@anders @neauoire I'm currently building a page with resources (still not done), but if you want to do some research on your own, these tubes have many names:
Solar Vacuum Tubes, Solar Evacuated Tubes, and Solar Collector Tubes.
If you append "oven" to that you should find some other write-ups on it.
@anders @neauoire I'd also recommend this page to start: https://www.dusoleildansnosassiettes.com/en/tube-de-sterilisation-solaire (in French there's an English translation)