Question about toroidally bent crystal in Laue geometry

[luweb]

Hello, I was wondering if there is a way I could get a toroidally bent crystal in Laue geometry. I couldn't find that specific option built into oes, but is there an alternative approach you would suggest? I am asking because I am trying to simulate sagittal focusing with asymmetric Laue crystals.

Thank you very much for your support.

Best Regard,
Lucas

[kklmn]

Hi,

See the docs for BentLaue2D class and an example for it: examples/withRaycing/03_LaueMono/04_sagittal_bending.py.

[luweb]

Thank you Konstantin, that is very helpful. After playing with the BentLaue2D class I just have one more follow up question: Is there a built-in way to vary the sagittal bending radius? Or any alternative strategy to accomplish that? I was thinking about stacking multiple bent crystals together with different radii, but I am not sure if that is the best approach. Thank you!

[kklmn]

The easiest way is to assign to the Rs field of the optical element instance a new value. The best place for this is in a generator where you can loop over a list of predefined values. Look for generator in the supplied examples.

[luweb]

From what I understood about the generator is that it automatizes a sequence of ray tracing runs. Sorry for not being clear before, but what I meant by varying the sagittal bending radius was varying with respect to energy, so that rays of different energies will "see" different radii. The final geometry would be a "warped" toroid. Is it possible to implement something like that in xrt with generator or another method?

[kklmn]

You are free to implement any geometry by defining two methods: local_z(x, y) for surface height and local_n(x, y) for surface normal. If you don't want a double parabolic shape, you don't need this class (BentLaue2D), just build your own.

[luweb]

Got it, thank you very much for the guidance, I will try that!