renovation of the 200 MHz RF system LLRF issues

Cavities redistribution 26 October th LIU-SPS Coordination Meeting 2  2011 : 4 cavities 2 x 4 sections 2 x 5 sections + 3 spare sections  2018 : 6 cavities 4 x 3 sections 2 x 4 sections + 1 spare section Courtesy of Elena Shaposhnikova

1.7 MW amplifier, i.e 1.4 MW cavity 26 October th LIU-SPS Coordination Meeting 3  To have 1.4 MW available at the cavity input, 1.7 MW at the Final output are needed  A major improvement to present systems would be to have individual SSA drivers per PA  Taking advantage of the long experience we have with tetrodes and combiners, the solution will be 16 x PAs combined through 3 dB combiners  Four contracts :  Drivers (SSA)  Finals (SSA or Tetrodes)  Combiners (3 dB above 100 kW)  Transmission lines (coaxial, 345 mm outer) Drivers 16 SSA Final 16 PAs 3 dB combiners and power loads 120 m and 180 m Coaxial lines To cavity input 120 m away From Beam Control 1/16 splitter 1.7 MW -0.6 dB total 1.5 MW -0.2 dB 1.4 MW

16 Tetrodes vs 2048 SSA 26 October th LIU-SPS Coordination Meeting 4  Tetrodes tube costs over 20 years will be added :  20 years * 3/4 * 335 * 24 * 16 * 2 = 3’859’200 total hours  With 20’000 hours per tube = ~ 200 tubes  SSA :  + 20% to 25% additional transistors (not module)  Individual circulators are mandatory  Wall plug efficiency will be part of the adjudication  HVPS included (Tetrodes)  Losses in all SSA combiners, circulators and loads included 1.7 MW 128 x 830 W SSA FinalTetrodes (gain = 12 dB) SSA (Gain = 20 dB) Nominal ratings 16 x 106 kW = 1700 kW2048 x 830 W = 1700 kW Maximum ratings For 1400 kW at cavity input Maximum 2 faulty tubes 14 x 138 kW = 1932 kW Maximum 48 faulty modules 2000 x 891 W = 1782 kW Maximum ratings Driver 16 x 8.7 kW16 x 1.1 kW 16 x 106 kW Tetrodes 16 x

First upgrade: Present amplifiers 26 October th LIU-SPS Coordination Meeting 5 Maximum RatingsPresentFuture CW, 5 seconds650 kW700kW Pulsed, 43 kHz900 kW1100 kW Tubes per year (547’000 CHF) (629’000 CHF) Solutions Increased Filament voltageVery expensive Siemens HVPSneed a full re-cabling and an air cooling improvement Philips amplifiersair cooling plant to be modified BW -3dB Compromise to be discussed with LLRF

More Power with Present amplifiers 26 October th LIU-SPS Coordination Meeting 6  Increase filament voltages :  Very expensive (562’000 CHF -> 1’111’000 CHF per year)  Effective efficiency not tested !  Additional down time YL1530 Ufil Max peak power LifetimeTube per year Nb of stopsYL1530 Costs Additional cost Nominal900 KW25’000 hrs17 187’ %1.0 MW- 25 % ’ ’ %1.1 MW- 44 % ’ ’000 RS2004 Ufil Max peak power LifetimeTube per year Nb of stopsRS2004 Costs Additional cost Nominal800 KW20’000 hrs ’ %900 kW- 25 % ’ ’ %1 MW- 44 % ’ ’ %1.1 MW- 58 % ’ ’000

More Power with Present amplifiers 26 October th LIU-SPS Coordination Meeting 7  HVPS Siemens improvements :  Full re-cabling  Air cooling modification  Philips amplifiers improvement :  Air cooling modification  ‘pre-modifications’ during next Xmas stop to test new configuration during a MD in 2012 :  TX3 Siemens HVPS  TX5 Air cooling Siemens HVPS need an air cooling improvement Siemens HVPS need a full re- cabling with new cable spacers

More Power with Present amplifiers 26 October th LIU-SPS Coordination Meeting 8  Driver over coupled trick already used nowadays on all TXs  Maximum Power strongly proportional to BW  Driver over coupled trick already used nowadays on all TXs BW -3dB [MHz] Pout [kW]

Present amplifiers BW 26 October th LIU-SPS Coordination Meeting 9  The effective BW of the 1-Turn feedback is limited by  The TX gain BW: When the TX gain drops by ~ 20 dB, the overall loop has no more gain  The TX phase non-linearity: When the phase shift exceeds +-50 degree the overall loop gain must have dropped by more than 20 dB to keep the system stable  Conclusion: Good correction only in the band limited by +-30 deg phase non-linearity, and with an effectiveness that drops as the TX gain BW BW -3dB BW -15dB Phase distortion Siemens Line 1TX1 + TX24 sections ≥ 2.5 MHz ≥ 5 MHz+/- 3.0 MHz+/- 30 ° Line 2TX3 + TX44 sections Philips Line 3TX5 + TX65 sections ≥ 8 MHz+/- 5.0 MHz+/- 30 ° Line 4TX7 + TX85 sections

BW specifications ? 26 October th LIU-SPS Coordination Meeting 10  New plan :  Present amplifiers connected to 3 sections cavities with higher bandwidth than 4 and 5 sections as per nowadays  New amplifiers connected to 5 sections cavities  What is the acceptable BW limit ? :  For ‘Siemens’ and ‘Philips’  For new amplifiers  2018 : 6 cavities 4 x 3 sections 2 x 4 sections + 1 spare section

Operation modes (on a match power load) 26 October th LIU-SPS Coordination Meeting 11 Measurements to be made on a power load Measurements with a MHz carrier at 400 kW and a frequency sweep 20dB below carrier : Non linear phase distortion at +/- a MHz: max. +/- b° Passband at -1 dB: x.0 MHz Passband at -3 dB: y.0 MHz Passband at -15 dB: z.0 MHz Measurements to be made in CW and 10 us/43 kHz on a power load With Po = 850 kW cw With Po = 1700 kW 10 us / 43 kHz Pout vs Pin must be monotonic from zero to Po Small signal differential gain g = dPout/dPin, in the range 0.1 Po to 0.9 Po : Local slope variation max +/-15% Can vary by 3 dB maximum. Gain saturation curve Non linear phase distortion (CW): Δ φ max < 10º Non linear phase distortion curve

Operation modes (on a match power load) 26 October th LIU-SPS Coordination Meeting 12 Continuous operation 24/24 hours CW for 10 months continuously Very Long Pulses operation Fc = MHz +/- 0.5 MHz : 100% from 0 to 900 kW with rise and fall time < 0.5 µs 5 seconds ON / 5 seconds OFF AM modulation #1 Fc = MHz +/- 0.5 MHz : 100% from 0 to 900 kW with rise and fall time < 0.5 µs Repetition time 10 µs (100kHz) AM modulation #2 Fc = MHz +/- 0.5 MHz : 0 to 1700 kW with 4 MHz triangle AM 25 % in power Rise and fall time < 0.5 µs Flat top pulse and off pulse length of 11 us Repetition time 23 µs (43kHz) (and 172 kHz) This cycle for 20 second then 1 second OFF.

New RF building 26 October th LIU-SPS Coordination Meeting 13  No more ‘Power’ in BB3 Faraday Cage  Specific ‘Power’ control room in new RF building, Cavity controllers, Conditioning systems, amplifiers monitoring  BB3-FC large enough for 6 systems ?

Beam Control resources Beam Control 1’ Draft schedule 26 October th LIU-SPS Coordination Meeting 14 Authorizations Install Build new hardware Year 4Year 3Year 2Year 1Year 5 Building Services RF : Building: Year 6Year 7 Commissioning Tunnel : Build New hardware Installation phase 1 (pickups + dampers + EL + coax lines …) Installation phase 2 (cavities + pickups + CV + EL + vacuum) Cavities re-arrangement within a LS ( > 6 months) Studies (amplifiers, couplers, cavities, LLRF) Tendering (s) Studies Services

LLRF/Beam Control open issues ? 26 October th LIU-SPS Coordination Meeting 15  What is the acceptable lower BW limit ? :  For ‘Siemens’ and ‘Philips’  For new amplifiers  Technical Specifications ?  BB3-FC large enough for 6 systems ?  Is a 3 sections cavity available in new RF building earlier useful ?  Is the draft schedule still correct ?  Time table  Resources  Money  How many time for commissioning without/with beam ?  What if LS2 earlier ? (later ?)  What else ?