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emittance, coupling and radiation integrals with UKICKMAP element

Posted: 23 Feb 2023, 13:10
by blanco-garcia
Dear all,
is there a way to extract the equilibrium emittance, coupling and radiation integrals of a lattice with an UKICKMAP element ?

Best regards,
o

Re: emittance, coupling and radiation integrals with UKICKMAP element

Posted: 04 Apr 2023, 12:31
by michael_borland
You can get the radiation integrals, but only if you set the KREF or KACTUAL parameters to the K value of the undulator. You also have to set the LENGTH and PERIODS parameters. Internally, elegant just uses the WIGGLER element to get the radiation integrals. The kickmap isn't involved, so this is just a convenience and will only be a good approach for horizontal-plane sinusoidal wigglers and undulators.

If you also set SYNCH_RAD=1 and ISR=1, you can also get radiation kicks during tracking or for beam moments calculations. However, once again this is not linked to the kickmap per se, since we can't get the magnetic fields from the kickmap. It is entirely based on a simple sinusoidal field model.

If you want a more sophisticated approach, you can use CWIGGLER or BGGEXP. These compute the actual magnetic fields along the particle trajectories, so beam moments calculations are performed self-consistently. For CWIGGLER, you can also get approximate radiation integrals using a sinusoidal approximation. For BGGEXP, that isn't possible at present.

--Michael