Benchlength at the position of every element

[CCH]

Hello,
Can you tell me how to get the bunchlength as a function of s when I do a tracking?

------------cch

[michael_borland]

If you are tracking for one pass (e.g., a linac, transport line, or a single turn in a ring), you can use the "sigma" output file from &run_setup. The "Ss" column is the bunch length, provided your beam is relativistic. See http://www.aps.anl.gov/Accelerator_Syst ... ode14.html

If you want the equilibrium bunch length in a ring, use the &moments_output command.

--Michael

[jpuntree]

Hello Michael,

Could you give more details how to get use of the &moments_output command in order to get equilibrium bunchlength as a function of s.
And what will 'Ss' means if I use it in a storage ring tracking?

Many thanks in advanced
Jatuporn

[michael_borland]

Jatuporn,

You can find an examle of using moments_output for a storage ring in the examples file, under PAR/moments. The relevant column in the output file is "s5".

Unless you set up the bunched_beam correctly (with the equilibrium beam properties as the inputs), "Ss" from the &run_setup sigma file probably won't be useful. However, if you set the beam up properly, it should give the same result as "s5" from moments output.

--Michael