CSRDRIFT after WIGGLER element

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nakamura
Posts: 13
Joined: 09 Sep 2011, 20:35

Re: CSRDRIFT after WIGGLER element

Post by nakamura » 16 Nov 2020, 05:24

Michael,

Thank you very much for your valuable information.
I also calculated the momentum spread (s6) without insertion of LSCDRIFT elements
with Effective length=0 m in WIGGLER elements and show the result in the attached figure.
The s6 slope between the entrance and exit of each undulator is almost constant and probably
corresponds mainly to LSC effects (CSR effects are small there), though unfortunately the s6
slope within the undulator is apparently zero in the figure.
If Elegant adds all the missing LSC as well as CSR at the end of the undulators as you said,
LSC effects are almost doubly added when LSCDRIFT elements are inserted into the WIGGLER elements.
I have understood the two s6 jumps I showed in the previous mail are due to overestimation (double-counting)
of LSC. Please let me know if my understanding is wrong.

 Norio
Attachments
s6-WIGGLER2.png
s6-WIGGLER2.png (4.94 KiB) Viewed 6137 times

nakamura
Posts: 13
Joined: 09 Sep 2011, 20:35

Re: CSRDRIFT after WIGGLER element

Post by nakamura » 16 Nov 2020, 20:18

Michael,

Sorry for the typo.
LSCDRIFT elements with Effective length = 0 m (LEFFECTIVE=0)
--> LSCDRIFT elements with Length = 0m (L = 0)

Norio

michael_borland
Posts: 1796
Joined: 19 May 2008, 09:33
Location: Argonne National Laboratory
Contact:

Re: CSRDRIFT after WIGGLER element

Post by michael_borland » 25 Nov 2020, 14:50

Norio,

If you have something like this
CSRCSBEND,100*(WIGGLER,LSCDRIFT),CSRDRIFT
where CSRDRIFT has LSC_BINS set to a non-zero value, then you will double-count the LSC effects in the WIGGLER. Elegant doesn't detect that there are LSCDRIFTS between CSRCSBGEND and CSRDRIFT.
Hence, you should either use LSC_BINS on CSRDRIFT elements or separate LSCDRIFT elements, not both.

--Michael

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