This is an image obtained from muon radiography of Japan's Asama volcano. Credit: H T M Tanaka.
"TeV muons from γ ray primaries ... are rare because they are only produced by higher energy γ rays whose flux is suppressed by the decreasing flux at the source and by absorption on interstellar light."[1]
Muon decay produces three particles, an electron plus two neutrinos of different types.
