A magnetic field, that is experienced by a proton(a spin in MR lingo), is oscillating at a frequency \omega which is near but not exactly \omega_{0} the Lamar frequency of the spin, i.e. does not meet resonance condition. I then instantaneously alter the rate at which the magnetic field...
In MR there is the resonance condition that for a proton in a lower energy state, a photon with a frequency that matches the energy separation between states, E=hf, can transmission the proton to the higher energy state by absorbing said photon.
The question then is how long does this...
The statement as I heard/read it was 'the wavelength has to be much larger than the object being imaged'. Note: this is object size as a whole entity and not the separation between resolvable features. This reason was given as one of the requirements for MR imaging and one of the reasons imaging...
Yes, I was thinking 'the explanation the effects seen during X-Ray imaging' instead of the specific process of 'Compton scattering'. The answer to the question I asked then is, we are only talking about compton scattering.
The imaging modalities I am referring to, (X ray, MR), the photons predominately homogeneously interact with the proton/neutron/electron(s) of the atom/molecules throughout the whole object being imaged and not just the surface of the object that the photons reach first. For example in 1H MRI...
I have read the statement that 'the wavelength of the photons used in imaging an object needs to be much larger than the object itself', although I have never seen/heard a reason explained or the name of a theorem quoted. I have seen this in the description of more than one imaging modalities...
It's not compton scattering per se that has the property that a absorbed photon has a different frequency from the emitted photon, it's a property of the atom/molecule shells. The absorption and emission are separate events. To be absorbed the frequency/energy of the photon has to match the...