Friday Facts - gamma radiation

Friday again, darlings, and we know by now what day (normally) means: Friday Facts! This week I want to tell you about gamma radiation, since most of my (professional) life orbits around this kind of radiation these days.

1. gamma rays, or gamma radiation, is the same kind of radiation as light (both are "just" electromagnetic radiation) - it's just really really intense, and comes from the atomic nucleus. A gamma ray carries at least 10 000 times more energy than "normal" visible light ray
2. it doesn't have any mass or charge - as opposed to for example alpha or beta radiation
3. gamma radiation travels with the speed of light - maybe not a big surprise, since I say in number 1 that it's really the same kind of radiation as light ;)
4. gamma rays can be used to kill cancer cells, but it's not the standard for radiation treatment in Norway - where we use X-rays (when it comes to killing cells there's really no big difference between using gamma or X-rays )
5. gamma rays are kind of waves, with very high energy, and very short wavelength - of less than ten trillionths of a meter
6. gamma radiation goes through "everything" - at least compared to alpha and beat radiation, which are easily stopped. If you want to shield something from gamma radiation (and I often want to do just that), you (or I) use something very dense, like lead or actually depleted uranium is even better 
7. a nucleus will very often emit a gamma ray at the same time as it emits an alpha or beta particle; this happens because after emitting the alpha/beta, the nucleus has a lot of extra energy, which is called being excited, and to get rid of this extra energy (called "de-excite") it emits gamma radiation
8. measuring the gamma rays can be used to identify all kinds of different nuclei, since the different energies of the gamma rays sort of works like an id, or fingerprint, for one specific nucleus. For example we know for sure that oxygen-17 emits a gamma ray with an energy of 870 kilo-electron volts, and if we measure this we know that we have measured that exact oxygen isotope
9. we (people) emit gamma radiation: A person that weighs 70 kg emits 500 gamma rays that come from potassium-40 every second. Potassium is the main reason why humans are radioactive, and that's completely normal :)
10. I think it's so funny that we call a nucleus that has extra energy excited...I mean, this is me when I'm excited :D When I'm excited I don't emit more gamma rays than normal :P

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Now I have to run for our nuclear physics group meeting - but maybe I'll talk to you later today. Have a great Friday and soon weekend sweeties!