storage ring issue

[ustc-cheese]

Hello Prof. Tomin
I am currently utilizing Ocelot as a storage ring tool to address some ring-based problems. However, I have encountered an issue where the lattice I provided does not yield a periodic solution, whereas ELEGANT shows a periodic solution. I would greatly appreciate your guidance on how to resolve this discrepancy. Thank you in advance for your reply.

[st-walker]

How are you using ocelot? Maybe there is a mistake in usage (or maybe with OCLEOT)

I think historically @iagapov was more responsible for the circular machine bits.

[iagapov]

I have never seen any discrepancies in linear optics with elegant. If you send me input files I can have a look at the potential issues.

…

On 26. Jul 2023, at 09:30, Stuart Walker ***@***.***> wrote: How are you using ocelot? Maybe there is a mistake in usage (or maybe with OCLEOT) I think historically @iagapov <https://github.com/iagapov> was more responsible for the circular machine bits. — Reply to this email directly, view it on GitHub <#174 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABVBP2MS6FXCLXZPDMUTLRTXSDBR7ANCNFSM6AAAAAA2YCDTUQ>. You are receiving this because you were mentioned.

[sergey-tomin]

HI,
please send a lattice of the cell in ocelot format and elegant solution for this lattice. For periodic solution I use analytics. It will be interesting to see why this approach did not give you a solution.

[ustc-cheese]

Hi,
Thank you all~ Here are my ocelot .py file and elegant .lte file at the attached zip file.
ringopt.zip

[sergey-tomin]

Hi,
I found that you use in elegant these elements
Q3: &
MULT, L= 0.2433800000000000, &
ORDER= 1, &
SYNCH_RAD= 0, &
KNL= 1.22251759449587152.4450351889917430, &
N_KICKS= 40

and

Q333: &
MULT, L= 0.1829233000000000, &
ORDER= 1, &
SYNCH_RAD= 0, &
KNL= 1.79581384805425563.5916276961085112, &
N_KICKS= 40

As far I understood it is quadruple. Why does KNL value look so strange? What is the values? and also what is the solution you got with elegant? I do not have elegant installed right now and can not check it.
Anyway, in ocelot you substituted it with multipole which is zero length element. I recommend to try with quadruple. Also check if elegant and ocelot versions are really the same.

[ustc-cheese]

Hi
Thank you.
Actually the lte file is generated by other colleges using AT-MATLAB. We have tried diffrenent type of MULT but only this format can find a peroidic solution.
When I transfer Q3 & Q333 to Quad in elegant, there appers peroidic solution.
Q3: &
KSEXT, L= 0.2433800000000000, &
K1= 5.0231, &
K2= 255.0699
Q333: &
KSEXT, L= 0.1829233000000000, &
K1= 9.8173, &
K2= 161.2832

I also have tried transfer Q3 & Q333 to Quad in ocelot with the same parameters above, there still can not make a solution.

BTW, the versions pf elegant and ocelot are all the latest.