0 1 Beam control upgrade F Bertin H

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1 Beam control upgrade F. Bertin, H. Damerau, D. Perrelet, N. Pittet, S. Rey, B. Woolley Longitudinal limitations with LIU-PS RF upgrades and mitigation strategy 21/09/2018

Introduction • • Present beam control poses no performance limitation Long term maintainability must be assured after LS 2 • • First upgraded systems commissioned after LS 1 Step-by-step migration to upgraded beam control since Objective for LS 2: ® Renovate remaining analogue parts of beam control ® Converge to single beam control handling all beams 2

3 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

4 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

Completed upgrades 2014 • • 10 MHz 1 -turn delay feedback, digital voltage control loops Reduced transient beam loading on LHC-type beams 2016 • • Dipole coupled-bunch feedback with tag-less multi-harmonic sources White Rabbit-based revolution frequency program 2017 • Tag-less multi-harmonic sources for all beam controls • Extension of 10 MHz feedback to cavity controller including RF source ® No RF link between beam control and cavity controller: clock and sync. 2018 • Universal cavity return sum based on multi-harmonic sources • Combines return of eleven 10 MHz cavities to common vector sum ® Valid for any harmonic number, now common to all beam controls ® Completed upgrades become integral parts of beam control after LS 2 ® 1. 5 years operational experience with tag-less resynchronization scheme 5

2 nd generation multi-harmonic sources • Beam synchronous numerical RF sources for down/up-conversion Sync. fclk h. RF Fa Counter Fh 1 f sin h. RFF + f F CORDIC cos F F h=1 t Fa = Fa, position + Fa, offset f = 2 phfrevt + foffset F h. RF t t t Fa, position : azimuth position, Fa, offset : global offset t : delay, h. RF foffset : phase offset ® Synchronized only once at fixed frequency before injection ® Programmable harmonic, azimuth, phase and (virtual) delay ® Programmable azimuth and phase jumps: transition feed-forward and bunch rotations ® Firmware block for FPGA, not necessarily a physical source 1 st generation MHS: R. Garoby, PS/RF/Note 97 -10 6

7 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

MHS-based cavity return sum 8 • Undo de-phasing of cavity return signals: inverse MHS system ® All cavities back to a common reference phase ® Universal cavity return sum sin(hfrevt + h. F) from MHS Cavity return sin(hfrevt) Low-pass filter ADC DAC Low-pass filter cos(hfrevt + h. F) from MHS Return sum cos(hfrevt) ® Signal processing chain per cavity return ® Dephasing band-pass filter, programmable like MHS: h, f, F, t ® Simple RF power combiner for vector sum

MHS-based cavity return sum 9 • Undo de-phasing of cavity return signals: inverse MHS system h, f, F, t Master DDS h=256 h, F RF to cavity 11 MHS … MHS-CRS RF to cavity 96 MHS-CRS • Cavity return vector sum at any harmonic number • Programmable fast phase changes • Transition (180°-2 f. S), bunch stretching at unstable phase (± 180°), ® Fully commissioned with all beam controls during 2018 start-up ® Significant simplification of remaining analogue beam controls

10 Deployment status of MHS • MHS system compatible with present beam controls • • All operational beams migrated MHS Few 1 st generation MHS still running ® Harmonic number measurement ® 10 MHz coupled-bunch feedback New system almost ready New LLRF during LS 2 • Already more than 150 MHS in total (09/2018) Function Source Modules Front-ends 10 MHz cavity controllers 11 11 4 10 MHz Coarse tuning 4 1 1 Beam control 9 4 1 Coupled-bunch feedback 20 4 1 10 MHz cavity return sum 22 4 1 Radial position detection 6 3 1 115 (!) 5 2 40 MHz and 80 MHz MHFB

11 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

Master clock for MHS system • Generation and distribution of synchronous clocks and sync. pulses to all slave multi-harmonic sources • Present system based on set of NIM modules ® Difficult to maintain and extend beyond 256 frev • New design based on LHC-type VME or m. TCA ® Higher clock frequency, up to 2048 frev ® Integrated divider with customisable 2 nfrev • White Rabbit for data and clock transmission ® Possibility to synchronize with new SPS beam control foreseen 12 B. Woolley

Prototype master clock for MHS system B. Woolley ® Test set-up being prepared in view of final development ® Beam test during 2018 ion run: frev reception and clock regeneration ® Final development during LS 2 13

14 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

15 Resettable fractional divider • Generate h = 64 and h = 8 from h =420 (protons) and h = 423 (ions) • RF VME-based module ® Provides a fractional PLL around 400 MHz (AWAKE) or 30. 5 MHz (PS) ® Frequency reference up to 300 MHz depending on reference divider ratio ® 16 -bit programmable R-divider with reset input for synchronization ® Integrated Phase Shifter (IQ modulator) ® Design made with Altium Designer, improved power supplies S. Rey

16 Resettable fractional divider • Hardware prototype already available ® Preliminary tests on power supplies, FPGA and VME communication successful ® Firmware on-going for preliminary PLL tests S. Rey

17 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

18 20/40/80 MHz • Extension of multi-harmonic feedbacks to cavity controller ® Additional firmware to run on hardware already installed ® Architecture based on 10 MHz cavity controller ® Amplitude and phase control loops ® First tests planned at end of 2018 run F. Bertin

19 20/40/80/200 MHz voltage control surveillance • Additional protection required with new amplitude and phase control loops ® Survey difference of programmed and detected voltage ® Control PIN diodes of 200 MHz cavities ® Single LHC-type VME module for all PS high-frequency systems S. Rey ® Aim at prototype test as proof of concept before LS 2

20 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

21 Digital radial loop receiver Advantages of digital design: • PPM settings (adapt gains on each pickup according to the cycle, slowly switch between low and high-intensity pick-ups) • Stream the radial position digitally out of the boards ® Allows detection of low intensity beams radial position on high-intensity pick-ups N. Pittet

22 Digital radial loop receiver Advantages of digital design: • PPM settings (adapt gains on each pickup according to the cycle, slowly switch between low and high-intensity pick-ups) • Stream the radial position digitally out of the boards DR during low-intensity EAST, ~4∙ 1011 ppp Digital signal processing Analogue processing Transition Signals shifted for display purposes N. Pittet ® Significant increase in dynamic range ® Installation being completed on all pick-ups (in parallel) for beam tests before LS 2

23 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU processing Reference dividers Ref. signal processing RF Beam loops To and from 10/20/40/80/200 MHz RF cavities Beam control overall diagram frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers fbeam, DR fref 2 n frev clocks and SYNC Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

Upgrade of remaining sub-systems • 200 MHz cavity controller ® • Phase pick-up processing and reference phase measurement ® • Modified version of m. TCA-based cavity controller for SPS LLRF PSB beam control motherboard + mezzanines (to be confirmed) Phase, radial and synchronization loop error calculation ® ® Non-synchronous part of the beam control PSB beam control motherboard + commercial mezzanine (to be confirmed) 24

25 10 MHz cavity controller (11) frev 20/40/80 MHz cavity controller (7) open loop 200 MHz cavity controller (6) WCM and DR PUs PU proc. DR PU proc. Df fbeam, DR Reference dividers Ref. signal processing fref RF 2 n frev clocks and SYNC Beam loops To and from 10/20/40/80/200 MHz RF cavities Status summary frev closed loop RF sources for injection trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers Coupled bunch feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

Summary and outlook • Basic design choice of tag-less re-synchronization for beam synchronous sources and receivers ü ü • Validated by 1. 5 years of operational experience with 2 nd generation MHS-based cavity return sum for all beams Ongoing developments ® ® ® Master clock generation and distribution Synchronous fractional divider 20 MHz, 40 MHz and 80 MHz cavity controller Universal voltage control surveillance for all high-frequency cavities Radial offset position detection for radial loop ® Validation checks before LS 2 • Remaining parts most likely based on PSB motherboard and m. TCA cavity controller from SPS 26

27 27 THANK YOU FOR YOUR ATTENTION! H. Damerau, S. Hancock, CERN/GSI Meeting on RF Manipulations and LLRF in Hadron Synchrotrons

28 Spare slides

29 10 MHz cavity MHS (11) controller M HS frev 20/40/80 MHz cavity MHS controller (7) open loop M HS 200 MHz cavity MHS? (6) controller WCM and DR PUs PU processing MHS fbeam, DR Reference dividers Ref. signal processing fref RF 2 n frev clocks and SYNC Beam loops To and from 10/20/40/80/200 MHz RF cavities Simplified overall diagram frev closed loop RF sources for injection MHS trains, etc. PSB, kickers Tomoscope, BSM, BI, etc. Freq. program B, d. B/dt, White Rabbit Master clock 2 n frev clocks and SYNC Synchronous reference dividers Coupled bunch MHS feedback I/Q pair frev, SPS f. RF, SPS Kickers, ref. processing, RF cavities Finemet cavity Other digital signals

2 nd generation MHS system • Multi-harmonic sources exchanged during EYETS 16/17 h, f, F, t frev closed loop (beam control) Master DDS h=256 MHS driving 10 MHz cavities integrated in cavity controller • Separate MHS to generate beam control signals ® Commissioned: 2017 start-up • RF to cavity 11 MHS … RF to cavity 96 3 MHS h = 1, 4/8, 8 to PSB 2 MHS TREV/TRF distribution 2 MHS Simulated cavity return Drive to 20/40/80 MHz 2 MHS h = 9/13 for ions • • Coupled-bunch feedback Cavity return sum 30

Beam control upgrades with MHS • Important simplification of beam controls • ® ® • • Suppressed injection synchronization (10/2016 ) Signals for synchronization with PSB directly derived from MHS system Injection phase/bucket controlled by function for all beams (both inj. ) Relative phase control by functions for all beams Suppression of dedicated hardware doing phase jumps for bunch rotations and transition crossing feed-forward With feedforward to cavities 10. 5 ms Distributed frev moves with bunch t [ns] 31

Beam control upgrades with MHS • Important simplification of beam controls • ® • • • Suppressed injection synchronization (10/2016 ) Signals for synchronization with PSB directly derived from MHS system Injection phase/bucket controlled by function for all beams (both inj. ) Relative phase control by functions for all beams Suppression of dedicated hardware doing phase jumps for bunch rotations and transition crossing feed-forward EAST double bunch rotation With feedforward to cavities 32

Beam control upgrades with MHS • Important simplification of beam controls • ® • • • Suppressed injection synchronization (10/2016 ) Signals for synchronization with PSB directly derived from MHS system Injection phase/bucket controlled by function for all beams (both inj. ) Relative phase control by functions for all beams Suppression of dedicated hardware doing phase jumps for bunch rotations and transition crossing feed-forward Ion acceleration, frev sweep Compensated azimuth for frev 33

CURRENT SYSTEM • AVC (Automatic Voltage Control) module is used to control the 200 MHz cavities voltage • AVC Surveillance checks various signals and control a RF switch and PIN diods • Unique NIM hardware module both for AVC loop and AVC Surveillance, separate NIM module for the RF switch 10. 7 MHz IF from cavities 200 MHz from SPS PS Cavity AVC Surveillance Upgrade – September 4 th, 2018 200 MHz RF to 25 k. W amplifier 34/4

SIGNALS SYNTHESIS type Input / Output 20 MHz 40 MHz 80 MHz RF on Digital In ? ? ? RF off Digital In ? ? ? Prog In (serial) Serial In FWD Cavity return RF In RFL Cavity return RF Input ? ? ? Level 2 ready Digital In Pin Diod start Digital (trigger) In RF switch In detect. RF Input RF switch Out detect. RF Input Pin Diod out Digital Out Alarm out Digital Out Water level Digital Input PS Cavity AVC Surveillance Upgrade – September 4 th, 2018 200 MHz 35/4