Need more distribution options for bunch generation

[cr-xu]

Currently Cheetah only supports generation of Gaussian bunches.

More distributions should be supported, especially allowing to specify different distributions in transversal and longitudinal plane.

For example

• Truncated gaussian bunch
• Radial uniform + longitudinal uniform (cynlindrical)
• Uniform ellipsoidal (3D uniform?)

This is also requested by @RemiLehe

[jp-ga]

Take a look at https://github.com/ColwynGulliford/distgen We should implement distgen wrappers in Cheetah at some point

[cr-xu]

Take a look at https://github.com/ColwynGulliford/distgen We should implement distgen wrappers in Cheetah at some point

That looks really nice. So in general we should also implement an converter to import from GPT / OpenPMD beam types.

[jank324]

Something else to keep in mind is that generators implemented directly in Cheetah are also differentiable ... in case someone needs that as a feature.

[jp-ga]

OpenPMD already has the functionality to read and write Astra format: https://github.com/ChristopherMayes/openPMD-beamphysics/blob/master/docs/examples/write_examples.ipynb

[jp-ga]

Something else to keep in mind is that generators implemented directly in Cheetah are also differentiable ... in case someone needs that as a feature.

That's a good point.

[jank324]

There is a dedicated issue for adding distgen to Cheetah now: #149