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 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

Quantum Composers Timing Unit Settings Sync.ChannelWidthDelayPolOutputMode Wait PulsesDriving Alternative for ‘other’ chopper sensor location T0T0 'A'100 us0 msAct highTTL/CMOSNormal0Main RF trigger (via #1 on roof feed-thru box) ‘A’'B'4 ms24. msAct highTTL/CMOSNormal0Mechanical shutter4.5 ms / 4.0 ms T0T0 'C'150 us0Act highTTL/CMOSNormal0Not used (suspected faulty) T0T0 'D'150 us7.06 msAct highTTL/CMOSNormal0Trigger to DG ms / 150  s T0T0 'E'100 us7.00 msAct highTTL/CMOSNormal0Feed to rack room (via #7 on roof feed-thru box) T0T0 'F'100 us7.06 msAct highTTL/CMOSNormal0EMMA RF System Trigger T0T0 'G'100 us msAct highTTL/CMOSNormal0Streak Camera trigger T0T0 'H'91 ms1.1 msAct highTTL/CMOSNormal0Macropulse repetition rate (setting for 10 Hz) Gate: Mode (Chan Menu) –Level V; Clock:Rate MHz; Level V; Ref. out - To pulse; Ext. Opt. - Force OFF; T 0 clock rate Trig: Mode – Triggered; Level – 1.00 V; Edge – Rising Edge Incorrect timing settings which do not drive EMMA RF correctly due to a 20 ms offset in the main R trigger, changed

Quantum Composers Timing Unit Settings Sync.ChannelWidthDelayPolOutputMode Wait PulsesDriving Alternative for ‘other’ chopper sensor location T0T0 'A'140 us20.31 ms Act highTTL/CMOSNormal0Main RF trigger (via #1 on roof feed-thru box) ‘A’'B'4 ms24.0 ms Act highTTL/CMOSNormal0Mechanical shutter4.5 ms / 4.0 ms T0T0 'C'150 us0 Act highTTL/CMOSNormal0Not used (suspected faulty) T0T0 'D'150 us26.37 ms * Act highTTL/CMOSNormal0Trigger to DG ms / 150  s T0T0 'E'100 us26.41 ms ** Act highTTL/CMOSNormal0Feed to rack room (via #7 on roof feed-thru box) T0T0 'F'100 us7.01 ms Act highTTL/CMOSNormal0EMMA RF System Trigger T0T0 'G'100 us ms Act highTTL/CMOSNormal0Streak Camera trigger T0T0 'H'95 ms1.1 ms Act highTTL/CMOSNormal0Macropulse repetition rate (setting for 10 Hz) Gate: Mode (Chan Menu) – Level V Clock:Source Ext. w/PLL; Rate MHz; Level V; Ref. out - To pulse; Ext. Opt. - Force OFF; T 0 clock rate Trig: Mode – Triggered; Level – 1.00 V; Edge – Rising Edge * = Value changed from ms to ms on May 23 following shutdown work. ** = Value changed from ms to ms (noted on 28/8/12 – not sure when change was actually made) New timing settings established to drive EMMA RF correctly using timing sensor located on the left-hand side of the chopper wheel, set

DG535 Unit Settings: Macro Pulse Repetition Rate ChannelDelayDriving ‘EXT’ 'A'A = T + 0 'B'B = T Quantum Composers Master Timing Unit 'C'C = T ms 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

DG535 Unit Settings: Macro Pulse Length (Pockels Cell) ChannelDelayDriving 'A'A = T Trigger onset delay 'B'B = A Macro Pulse length (example shows 10 ns) 'C'C = A – 'D'D = C Trigger to Pulse picker Pockels cell T0T0 Trigger to PC for PCO camera or streak camera Trig: Ext.; Threshold = V; Slope (+/-) = +; Trigger term = High Z Output: AB; AB & -AB Loads = High Z; AB: TTL Values correct, as of October 25 th Channel ‘A’ adjusted slightly to capture beam following shutdown work