optimizing off-momentun and on close orbit

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roblin
Posts: 7
Joined: 05 May 2010, 11:50

optimizing off-momentun and on close orbit

Post by roblin » 06 Oct 2010, 09:49

I have a lattice for which I compute the off-momentum closed orbit. When I subsequently track with
center_on_orbit=1 and center_momentum_also=1 with track everything works as expected.
In my closed orbit command i have start_from_centroid=1 and start_from_dp_centroid=1.


However, if instead of tracking, I want to do an optimization with the optimize command, it does not find the closed orbit when starting the optimization. It tells me:
"error: no beam present for closed-orbit calculation starting from centroid"

roblin
Posts: 7
Joined: 05 May 2010, 11:50

Re: optimizing off-momentun and on close orbit

Post by roblin » 06 Oct 2010, 17:16

This also happens with analyze_map. For some reason, I can not specify start_from_centroid=1 and/or
start_from_dp_centroid=1 in the closed orbit command. If i do that, then the analyze_map fails saying there is no beam.
Setting those options to zero makes it work but then of course, I am tracking on momentum.

Am i not understanding how closed_orbit is supposed to work?

Note that if i replace the analyze map by a track command
with center_momentum_also=1 and center_on_orbit=1, i can specify an off-momentum closed orbit and sucesfully track and produce the
correct closed orbit.




see attached .ele and .lte.
Attachments
supercell.lte
(1.82 KiB) Downloaded 796 times
analyzemap.ele
(963 Bytes) Downloaded 798 times
trackoffmomentum.ele
(979 Bytes) Downloaded 841 times

michael_borland
Posts: 1933
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: optimizing off-momentun and on close orbit

Post by michael_borland » 07 Oct 2010, 08:54

Yves,

The problem is that elegant doesn't generate a beam when you use analyze_map, even if you give a bunched_beam command. I'm looking into a workaround or patch.

--Michael

michael_borland
Posts: 1933
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: optimizing off-momentun and on close orbit

Post by michael_borland » 07 Oct 2010, 09:03

Yves,

The attached file will patch the analyze_map problem. Give it a try and let me know of any problems.

Can you post an example for the optimization problem?

--Michael
Attachments
elegant.c
(96.41 KiB) Downloaded 778 times

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