A problem in Find Aperture setting

[hongjin]

Hi michael,

I am a beginner at elegant. To my understand, the Dynamic Aperture vary , which is defined in unit of realistic beam size,e.g.m,due to β is different along the ring. But I don't know how to set the position of watch in the command Find Aperture, or how to define the DA in unit of bunch σ.

Thank you!
Hongjin

[michael_borland]

Hongjin,

elegant computes the DA at the beginning of the lattice, so the relevant beta functions are from that location. The beta function values throughout the lattice can be obtained from the twiss_output command. The use of beam size to normalize the DA is, in my opinion, not very useful. It is presumably only relevant when the quantum lifetime is likely to be short, which is very unusual indeed.

You can post-process data from elegant to get the DA in terms of beam size. See the attached files.

--Michael

[hongjin]

Thank you, Michael