There is no technical information available about this project by artist Nikki Pugh, but Sol Invictus is clearly triggered by one of my geiger counter kits.
via Make:
Update: There is now an Instructable, and an article about the project @ Wired UK.
Technical information now available at http://www.instructables.com/id/Geiger-counter-triggered-LED-decorations/
It is indeed a MightyOhm Geiger counter kit – thanks 🙂
That is literally random.