Pulsed Magnets - SR Kicker Current Waveform 6 s 2.5kA 4 kicker - PowerPoint PPT Presentation

“Top-up” Operation at the Swiss Light Source Pulsed Magnets - SR Kicker Current Waveform 6 µ s 2.5kA 4 kicker pulses SPring-8 12/03/02 Michael B¨ oge 21

“Top-up” Operation at the Swiss Light Source Pulsed Magnets - SR Kicker Field Measurements SPring-8 12/03/02 Michael B¨ oge 22

“Top-up” Operation at the Swiss Light Source Digital Power Supplies - Overview One Digital Control Unit for ~600 power supplies of the SLS Short/Long-Term: <10/30 ppm Short/Long Term: 1/30 ppm SPring-8 12/03/02 Michael B¨ oge 23

“Top-up” Operation at the Swiss Light Source Digital Power Supplies - 1 MVA Bending Booster SPring-8 12/03/02 Michael B¨ oge 24

“Top-up” Operation at the Swiss Light Source Timing System - Structure SPring-8 12/03/02 Michael B¨ oge 25

“Top-up” Operation at the Swiss Light Source Timing System - Basic Logic for Top-up • Inject every Nth cycle when the current is below a defined threshold – Gun trigger, SR injection kickers trigger enabled when a top-up cycle occurs – Possibly switch off booster cycle (not tried yet) – Warn beamlines, send a gate event to disable DAQ. – Need to synchronize several IOCs • Synchronously count cycles to determine when to trigger • Cycle data preset through channel access, synchronized with an event SPring-8 12/03/02 Michael B¨ oge 26

“Top-up” Operation at the Swiss Light Source Digital BPM System - Overview Only One BPM System PSI + in Different Operation Mode for All Machines Turn−by−Turn: 1 MSample/s, <20 mu m Closed Orbit: 4 KSample/s, <1.2 mu m Turn−by−Turn: Vital for Commissioning Closed Orbit Mode −> Fast GlobalOrbit Feedback SPring-8 12/03/02 Michael B¨ oge 27

“Top-up” Operation at the Swiss Light Source Top-up Operation - Current Stabilization ICT1=0.62 nC ICT2=0.58 nC • LTB:ICT2=0.58 nC ICT3=0.35 nC • LTB:ICT3=0.35 nC (60 %) = 0.60 * ICT2 • BS:MPCT=0.1 mA 10 min 3.5 sec • SR:PCT=300-301 mA Lifetime • SR: τ =10 h 10 h 301 mA • SR:dPCT=0.3 mA/sec 1 mA Current 300 mA 2 min @ 10 h • SR: dt =3.5 sec (1 mA) 0.3 mA/sec Injection Rate ~20 mA/min SPring-8 12/03/02 Michael B¨ oge 28

“Top-up” Operation at the Swiss Light Source Top-up Operation - Long Term Current Stabilization • 2 days run @ 250 mA with a deadband of 1 mA in October • τ =12 h @ I=250 mA (I × τ =3 Ah) • time between injections dt =3 min ( ≈ 960 injections in 48 h) SPring-8 12/03/02 Michael B¨ oge 29

“Top-up” Operation at the Swiss Light Source Top-up Operation - Bunch Pattern Phase 15 deg Standard Mode: • I=300 mA Current +0.1mA +13% • 45+390+45=480 buckets 0.77 mA • I s =0.77 mA ± 0.1 mA −13% −0.1mA • I Variation ± 13 % 390 x 0.77=300 mA • φ =15 deg over train 45 45 buckets buckets 780 nsec Bucket #0 Bucket #389 SPring-8 12/03/02 Michael B¨ oge 30