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

Homework Help: Find max E of a photon in Compton Collision

  1. Mar 14, 2007 #1
    1. The problem statement, all variables and given/known data

    Find the energy of an x-ray photon that can impart a max energy of 50keV to an electron by compton collision

    2. Relevant equations

    ∆λ=h/mc(1-cos(theta)) where m = mass of electron
    (to be honest, not entierly sure if these are all you need, or if you need them... sorry :( )

    3. The attempt at a solution

    ∆λ=2.43*10^-12 (set theta to 90 because i am dealing with a maximum)

    corresponding change in f = c/2.43*10^-12 from above
    and since E=hf
    ∆E=510551 eV which is unfortunatly, larger than the E delivered to the electron... so CLEARLY i've stuffed up... I was planning on being able to say that the energy was 50keV + ∆E so i guess i'm on the wrong track... very wrong... any hints would be very greatly appreciated :!!)
  2. jcsd
  3. Mar 14, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper

    You are changing an equation like f-f'=c/lambda-c/lambda' into f-f'=c/(lambda-lambda'). This is WRONG! Right?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook