SP3 Timing System - SLAC

SPEAR 3 Timing SystemR. Hettel Injection timing intervals and sequence Injection and ejection energy windows Timing system configuration SPEAR 3 and Booster RF frequency choices RF signal and clock frequencies RF stability and resolution requirements Master oscillator Booster RF Generator and Timing Modulator Bucket select using I/Q modulation of RF Injection rate reductionR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR septumand kicker K2kicker K1B130SPEAR 3 Injectorinjection septumand kickerejectionseptumCBoo 4/7 CSP3ejectionkickerchopperRFR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 Injection Timing Intervals Time interval between Chopper and Booster RF cavity is fixed:T(Chop-BOOrf) adjusted using analog vernier input to Coincidence/Vernier Time interval between Booster RF cavity and 1st SPEAR RF cavity is fixed:T(BOOrf-SPrf) adjusted using SPEAR RF phase control (LLRF) Time interval in Booster (measured at RF cavity) M x TBOOrev, M integerBooster bucket will be aligned with SPEAR target bucket every 7 Boosterrevolutions 4 SPEAR revolutions Time interval in Booster can be delayed or advanced by an integer number of SPEARRF bucket periods using I/Q modulation of Booster RF Injection and ejection energy windows can be detected and used to gate RF-sync'dtriggersR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 Injection Timing SequenceSequence of events needed to inject beam into a given SPEAR bucket: Detect first SPEAR revolution timing fiducial occurring within injection energywindowtiming fiducial repeats at fSPrev; TSPrev 280 TBOOrf proper timing to hit Booster RF bucket is maintained Trigger Linac klystron modulator and S-band drive amplifier 2 µs macropulse width; 100 ns timing accuracy Trigger Booster Injection Kicker 0.8 µs width; 10 ns timing accuracy Trigger Linac beam Chopper to permit 3-5 S-band microbunches to enter Linacand Booster 200 ps timing accuracy with respect to Booster RF cycle The above three triggers must occur within a Booster injection energy windowof 0.1% for effective beam capture 112 MeV 0.1%R. HettelSPEAR 3 Timing SystemSept. 18, 2003

Booster Injection Timing Acceptance0.6 ns0.6 nsTime accep tan ce det er min ed by momentum accep tan ce :bunch momentum oscillatio ns caused by t b time of arrivalwrt to synchronou s phase : p 2 πν s f rev t b pα1/ 2 α h cos( ϕs ) eVgap ν s synchrotro n tune 2 πE b 1 1ϕs synchronou s phase sin (q ) 150 o at injectionν s 0.016 at injection ; ν s f rev 35 kHzRF momentum accep tan ce in ramping booster :RF Buckettiming acceptance1S-band microbunchesafter chopper 0.6 0.6nsϕ s 150o0.80.6Vgap/Vgap(max)ns1/ 2 2( U E b E b ) p( q 2 1 cos 1 (q 1 )) p πα hE b C γ E 4b (GeV 4 )U E b (GeV ) radiated energy loss / turn ρ( m )0.40.20-0.20100200-0.4-0.6300400C γ 88 .6 x 10 63( m / GeV ), ρ dipole bend radius 12 m E b energy change / turn from ramp -0.8-1phase (degrees)q 1 dE bTrevdtU E b E beVgapα momentum compaction factor 0.033h harmonic number 160 pFor booster , 0.4% at injectionpR. Hettelocan accept t b 0.6 ns ( ϕSept.752003)b 18,SPEAR 3 Timing System

SPEAR 3 Injection Timing Sequence - cont. Delay or advance the timing of bunch in Booster during acceleration so thatproper SPEAR bucket will be filled Trigger Booster Ejection Septum supply 15 ms before beam extraction Trigger Booster Ejection Kicker and SPEAR Injection kickers after acceleratingbeam in Booster for 36 ms, during a Booster revolution when the bunch istemporally aligned with the target SPEAR bucket 0.8 µs width; 10 ns timing accuracy The above kicker triggers must occur within a Booster ejection energy windowof 0.1% for effective SPEAR beam capture3 GeV 0.1%R. HettelSPEAR 3 Timing SystemSept. 18, 2003

Kicker Timinginjected beamto Boosterejected beamfrom Boosterinjected beamto SPEARTBOOrev 446 nsTBOOrev 446 nsTSPrev 781 ns 450nsR. Hettelglitch 450nsSPEAR 3 Timing System 750 nsSept. 18, 2003

Injection/Ejection Timing and 10 Hz White CircuittBej 44.5 ms600Imax 645 A625 A ejectionWhite Circuit:500400I (amps)I IDC - IACcosω0t485 A pkejectionseptumcurrentω0 2 π x 10 HzFor 3 GeV:IDC 310 AIAC 335 A300200100tBinj 8.65 ms25 Ainjection01001020Imin -25 A30405060708090100time (ms)White Circuit magnet and pulsed Ejection Septum current waveforms for112 MeV injection and 3 GeV ejection.R. HettelSPEAR 3 Timing SystemSept. 18, 2003

Maximum Ejection Timing Windowt Bej 49.01 ms0.41 ms626t 50 ms0.99 ms1.40 ms625 A 0.1%625 A ejection625625 A - 0.1%I (amps)6242.80 ms623White Circuit CurrentI I DC- IACcosωot622ωo 2π x 10 HzIDC 300.313 A621IAC 325.313 A62047484950515253time (ms)Ejection energy window is maximized when peak White Circuit current is set 0.1% higherthan ejection current. Current stability must be a small fraction of 0.1%.R. HettelSPEAR 3 Timing SystemSept. 18, 2003

White Circuit Injection/Ejection Timing WindowsInjection energy window: E/E IWC/IWC 0.1% tBinj 2.5 µs( 3 SPEAR revs) IBinj 0.1% x 25 A 0.006% Imax need peaking strip to detect tBinjEjection energy window: E/E IWC/IWC 0.1% tBej 88 µs( 115 SPEAR revs) IBej 0.1% x 625 A could dead-reckon to tBinj if have 0.1% power supplies,but use WC current transductor (Danfysik) to detect IBejR. HettelSPEAR 3 Timing SystemSept. 18, 2003

Injection and Ejection Timing TriggersTSPrev 781 ns E/E @ 112 MeV ection Timinginjectiontrigger4 x TSPrev 7 x TBOOrev 3.12 µs E/E @ 3 GeV 0.0036%Injection tiontriggerR. HettelSPEAR 3 Timing SystemSept. 18, 2003

White Circuit Current Regulation and Timing1000100Booster current (A)tBej 44.5 ms10tBinj 8.8 ms10102030405060708090100time (ms)0.1 I/I 0.1% I/I in %0.01White Circuit current stability as a function of time in a 10 Hz cycle, assumingthe DC and AC power supplies each have 0.1% stability. The ejection currentstability is 0.1% at tBej, implying the ejection time can be dead-reckoned.R. HettelSPEAR 3 Timing SystemSept. 18, 2003

Injection Energy Gate - Peaking Strip Processordipolefieldpermalloymagnetizationcoil biascurrent sourceinjectionenergy adjI biasbiasfieldBbias(DAC)permalloy stripsin bias coilinjectionenergy gate 90 mV(2100 turns)pulse processordipolefieldB(3 GeV) 8.35 kGB(112 MeV) 0.31 kGBWC 4.14 - 4.48 cos(20πt) kGWhite Circuit Injection Energy Detection100current (amps)(150-turn coil)dB/dt (112 MeV, t 8.65 ms) 3.8 kG/s7550IWC 23.3 AE 112 MeV25Bbias 0.31 kG0-15-10-50time (ms)510-25K. Endo, H. SasakiINS TokyoSJC-A-70-5, 1970R. Hettelpeaking strippulseSPEAR 3 Timing SystemSept. 18, 200315

10 Hz Clock and Energy Gate Timing System60 Hz10 Hz uitPulserTrackingSupplies RF rampinjectionthresholdMagnetCurrentR. HettelDCCT(Danfysik)TriggerDelay(SRS rator)SPEAR 3 Timing SystemTriggersControllerinjection gateejection gateSept. 18, 2003

SPEAR 2 RF-Synchronized Timing SystemR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 RF-Synchronized Timing SystemSPEARLLRFBucket trigTimingController476.3 MHzto SPEARklystronI13 kHz476.3 MHzRF/ClkSig Gen(Wenzel)TrigDelaybucket select(VME Dig Out)(SRS 535)Boo RF Gen/Timing ModClk/SyncDistrib358.5 MHzto Booster RFtrigCoinc/Verniergatedelay inMasterOscS-band ampmodulatorinjection kickerTrigDelay(SRS 535)chopperrate control (GPIB)10 Hz inject triggertrig. 1602.24 MHz (fBOOrev)clk10 Hz eject triggerTrigDelayout 1RF in358.5MHz. (160 x 7)Sync/Divide10 Hz ejectenergy gateR. HettelTrigDelayvernier delay(CAMAC DAC)(PTS-500)freqcontrol(GPIB)10 Hz camera trigclk1.28 MHz10 Hz injectenergy gate476.3 MHz10 Hz BPM trigQ13 kHz(SRS 535)1.28 MHzfSPrevSpiricon trig(SRS 535)clktrigDataSyncgateeject kicker 1eject kicker 2out 2Trig DelayUnitinject enablefrom orbit interlockInjectControlPanelSPEAR 3 Timing SystemTrigDelay(2 eaSRS 535)SPEAR kicker 1SPEAR kicker 2SPEAR kicker 3Sept. 18, 2003

SPEAR 3 Kicker Trigger Enable/Disable 5Venabledisable 5V74F507474F3037externalkickertrig enab(J2)kickertrigger in(J1)R. HettelDQQ5074F3037SPEAR 3 Timing Systemkickertrigger out(J3)Sept. 18, 2003

SPEAR 3 and Booster RF Frequency ChoicesTable 1. Harmonic number, rf frequency and circumference options for SPEAR and theBooster assuming the use of either SPEAR 2 ( 358.5 MHz) or PEP -II ( 476 MHz) rf cavities.SPEARBoosterhfactors of hfrf (MHz)C (m)constraints28023 · 5 · 7358.53 - 358.60234.08 - 234.15SPEAR circumf. limita3717 · 53475.00 - 475.15234.08 - 234.15SPEAR circumf. limit37222 · 3 · 31476.28 - 476.43234.08 - 234.15SPEAR circumf. limit16025 · 5358.48 - 358.60133.76 - 133.80cavity freq. limitb21222 · 53475.00 - 475.35133.70 - 133.80Booster circumf. limitc;cavity freq. limitd21222 · 53476.33 - 476.43133.40 - 133.43Extended Booster circumf.limite; same freq as h 372SPEAR2133 · 71476.89 - 477.00133.87 - 133.90Booster circumf. limit;cavity freq. limitd2133 · 71476.33 - 476.43134.03 - 134.06Extended Booster circumf.limite; same freq as h 372SPEARhSP3 372 2 · 2 · 3 · 31C hc/ fRF9 symmetric fill patterns:CSP3 234.1421 m frfSP3 476.3 MHz2-, 4-, 6-, 12-, 31-, 62-, 93-, 124- and 186-bunchhBoo 372 2 · 2 · 2 · 2 · 2 · 5R. HettelCBoo 4/7 CSP3 133.7955 m frfBoo 358.505 MHzfrfBoo/frfSP3 70/93SPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 RF Signal and Clock FrequenciesSPEAR RF:fSPrf 372 x fSPrev 476.300 MHzSPEAR revolution freq:fSPrev 1.2804 MHzBooster RF:fBrf 160 x fBOOrev 70/93 x fSPrf 358.505 MHzBooster revolution freq:fBOOrev 7/4 x fSPrev 2.2407 MHzBPM LO:fLO 359 x fSPrev 459.655 MHzBPM IF:fIF 13 x fSPrev 16.645 MHzIF digitizing clock:fIFclk 50 x fSPrev 64.019 MHzStreak camera clock:fSC fSPrf/4 93 x fSPrev 119.075 MHzR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 RF Clock/Signal GeneratorSPEAR RF:BPM LO:fLO 359 x fSPrev 459.655 MHzSPEAR revolution freq: fSPrev 1.2804 MHzBPM IF:fIF 13 x fSPrev 16.645 MHzBooster RF:fBrf 160 x fBooRev 358.505 MHzIF digitizing clock:fIFclk 50 x fSPrev 64.019 MHzBooster rev freq:fBooRev 7/4 x fSPrev 2.2407 MHzStreak camera clock: fSC fSPrf/4 93 x fSPrev 119.075 MHzR. HettelfSPrf 372 x fSPrev 476.300 MHz(Wenzel)SPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 RF Clock/Signal Generator(Wenzel)rear panelR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 RF Stability and Resolution Requirements fRF causes change in path length and horizontal beam position in dispersionregions (e.g. dipole source points): x ηx f RF 0.01 σ x 1.6 µm for dipole sourceα f RFα 0.00113 ηx 0.1 m f RF 1.8 x 10 8f RF f RF 9 Hz Phase noise:φ max h f RF 0.06 oν s f RFν s synchrotron tune 0.007 for SPEAR 3 fRF causes beam energy shift; to maintain 10-4 - 10-5 undulator photonenergy stability: E1 f RF f 5 x 10 5 to 5 x 10 6 RF 5 x 10 8 to 5 x 10 9Eα f RFf RF f RF 2 20 HzR. Hettel φ max 0.01o 0.1oSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 Master OscillatorPTS 500 Stability: 3x10-9/day, 10-6/yr, 10-8/0-50oC 1-500 MHz, DDS-basedneed 476.3 MHz 50 kHz 0.057o integrated phase noise, 0.5 Hz-15 kHz 0.2 Hz step resolution GPIB control Phase-continuous frequency switchingR. HettelSPEAR 3 Timing SystemSept. 18, 2003

Integrated phase noiseSSB spectral density (L(f))degreesdBc/Hzfreq (Hz)freq (Hz)φ 2 2L(f )dfR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 Booster RF Generator and Timing ModulatorfrfBoo/frfSP3 70/93 frfBoo 358.505 MHzR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 Booster RF Generator and Timing ModulatorR. HettelSPEAR 3 Timing SystemSept. 18, 2003

SPEAR 3 Booster RF Generator and Timing ModulatorR. HettelSPEAR 3 Timing SystemSept. 18, 2003

Injection Timing with I/Q Modulation of RFcosφm(t)Q incos(ωRFt)cos(ωRFt φm(t) ) 90oI inmodulating phase shift:sinφm(t)6πN 3φ(t)00N -3-6π0Iφm(t) ωmdt 2πNN number of modulatingwaveform cycles bucket number(N -185 to 186)fm ωm/ 2π 13 kHzQR. HettelSPEAR 3 Timing SystemSept. 18, 2003

Booster RF Phase Shift TimingtBej 44.5 ms600start phase shift@ 43 ms - N x 0.0769 msend phase reset@ 77 ms500I (amps)40014.3 msmax14.3 msmaxend phaseshift @ 43 ms300200start phase reset@ 77ms - N x 0.0769 mstBinj 8.65 ms1000102030100405060708090100time (ms)I/Q control frequency 13 kHzI/Q control period 0.0769 mstime for max phase shift of 186 buckets 186 x 0.0769 ms 14.3 msR. HettelSPEAR 3 Timing SystemSept. 18, 2003