The triggers for the laser are sourced from EVR:LA20:LS21. The "Event Receiver" (EVR) receives timing information from an "Event Generator" (EVG) that lives in S10. This pages describes how the laser is synchronized to the triggers that are produced by the EVR. This is necessary because the laser itself contains other timing hardware, like the SDG for the regen and the DG645s that control the SAGAs and CCR CFR pump lasers. Because of this timing hardware downstream of the EVR, as well has all the glass of various indexes of refraction that can delay the laser, the regen laser pulses themselves must be compared to a reference trigger to determine when in time the laser leaves the regen.
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