[alexander_busek]

This produced a spike of radiation so intense there was a brilliant flash of blue Čerenkov radiation.

I wouldn't have thought that the difference in the phase velocity of light in air at s.t.p. as compared with in a vacuum would suffice for the charged particles released by such an accidental event to create a noticeable amount of Čerenkov radiation.

Can you elucidate?

Regards,

[thackney]

http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/cherenkov.html

[Boogieman]

It don’t think air that was the medium which caused the Cerenkov radiation. Remember, gamma rays are photons, and they are being emitted from inside the fissile material, before they reach the air outside. It was probably within the medium of the fissile material itself that the Cerenkov radiation was generated.

[Mr. K]

Cherenkov radiation>

[Mr. K]

The velocity of light through ANY medium is slower than in a vacuum, and so Cheronkov radiation is possible when the velocity of the particles exceeds the velocity of light in that medium