Difference between fractional tune in ADTS tracking and working point

[Kowthar_Noori]

Hello Michael and all,
I calculated the tune shift with amplitude by tracking and using SDDSNAFF. I found the following graphs for the horizontal and vertical directions.

Tune y.png (6.44 KiB) Viewed 1022 times

Tunex.png (6.85 KiB) Viewed 1022 times

Now the problem is that the value of the fractional tune at the (x0=0, y0=0) is (0.32, 0.16) which does not match the tune of the working point (44.29, 18.17).
I assume the energy of particles may affect the results. The energy of the particle is 3 GeV, I did calculations by very low energy about 1 eV and 1000 eV. The energy of particles does not affect the results.
I calculated the Twiss but it shows the same results i.e. working point is (44.29 and 18.17), and the fractional tune is 0.32 and 0.16.
I have attached the lte and ele files. Could you give me a comment?
Thank you in advance,
Best regards

[michael_borland]

The problem is that you are not using sufficient accuracy for the integration of the CSBEND, KQUAD, and KSEXT elements. You can either increase the N_KICKS parameters or switch to the 6th-order integrator. The latter is easy, just put "INTEGRATION_ORDER=6" in the definitions of those elements. Once I do that, the working point and tracking results agree.

If speed becomes a concern, I recommend using the 6th-order integrator and judiciously reducing N_KICKS to get the desired accuracy.

--Michael

[Kowthar_Noori]

Hello Michael,
I did it and my problem is solved. I really appreciate your help.
Thank you.
Kowthar