small amount of powdered material is sealed into a fine capillary tube made from glass
that does not diffract x-rays. The specimen is placed in the Debye Scherrer
camera and is accurately aligned to be in the centre of the camera. X-rays enter the
camera through a collimator.
The powder diffracts the x-rays in accordance with Braggs law
to produce cones of diffracted beams. These cones intersect a strip of photographic film
located in the cylindrical camera to produce a characteristic set of arcs on the film.
Investigate the powder diffraction
method using the simulation here, by clicking on the start button repeatedly.
Powder diffraction film:
When the film is removed from the
camera, flattened and processed, it shows the diffraction lines and the holes for the
incident and transmitted beams.
always two arcs in the x-ray beams Ka and Kb, this causes the highest
angle back-reflected arcs to be doubled. From noting this, it is always clear which hole
is for the transmitted beam and which is for the incident beam in the film.
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