I located the original research:
'Multiradionuclide Evidence for an Extreme Solar Proton Event around 2,610 B.P.' 2023 Frontiers Media S.A.
which contains the 774/775 event.
It's a really comprehensive investigation, and the references open up to a lot more research done which informed this work.
A boat load of statistical analysis and evidential caveats which helped them nail down the quanta.
10-Berylium, 36-Chlorine, and 18-Oxygen isotopic assays were also employed.
Events for:
774/775 CE
994/995 CE
1052 CE
1270 CE
5259 CE
5411 CE
7176 CE
I learned a lot.
