Emittance meausrement

[Max]

Hi Michael and collaborators,

I am trying to simulate the quadrupole scan emittance measurement with sddsemitproc,
and there are a couple of points that are not clear to me.
I have a line as follows:
starting point - quadrupoles - accelerator sections - One quadrupole used for scanning -
Drift - Screen

-The manual says that
"The beam parameters computed by sddsemitproc pertain to the beginning of whatever
system is simulated in elegant". I assume this to mean (in my line above) the "starting point" and not
the quadrupole I am scanning.
This is true for the emittance, as well as the Twiss parameters ? What is the effect of
acceleration between the start of the system and the quadrupole/screen ?
What point in the line do the Twiss parameters in the output file refer to ?
I thank you in advance for your clarification,
Regards, max

[michael_borland]

Max,

The emittance and twiss parameters will all pertain to your "starting point". Since sddsemitproc knows the matrix from the starting point to the screen, including acceleration, it should properly account for the effect of acceleration and give you the initial emittance.

The only limitation I'm aware of is that it doesn't handle dispersion at the screen correctly.

--Michael