Chad Mitchell

All tests currently pass except Windows. Windows test fails because of trouble opening `diags/reduced_beam_characteristics_final.0.0`

As part of this PR, consider revisiting documentation labels xmax and ymax. Should these be more descriptive, eg. horizontal half-aperture and vertical half-aperture?

@kyrsjo I don't see an element exactly analogous to this one in the MAD-X documentation. However, (at least for the transverse focusing), the closest analogy is the SOLENOID. If the...

This looks great; thanks a lot! I made only a minor comment. It looks ready to go once a simple test is added. Let us know if you would like...

Thanks @nikitakuklev . It is much appreciated that you already looked into the origin of this and possible work-arounds. This would be a good topic for one of our AMReX...

@WeiqunZhang To clarify: this is supported in AMReX 25.5 and not in AMReX 25.4? If so, this would not be available until the next (May) release of ImpactX.

The attached result illustrates the improvement in numerical convergence obtained when running the expanding beam [test](https://impactx.readthedocs.io/en/latest/usage/examples/expanding_beam/README.html) with envelope tracking (`input_expanding_envelope.in`). [ImpactX_StrangSplitting.pdf](https://github.com/user-attachments/files/19511092/ImpactX_StrangSplitting.pdf)

This works, but suffers a loss of precision in certain cases (eg, uncoupled beams with et

@jonasbjorklundsvensson Yes, understood! Thanks for your comment. Please be aware that there is a long list of requested features that are required for more immediate internal project milestones, so some...

Note: The definitions of the parameters E1 and E2 need to be determined from the bend angle, and the correct relationship between the straight (projected) length and the arc length...