SN1987A

This supernova made big news because it was the first (and so far only) one to be detected in signals other than light. Several neutrino detectors spotted it too--and they spotted it first. Current models of supernovae hold that the neutrino burst comes first, and drives the rest of the explosion--not that these energy ranges of neutrinos interact very strongly, but that there are so many of them and the star is so dense that the pressure makes the star explode.

Christian Spiering wrote a book about neutrino astronomy (currently only in German). In his description of SN1987A and his book in a newsletter he points out that the detection was a near-run thing. "In 1987, there were five detectors in the world that could be used for the detection of a short neutrino burst:"

1. Kamiokande "was switched off for a routine calibration two minutes after the arrival of the neutrinos"
2. IMB's magnetic tape was almost full and wouldn't have recorded it "unless a proud graduate student hadn’t wished to show his girlfriend the facility on Sunday evening. He drove down into the mine with her, noticed that the tape was nearly full, and exchanged it for a new one"
3. Atryomovsk: it was Soviet Army day, which was effectively a holiday, and the detector was off
4. Baksan: the director made sure it kept running despite the "holiday"
5. Liquid Scintillation Detector: nothing went wrong, except maybe the detection itself, which is disputed to this day (they saw something earlier than the rest, with a smaller detector.

Uptime is important.

It makes sense, but not what I was expecting

For parts for a simple optics demo, I searched amazon for lead glass. The first thing that came up was lead glass glasses--to protect eyes from x-rays. It looks like a good pair with .75mm lead equivalent is about $200--well worth the investment if you deal with x-rays a lot.

You'd not think you could see through lead, but lead glass can have a surprising amount of lead in it and still be quite transparent--36% of lead oxide was traditional, 40% possible. By mass. Bricks of lead glass were used in physics experiments back in the day--gammas and electrons would interact with the lead, producing showers of particles, which would produce Cerencov light in the high refractive index glass--and you could just glue a light guide and phototube on the end, because little light would be lost.