1. Chopper wheel Rotates at 100 Hz and contains a timing photodiode to signal position on each turn. A slot cut in the disc passes a 130  s laser pulse train every turn. Stanford DG535 (Repetition Rate) This unit sets the macropulse repetition rate by inhibiting the 100 Hz timing signal from the chopper wheel Quantum Composer 8-Channel timing unit This unit is triggered by the Repetition Rate DG535, and takes a clock input from the 81.25 MHz RF reference. On triggering, it waits for the next RF clock cycle, then cascades trigger signals to the Mechanical Shutter (selecting a specific macropulse), and to the Macropulse Length DG535 to set the macropulse length. Additional trigger signals are provided to the rack room and the TW laser. Mechanical Shutter The mechanical shutter selects specific macropulses from the 100 Hz macropulse train to define the 1, 2, 5, 10 or 20 Hz repetition rate Stanford DG535 (Macropulse Length) This unit provides trigger to the Pockels cell driver to define the macropulse length AΠBAΠB

2. Quantum Composers Timing Unit Settings Sync.ChannelWidthDelayPolOutputMode Wait PulsesDriving Alternative for ‘other’ chopper sensor location T0T0 'A'140 us0 msAct highTTL/CMOSNormal0Main RF trigger (via #1 on roof feed-thru box) ‘A’'B'4 ms24.8 msAct highTTL/CMOSNormal0Mechanical chopper4.5 ms / 4.0 ms T0T0 'C'Act highTTL/CMOSNormal0Not used (suspected faulty) T0T0 'D'15 us27.674 msAct highTTL/CMOSNormal0Trigger to DG535 7.085 ms / 150  s T0T0 'E'100 us20 msAct highTTL/CMOSNormal0Feed to rack room (via #7 on roof feed-thru box) T0T0 'F'Act highTTL/CMOSNormal0 T0T0 'G'Act highTTL/CMOSNormal0Streak Camera trigger T0T0 'H'Act highTTL/CMOSNormal0Macropulse repetition rate Gate: Mode (Chan Menu) – Source Ext. w/PLL; Level - 2.50 V; Rate - 81.25 MHz; Level - 0.1 V; Ref. out - To pulse; Ext. Opt. - Force OFF; T 0 clock rate - 0.010000000 Trig: Mode – Triggered; Level – 1.00 V; Edge – Rising Edge

3. DG535 Unit Settings: Macro Pulse Repetition Rate ChannelDelayDriving ‘EXT’ 'A'A = T + 0 'B'B = T + 0.001 150 500Quantum Composers Master Timing Unit 'C'C = T + 0.092ms delay, specify 10 Hz repetition rate 'D'D = C + 0Trigger to DG535 ‘A-B'14 usA-B Signal triggers Quantum Composers unit at macropulse repetition rate This setup is no longer valid as the QC9530 is providing a timing-inhibit function to set the macropulse repetition rate

4. DG535 Unit Settings: Macro Pulse Length (Pockels Cell) ChannelDelayDriving 'A'A = T + 0.000 290 010Trigger onset delay 'B'B = A + 0.000 000 010Macro Pulse length (example shows 10 ns) 'C'C = T + 0 'D'D = T + 0.000 200Trigger to rack room feedthrough #3 for the BPM system T0T0 Trigger to rack room feedthrough #4 Trig: Ext.; Threshold = +0.16 V; Slope (+/-) = +; Trigger term = High Z Output: AB; AB & -AB Loads = High Z; AB: TTL