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asdf1
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In diffraction, why when calculating the intensity of an unpolarized X-ray beam do you have to assume that Ey=Ez if the electric field acts perpendicular to the plane of scattering (x-z) and lies in the y-z plane?
I'm not seeing the geometry. Are you saying the x-ray is traveling in the y-z plane toward the x-z plane, or are you saying E is in the y-z plane. The latter would not make sense because that would mean the x-ray is parallel to the x-axis and parallel to the scattering plane. The former has the possibility of the x-ray traveling parallel to the y-axis, in which case Ey is zero. It seems to me the relative average strengths of Ey and Ez for unpolarized light would depend on the angle of incidence to the plane.asdf1 said:In diffraction, why when calculating the intensity of an unpolarized X-ray beam do you have to assume that Ey=Ez if the electric field acts perpendicular to the plane of scattering (x-z) and lies in the y-z plane?
OK, I did misinterpret the geometry, but I'm still bothered by the equality, although it may not be important. I don't have the book, so I can't see what the author is using for a coordinate system.asdf1 said:Sorry about the confusion. The x-ray is traveling in the x-z plane and the diffrated beam can be divided into the componets of Ey=Ez. Pg.85-86 of Microstructural Characterization of Materials by David Brandon and Wayne D. Kaplan.
OlderDan said:If the incident beam is parallel to the z axis, Ez = 0. In that case you would expect to have on the average in an unpolarized beam Ey = Ex, Ez = 0. For an incoming unpolarized beam you would always expect to have equal average in-plane and out-of-plane components.
The point is that whatever the coordinate system, the incoming x-rays have the same average electric field component in the plane of incidence/reflection as the average component perpendicular to that plane.
Unpolarized light means a random distribution of polarizations. If you think of light as photons, each has its own polarization. If you think of it as waves, you have to think of unpolarized light as a mix of light beams with random polarizations. In either case, an individual beam or photon has a definite polarization vector that can be resolved into perpendicular components along any coordinate axes you choose that are perpendicular to the direction of propegation. For reflected light, the plane of incidence/reflection is a natural choice for one of those coordinates, with the direction perpendicular to the plane for the other coordinate.asdf1 said:Um... I need to ask a stupid question... Can you explain why the average has to be equal (Ey=Ex)? I'm still a little confused here...
Diffraction intensity refers to the amount of scattering of a beam of X-rays as it passes through a material. It is dependent on factors such as the wavelength of the X-rays, the composition and thickness of the material, and the angle of the incident beam.
An unpolarized X-ray beam is a type of X-ray beam that contains a mixture of different polarizations. This means that the X-ray waves are vibrating in all directions perpendicular to the direction of propagation.
The YZ plane is important in diffraction intensity measurements because it is the plane in which the diffraction pattern is typically measured. This plane is perpendicular to the incident X-ray beam and is where the intensity of the scattered X-rays is measured.
The composition of a material can affect diffraction intensity in several ways. Different elements and crystal structures will diffract X-rays differently, leading to variations in intensity. Additionally, the thickness and density of the material can also impact diffraction intensity.
The relationship between diffraction intensity and angle of incidence is known as the diffraction pattern. As the angle of incidence increases, the intensity of the diffraction peaks also increases. This is due to the increased scattering of X-rays at larger angles of incidence.