However, the intensity drop also depends on the alignment of sample and goniometer as well as the size of the collimator, receiving slit, the tilting angle Ps of a sample and the Bragg angle
th of diffraction.
It is also interesting to see that Kogelnik's theory predicts with certain accuracy the position and the size of the lobe corresponding to Bragg angle
, but a slight deviation of the Bragg angle
is also observed.
In order to achieve a deeper insight into this aspect, we analyzed the evolution of diffraction efficiency as a function of exposure and used the fitting of the angular response of the hologram around the first Bragg angle
to calculate the physical and optical thickness  and attenuation of refractive index modulation in depth.
On the other hand in Figure 4(b) is represented the diffraction efficiency for order -1 as a function of the angle of incidence for a grating of thickness d = 20 [micro]m, again a great similarity between the results can be seen, although some discrepancies appear far from the Bragg angle
. These discrepancies are due to the fact that Kogelnik's theory makes some assumptions, whether the one proposed not.
The molecular orientation of the PCL crystal (110 plane) was measured using the strongest reflection at the Bragg angle
of 20 = 21.4[degrees].
In order to compare the resultant equation with the results, it is necessary to transfer to the angular variable - deviation from the exact Bragg angle
where [theta] is the Bragg angle
, p is the (002) peak width at half height
The other potential advantage of the TXRF technique stems from the fact that the grazing angle of incidence is much smaller than the Bragg angle
, named after the father and son pair who received the Nobel Prize in Physics for this work in 1915.
The Bragg angle
for the stage-1 K monochromator is 56.6[degrees].
Early production holograms developed dark spots when stored under pressure (ie stacked), which the company tracked down to problems with the laminating adhesive, which would deform, causing strain on the plastic and therefore shifting the Bragg angle
. The company has now developed two new pressure-sensitive adhesives (PSAs) to overcome this problem.
Conventional x-ray diffractometers are designed so the angle at which the beam strikes the sample is permanently set at 0.5 Bragg angle
[for maximum x-ray scattering]."