Saigonauticon , 10 months ago

So, in the fine tradition of using bananas for scale…

Bananas are slightly more radioactive than the background, due to potassium-40 content. So an informal unit of radiation measure in educational settings is the ‘banana-equivalent-dose’, which is about 0.1 microsieverts.

My particle spectrometer saw first light today, and I figure that I could use a banana to calibrate it. Then I noticed that K-40 undergoes a rare (0.001%) decay to 40Ar, emitting a positron. So not only is a banana a decent around-the-house radioisotope source, it’s also an antimatter source.

Truly a remarkable and versatile fruit.