Electron beam optics after Undulator using a dogleg type achromatic bend

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Sarvesh
Posts: 4
Joined: 19 May 2020, 09:49

Electron beam optics after Undulator using a dogleg type achromatic bend

Post by Sarvesh » 28 May 2020, 08:14

Dear Michael

I am a beginner in this code. I have designed an achromatic bend using GICOSY code and then try to compare results using Elegant. But findings are little different specialy in the evaluation of etax which is [X,D] in GICOSY code. Pls see the attched files. Why etax is not coming to zero at the end of the line? Whereas [X,D] is zero in the GICOSY code simulations. Pls see the attched files.

etax = [X,D] (Blue Line in the curve) should be zero at the end of the line.

Thanks and Regards
Sarvesh Kumar
Attachments
Beta and Eta profiles.png
lattice.lte
(638 Bytes) Downloaded 121 times
run.ele
(1.17 KiB) Downloaded 116 times
Last edited by Sarvesh on 06 Jun 2020, 06:49, edited 3 times in total.

Sarvesh
Posts: 4
Joined: 19 May 2020, 09:49

Re: Electron beam optics after Undulator using a dogleg type achromatic bend

Post by Sarvesh » 06 Jun 2020, 05:51

I am struggling to define Q1,Q2, Q3 and Q4 as variable and fit the output in such a way that R16=R26=0 (Achromatic condition) and a double focusing at the output. Pls help me in this regards. I can do same things in other codes but not able to fix here, Pls modify the files to include this variation and mathching.

Pls see the sigma profiles which i am getting by above files.
Attachments
Sigma profiles.png
Last edited by Sarvesh on 06 Jun 2020, 07:07, edited 1 time in total.

Sarvesh
Posts: 4
Joined: 19 May 2020, 09:49

Re: Electron beam optics after Undulator using a dogleg type achromatic bend

Post by Sarvesh » 06 Jun 2020, 06:58

sddsprocess run.twi run1.twi "-define=column,sqbx,betax sqrt" \ "-define=column, sqby,betay sqrt " \

Why the above command gives this error ?

argument \ is invalid: too many filenames (sddsprocess)

Sarvesh
Posts: 4
Joined: 19 May 2020, 09:49

Re: Electron beam optics after Undulator using a dogleg type achromatic bend

Post by Sarvesh » 06 Jun 2020, 07:17

Pls note in above file, I am having edge angles in both dipole magnets in such a way that they focus in verticle plane. Means, edge angles are positive despite of bending angle being negative for first dipole magnet. Pls comment on this. I hope, this is practically feasible.

michael_borland
Posts: 1927
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: Electron beam optics after Undulator using a dogleg type achromatic bend

Post by michael_borland » 10 Jun 2020, 18:31

Sarvesh,

I can see several possible problems. First, although you are trying to make etax(s) antisymmetric about the Q2 magnet, your dipoles are not antisymmetric, since B1 has ANGLE<0, E1>0, and E2>0, while B2 has ANGLE>0, E1>0, E2>0. So there's no way to get the solution you want. Maybe you mean to put E1=E2=ANGLE/10 in all cases.

The attached files show how to get a solution under this assumption.

The problem with

Code: Select all

sddsprocess run.twi run1.twi "-define=column,sqbx,betax sqrt" \ "-define=column, sqby,betay sqrt " \
is that you have spurious \ characters in the middle of the command and at the end. Those are used in the unix shell for line continuation.

--Michael
Attachments
lattice.lte
(640 Bytes) Downloaded 123 times
optimize.ele
(1.02 KiB) Downloaded 131 times

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