I believe I was actually at this facility around the time this video was taken! I was there with a large group mixing scientists and others who were sending acrylic through it to make captured lightning/lightning sculptures/lichtenberg figures! It was a really cool experience!
One common use is cross-linking polymers. If you've ever used cable with XLPE insulation, it was initially extruded onto the wire as normal polyethylene, then spooled back and forth between drums passing under an e-beam system like this, to perform the cross-linking. It's phenomenally tough stuff after that; a lot of cars use XLPE (in its thinwall TXL spec) wiring.
In this video, it's for examining calcite according to the description; I believe I've also seen similar devices used for making lichtenburg figures in acrylic.
I believe they are used to irradiate cannabis too (to kill mould & yeast) - electron-bean irradiation retains much more terpenes than gamma irradiation does!
Yes, a lot of commercially grown cannabis is, unfortunately, irradiated. Different countries (abd different US states) have different laws about the amount of mould and yeast that are permitted on sold cannabis flowers (as well as other things, such as moisture content). The target is quite hard to meet got some markets, including the UK and EU.
To get to the required levels, irradiation isn't necessary... but it's cheap and easy. I get the sense that it's often used because of poor growing practises, more than anything else.
I can't speak for other countries, but in the UK most cannabis has until recently been gamma irradiated - which often led to practically terpless flower that smelt of damp hay. More recently, e-beam (electron-beam) irradiation has largely taken over - and it seems to be much, much kinder on terpenes! Honestly, most is now impossible to tell apart from non-irradiated flower.
I don't have actual data, I'm afraid. There's a single paper talking about cannabinoid and terpene content of cannabis after gamma irradiation, which was paid for by Bedrocan - but I haven't found anything about how it compares to e-beam.
