Optical Element "Screen"

[CFGrote]

This is a suggestion for adding an optical element that acts like a screen. It can be used to dump the wavefront at the screen's position to a file. In this way, we could trace the the WF as it propagates through the beamline more easily. Right now, to achieve this, I have to comment the later parts of the beamline, propagate, save, then uncomment the next element, run and save again etc. By inserting screens at interesting points in the beamline, this becomes more flexible and user friendly. By default, it should dump the entire WF (no resize, clipping, resampling etc.), such that a dumped WF could be used to restart the propagation from that point. A default filename could be taken from the distance from the source.

Or maybe this exists already and I'm just too blind to see it ;)

[samoylv]

I'm not sure it can work - from mathematical point of view the container ( or beamline) which consists of appended propagators, is as a whole the kernel of Fresnel integral that is solved for propagation. You can split the beamline in few ones and dump intermediate WFs in files - it may reduce accuracy but should work

[CFGrote]

hm. what about the optical_elements.Empty class? it's almost what i want, except for dumping the WF.

[samoylv]

we should ask about Empty propagator implementation details @buzmakov , but I am pretty sure, that the Empty can be only the last one element there, and it is special hacking in SRW library to cope

[CFGrote]

yes, i just saw it. will not work.

instead i'm writing a stepwise propagation in prop/propagate_s2e that does the job. almost done.

carsten

On 03/29/2017 03:29 PM, samoylv wrote:

we should ask about Empty propagator implementation details @buzmakov https://github.com/buzmakov , but I am pretty sure, that the Empty can be only the last one element there, and it is special hacking in SRW library to cope

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[CFGrote]

112

implemented stepwise propagation in propagate_s2e in prop module. in test case, the final step gives the same result as propagate():

Stepwise propagation:

One-go propagation: