Set up timing delay for new designed nozzle

In order to synchronize the old small nozzle with laser pulses, I have added about 1 millisecond delay between the laser seed pulses and the final laser pulses. However, this delay is not enough for the new big slit nozzle, which needs at least 3 or 4 milliseconds to be operated. So I think it's better to trigger the nozzle with the first laser pulse and fire with the second laser pulse. Because the Prometheus runs at 0.2 Hz, there is 5 seconds delay between two continuous pulses. It's free to tune the delay time during this 5 seconds, the main point is how to synchronize the gas nozzle with the second laser pulse. A digital delay box was used, this box can provide the timing delay from seconds order to microsecond order. After several trials, the delay was set up at about 4 s 913 ms.