search

ocelot-collab / ocelot

OCELOT is a multiphysics simulation toolkit designed for studying FEL and storage ring-based light sources.
GNU General Public License v3.0
84 stars 58 forks source link

function matching #224

Closed SchroederSa closed 5 months ago

SchroederSa commented 5 months ago

Is there a convenient way to match the beamline for a particular function? More explicitly, I would like to minimize chromaticity or even the chromatic amplitude at a certain point of a beamline. The first is a pure analytic problem that could be solved on paper. However, minimizing the chromaticity amplitude requires a more diligent treatment and proper beam tracking - especially when LSC kicks in. Thanks for your help! Sarah

sergey-tomin commented 5 months ago

Hi Sarah,

We have a matching function which can be used to match Twiss functions: link. In case you need something different, I would recommend creating your own error function and using optimization functions from scipy.optimize to find a solution. You can find some examples in the link above, and I also have a simple tutorial where you can find another example. https://github.com/ocelot-collab/ocelot/blob/master/demos/ipython_tutorials/accelerator_optim.ipynb

Cheers, Sergey.

SchroederSa commented 5 months ago

Excellent, thank you, Sergey! Sarah

alexanatoly commented 5 months ago

Hi @sergey-tomin ,

I am looking for optimization of an electron bunch length.

I found that you applied a beautiful methodology to minimize the beam size along the transverse direction (x-y plane) in this tutorial https://github.com/ocelot-collab/ocelot/blob/master/demos/ipython_tutorials/accelerator_optim.ipynb

Is it possible to apply similar methodology for minimizing the electron beam length along the propagation direction (x-s or y-s plane) i.e. achieving a minimum bunch length from a chicane ?

Best, Alex

sergey-tomin commented 5 months ago

hi @alexanatoly,

sure it is possible. just instead of quads strength you can use cavity phase and voltage and bunch compressor R56.

Cheers, Sergey.

alexanatoly commented 5 months ago

hi @sergey-tomin

thanks for replying. I just want to optimize the beam length, trying to achieve as short as possible (I am playing with electron beam + chicane only). Do I still need cavity phase and voltage ?

sergey-tomin commented 5 months ago

Of course, you can solely use the chicane. As I mentioned earlier, you will adjust R56. In that scenario, you only have one parameter to consider, and analytics can likely be employed. I would recommend looking into tutorial N9. It covers some simple cases of a beam compressor - https://github.com/ocelot-collab/ocelot/blob/master/demos/ipython_tutorials/9_thz_source.ipynb

alexanatoly commented 5 months ago

@sergey-tomin thanks for further comments.