Probably a stupid car question...

[Lissa]

On a (slightly) unrelated note, just how dense does the shielding have to be to impart Bremsstrahlung from Nitrogen-16 decay? I mean, just how energetic is that beta particle event?

From Wolfram|Alpha... Nitrogen 16. During its decay back to O16, it gives off 5-7 MeV high energy gamma radiation. From Wiki, "Condensate from the condenser is typically retained for 10 minutes to allow for decay of the 16N. This eliminates the need to shield and restrict access to any of the feed water piping or pumps."

Errr...there's no gamma with the decay, just a beta. Given, you have an electron moving at relativistic speeds, but it's just an electron which will be stopped by your skin if the decay happens external to your body. If the N16 decays in your lungs however, there is definite damage potential.

I wasn't wondering about the beta event in of itself. I was wondering about the beta particle causing Bremsstrahlung (braking radiation) due to the use of very thin, dense shielding. Basically, the faster you stop a beta particle in its tracks, the higher the frequency of EM radiation it generates in the aftermath. Stop it fast enough, you boost the frequency into the range of gamma rays.

Not completely, the energy of the Bremsstrahlung is dependent on the initial energy of the incident Beta, the higher the energy of the incident Beta, the lower the energy of the Bremsstrahlung (which seems counterintuitive, but that's what's been observed for a hundred years now), so in the case of N16, the incident Beta is 5 MeV or so (which is pretty high for a Beta since the rest mass energy of an electron/positron is 0.511 MeV) so the Bremsstrahlung should be relatively low.