Talk:Cargo scanning

passive radiation detectors

I changed the previous statement that nuclear materials emit a lot of gamma photons, because there are nuclear materials such as U235 that do not emit a lot of photons. Furthermore, I corrected the word "false" alarms where in fact "nuisance" alarms were referred to. The former term is used to express an alarm occurring for statistical reasons when no radiation source is present, the latter indicating that radiation (in this case from NORM) is in fact present and correctly detected by the RPM but incorrectly assumed to be a threat. I tried expanding the section as requested. User:Unkenruf 15 January 2010

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X-rays vs Gamma-rays!

Dear all,

In the Gamma-Ray section photon energy is given as 1.25MeV whereas in x-Ray section photon energy is given as starting from 5 MeV! But Gamma rays are -by definition- more energetic than X-rays! Is there some kind of error? — Preceding unsigned comment added by 85.73.96.76 (talk) 22:07, 10 May 2020 (UTC)

Bremsstrahlung photons aren't monoenergetic, but instead span an energy spectrum, so it is a mix of both X-rays and gammas rays and everything in between (it is a continuum, after all). So while the section header isn't totally wrong, it is a bit misleading. After all, it is the high energy photons (i.e. gammas) in the bremsstrahlung spectrum that enables the stronger penetration. Unfortunately, literature tends to use X-radiography and gamma-radiography interchangeably, so there isn't a clear standard. Paydah (talk) 16:06, 30 March 2022 (UTC)