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How to convert m meter into recoils

  1. Aug 19, 2008 #1
    Hi
    as the single photon recoil is p=hbar k
    and k=2pi/lambda
     
  2. jcsd
  3. Aug 19, 2008 #2

    Redbelly98

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    What is it you want to know? The velocity change of an atom that absorbs or emits a photon?

    Single-photon recoil can be expressed as a momentum or as a velocity. It doesn't make sense to express it as a distance (as your implying by asking about meters). Can you explain some more about what you wish to know?
     
  4. Aug 19, 2008 #3
    yes yu are right,
    I just wanna calculate the width of a velocity distribution in recoils.
    if e.g 1 pixel=2 micro meter, which is the width in pixel or microns,
    how ca we express this width in recoils.
    thanx
     
  5. Aug 20, 2008 #4

    Redbelly98

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    Here is a "3-step program":

    1. Divide the recoil momentum by the atom's (or molecule's) mass. This gives you the recoil velocity:
    vrec = hbar k / M

    2. Express the width of the velocity distribution in velocity units, such as m/s. (Not in pixels or micro meters, that is not making sense to me.)

    3. With the recoil velocity and velocity width expressed in the same velocity units, take their ratio:

    [width in recoils] = vwidth / vrec
     
  6. Aug 20, 2008 #5
    Thanx alot
     
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