The calculated refraction index is much different with XOP software. about xraylib HOT 4 CLOSED

@srio what do you think is happening here? I guess we are using rather different values for the attenuation coefficients?

from xraylib.

Yes. It is due to attenuation. The differences should appear in beta and it is due to the absorption cross section.

In XOP we were using absorption due to only photoelectric effect.

In xraylib we discussed this issue many years ago and concluded that it is more accurate to include the total cross section, thus including inelastic and also Rayleigh cross sections.

In OASYS/XOPPY we are also using the same philosophy than in xraylib, so the results in OASYS/f1f2 are different than in XOP/xf1f2. I would suggest to use better OASYS instead XOP. Almost all functionality is there. XOP is not longer maintained.

Depending on the type of calculation you do the xraylib absorption may be overestimated: it consider "absorbed" (in fact: attenuated or removed from the beam) all photons that interact. If your interest is to calculate the power load this is "too much" as there are many photons that may scape and do not contribute to the absorbed energy.

I hope this clarifies the situation.

from xraylib.

Thanks @srio for the clarification! I honestly completely forgot that we ever discussed this!

from xraylib.

@srio Thanks a lot for the clarification! It is useful to help me understand the difference between them. And also thanks @tschoonj to help me get the right answer.

from xraylib.