How does surface roughness affect spectral peak shape?

How does surface roughness affect spectral peak shape?

• A. It increases peak intensity
• B. It has no effect
• C. It only affects background
• D. It causes scattering and peak broadening, reducing peak intensity and resolution; smooth surfaces give cleaner spectra

Answer: (A)

Surface roughness causes scattering of both the incoming X-rays and the emitted fluorescent photons, leading to a broader distribution of detected photons and more diffuse background. This diffuse scattering broadens the spectral peaks and lowers their height, which reduces resolution and makes peaks harder to distinguish. A smooth, polished surface minimizes scattering, giving cleaner spectra with sharper, taller peaks and less background.

Surface roughness causes scattering of both the incoming X-rays and the emitted fluorescent photons, leading to a broader distribution of detected photons and more diffuse background. This diffuse scattering broadens the spectral peaks and lowers their height, which reduces resolution and makes peaks harder to distinguish. A smooth, polished surface minimizes scattering, giving cleaner spectra with sharper, taller peaks and less background.