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bmad-sim / bmad-ecosystem

Bmad simulation ecosystem for simulating high energy storage rings.
https://www.classe.cornell.edu/bmad/
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`P_dk` discontinuous jump when passing over half-integer spin tune #1314

Open mattsignorelli opened 2 days ago

mattsignorelli commented 2 days ago

Describe the bug Screenshot 2024-11-20 at 4 14 43 PM

When the spin tune passes over the half integer, there is a discontinuous jump in P_dk. I do not see this with older versions (6-7-8 months ago or so it's been a while) for this same lattice.

Minimal Working Example show spin is now very slow even with SPRINT tracking #1265 . Nonetheless I calculate this scan using python spin_polarization which fortunately is fast still. So I would set ele 0 e_tot to values around a*gamma = 40.5 and see the jump. Or you could use Tao.jl and run the documented pol_scan function.

mattsignorelli commented 2 days ago

esr-main-unique-1IP-CS-1.bmad.zip Here's the lattice