Momentum aperture and Touschek lifetime -pelegant

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adrianea
Posts: 4
Joined: 29 Nov 2011, 08:58

Momentum aperture and Touschek lifetime -pelegant

Post by adrianea » 11 Feb 2013, 07:03

Dear Michael,
Recently I've started using elegant and also parallel elegant set up on the grid for the storage ring calculation. I have a problem with calculating Touschek lifetime by using output files for momentum aperture and Twiss parameters calculating by pelegant (using 4 nodes). Namely, when I use a touschekLifetime script for calculation, the error occurs and it says that those 2 input files don’t match ?? This I tried on the windows version. On the linux version it doesn’t work either but there it claims that it cannot read layout (“Unable to read layout--no header lines found (SDDS_ReadLayout)”).
Next step I did, I calculated the momentum aperture using the same scripts by using elegant on my computer, but it takes a lot of time. This time I could calculate the Touschek life time. Looking into output for momentum aperture for both cases, I have noticed that for the pelegant the output is unsorted and maybe this is the reason that while calculating Touschek lifetime the error occures . Do you know how to fix this problem?
Please find also attached files of momentum aperture and Twiss parameters obtained by elegant (momap.mmap, momap.twi) and by pelegant (momap1.mmap, momap1.twi) additionaly the lattice file (ring531.lte) and the momap.ele script that was used for those calculation.
Best regards,
Adriana
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touschekLifetime.rar
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michael_borland
Posts: 1797
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
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Re: Momentum aperture and Touschek lifetime -pelegant

Post by michael_borland » 11 Feb 2013, 09:02

Adriana,

The problem is almost certainly the sorting issue that occurs when using the parallel algorithm. You should be able to fix it by using sddssort to put the data in the right order:

Code: Select all

% sddssort <momentumApertureOutputFile> -column=s
% touschekLifetime ...
Let me know if this doesn't fix it.

--Michael

adrianea
Posts: 4
Joined: 29 Nov 2011, 08:58

Re: Momentum aperture and Touschek lifetime -pelegant

Post by adrianea » 11 Feb 2013, 11:28

Dear Michael,

Thank you for your quick reply. The sort command works almost perfect, however it didn't solve a problem. Still cannot calculate the Touschek lifetime, because of the same problem : mismatch of twi and mmap beamlines. The problem is that I have some zero-length elements in my beamline and when it sorts the column with respect to s it changes also the elements order if they have the same s alphabetically with respect to names I guess, and this again doesn't correspond to the twi output. However thank you for the tips, I will either try to avoid those elements or will rename them to get the sorting proper, or do the sorting manually.

All the best,
Adriana

michael_borland
Posts: 1797
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: Momentum aperture and Touschek lifetime -pelegant

Post by michael_borland » 11 Feb 2013, 12:40

Adriana,

Try giving the -ignoreMismatch option on touschekLifetime. It should resolve the issue related to zero-length elements.

--Michael

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