Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I Question about Photon energy in Nuclear/Atomic Physics

  1. Mar 25, 2016 #1
    I picked up a book titled "Physics in Nuclear Medicine" that, while a slightly outdated edition, will presumably still have a bunch of valid fundamental information inside. One thing I noticed in it talking about EM radiation behaving as packets of energy was that it states: "The energy of the photon E and the wavelength lambda of its associated electromagnetic field are related by:"

    [tex] \text{E(keV)} = 12.4/ \lambda (\text{\AA}) [/tex]

    (On another note, how the heck do I get the Angstrom symbol to show up?)

    But my confusion was when I think of the energy of a photon or a collection of photons, I think of the formulas [tex] E = h \nu = \hbar \omega [/tex]
    or just the De Broglie relations in general where nu is the frequency, omega is the angular frequency, hbar is h/2pi, h is the normal Planck constant, etc; is this just a case of dimensional analysis where these are the same things but units need to be moved around? I can't see how that would be the case. Sure, momentum in the form [tex] P = \frac{h}{\lambda} [/tex] has frequency in the denominator...but energy for a photon doesn't. Do these equations represent the same things?

  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted