Are the goniometer circle radius and focusing circle radius same? If the material is fixed, how the radius is affecting the intensity of a signal? Can the goniometer radius be adjusted for an instrument?
On this instrument the X-ray source is stationary and both the sample stage and detector can change angle, which is theta and 2-theta. Other instrument setups can have a moving x-ray source and stationary sample stage. I think this instrument can also be setup for different scans, such as a rocking-curve scan, but I have never tried. At low angles the x-ray beam cross-section will be more distorted than at higher angles. This can influence intensity and noise. I suspect it would lead to broader peaks at lower angles because of the larger spot size, but you should double check a reference.
This machine will not operate with the alarm light on. The user being trained in this video most likely does not have the experience to diagnose the problem. The lab technician in charge of the equipment should be contacted to fix the problem. If they are unable to resolve the issue, then the manufacturer will have to be contacted for service.
This is in Bragg-Brentano geometry. The x-ray source is stationary and the sample holder and detector rotate at theta and 2-theta. It is using Cu-K radiation source.
It is safe. The user is protected from X-Rays. The glass is made out of lead oxide which absorbs X-rays. And the machine automatically stops X-rays if the door is open.
