At LANL they put many experiments/sensors in the bomb stack. A group I was with ran an experiment called PINEX (Pinhole Imaging Neutron Experiment), they used

At LANL they put many experiments/sensors in the bomb stack. A group I was with ran an experiment called PINEX (Pinhole Imaging Neutron Experiment), they used high speed video cameras to capture light/photons from a light intensifier. A meter diameter lead sphere was placed between the bomb and the light intensifier to attenuate the neutron signal. The length of the video cable (coax) was measured in time units. They could get about a frame and half of video off the CCD and out of the bomb hole before everything was vaporized. The video was captured using analog-to-digital signal converters and then interpreted later. The ADC, memory, pulse generators (to trigger light intensifier, start the CCD sweep, etc.) were sitting in a CAMAC crate attached to a customized VAX. They even has a customized VAX and monitor to visualize or analyze the captured data. The captured frame would be rendered into a gray scale image of a concentric circles that meant something to the bomb physicists. My intern project involved showing how the ridiculously expensive and fragile VAX setup could be replaced by a modern workstation running off the shelf software. Of course, this was not well received, that is why my mentor had me do the work and presentation - he would never have gotten away with it himself. No matter though, bomb testing was stopped soon enough.