divide and inserting elements

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Max
Posts: 50
Joined: 31 Jul 2008, 12:16

divide and inserting elements

Post by Max » 08 Dec 2011, 16:13

Hi Michael and collaborators,

are you aware of an optics problem when splitting SBEN in 2 sections with divide_elements and inserting another element (a kicker of zero length and strength) in between
the 2 sections (insert_elements) ? The tunes seem to change when I do that, as compared to not splitting the SBEN and not inserting the kicker.

Thanks, best regards, Max

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

Re: divide and inserting elements

Post by michael_borland » 09 Dec 2011, 09:30

Max,

I'm surprised by this. I did a test with a lattice containing a large-angle dipole and I didn't see any change. Can you post an example file?

--Michael

Max
Posts: 50
Joined: 31 Jul 2008, 12:16

Re: divide and inserting elements

Post by Max » 09 Dec 2011, 10:36

Dear Michael,
in that case, I am sure I am doing something wrong...
I attach two .ele files (divided and undivided dipoles) and the .lte file.
I find:
divided dipoles: nux=6.739, nuy=6.845
undivided dipoles: nux=7.356,nuy=6.519

Thanks a lot,

Max
Attachments
umer.lte
(25.79 KiB) Downloaded 238 times
undiv.ele
(594 Bytes) Downloaded 254 times
div.ele
(754 Bytes) Downloaded 262 times

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

Re: divide and inserting elements

Post by michael_borland » 09 Dec 2011, 13:40

Max,

Actually, it was my mistake. My test wasn't valid.

There is a an issue here. You can workaround it by turning off the edge effects on the interior parts. To do this, add the following statements after the &replace_elements command:

&alter_elements name=B*, type=SBEN, item=EDGE2_EFFECTS, value=0, start_occurence=1, end_occurence=1, verbose=1 &end
&alter_elements name=B*, type=SBEN, item=EDGE1_EFFECTS, value=0, start_occurence=2, end_occurence=2, verbose=1 &end

--Michael

Max
Posts: 50
Joined: 31 Jul 2008, 12:16

Re: divide and inserting elements

Post by Max » 09 Dec 2011, 14:36

Thank you Michael. It works.

Best regards, Max

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