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Computation of the bunching factor
Posted: 15 Sep 2014, 11:10
by headdoggy64
Hello all,
Just wondering, if there is a standard way in Elegant/SDDS to compute a bunching factor:
Code: Select all
n(\omega) = \sum{\exp{ I \omega t_i}}^2
I tried to search the forum, but haven't found it.
Thanks.
Re: Computation of the bunching factor
Posted: 15 Sep 2014, 16:49
by michael_borland
Sorry for the delayed reply. I was on vacation.
You can use the program sddsprocess to compute the bunching factor:
Code: Select all
sddsprocess output.sdds -pipe=out -define=parameter,omega,1e10 \
"-define=col,CosWt,omega t * cos n_rows /" "-define=col,SinWt,omega t * sin n_rows /" \
-process=CosWt,sum,ReB -process=SinWt,sum,ImB \
| sddsprintout -pipe -parameter=??B
Presumably a histogram followed by an FFT would give you the bunching factor vs omega, but you'd need to watch out for numerical factors. Use sddshist followed by sddsfft for this.
--Michael
Re: Computation of the bunching factor
Posted: 06 Apr 2015, 15:08
by michael_borland
N.B.: a future release (before summer 2015) will include a program (sddsbunchingfactor) to compute bunching factors.
--Michael
Re: Computation of the bunching factor
Posted: 04 Nov 2016, 15:10
by headdoggy64
Hello Michael,
Is it possible to add a possibility of computing the full three dimensional bunching factor of the distribution?
(For example, using Eq. 2.15 from
http://www.slac.stanford.edu/cgi-wrap/g ... -r-576.pdf)
The bunching factor will then depend on the angle \theta, which will be the angle between the detector position and the beam axis.
Thank you,
Alex