03 & U1.03.03 Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012

  27. SPX Low Level Radio Frequency Milestones U1.02.01.03 & U1.03.03 Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012

  28. SPX Low Level Radio Frequency Summary Schedule U1.02.01.03 & U1.03.03 Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012

  29. SPX Low Level Radio Frequency BOE Contingency U1.02.01.03 & U1.03.03 Director's CD-2 Review of the Advanced Photon Source Upgrade Project 11-13 September 2012

  30. Summary • The total cost for LLRF is $3,982k. • SPX LLRF R&D is progressing on schedule. • LLRF controller hardware has been designed, and all four units have been constructed. • Two LLRF code versions are developed and delivered to support near-term tests: rf-loop/calibration-Loop/Self-excited-loop. • Test results of current stage show llrf phase errors within tolerance. • Supporting documents (ESD, ICD) completed. • LLRF test stand for supporting SRF Horizontal Tuner Test at ATLAS has been built, and deployed at ATLAS. • We are ready for CD-2. Thank you DOE Lehman CD-2 Review of the APS Upgrade Project 4-6 December 2012

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