Qxy calculation in Tracewin
Qxy calculation in Tracewin
On the charts page, there is an option for calculation of Qxy in which it presumably calculates the tunes of the particles. Could you please give some information regarding what exactly are being calculated? What does the ellipse plotted in the graph stand for? Also it writes a moments.txt file. What is calculated in this file? No information is given in the documentation about this.
Re: Qxy calculation in Tracewin
Dear Rajni,
First wish you happy new year.
Qxy plot is the tune “Footprints” with Space Charge. This chart is calculated by determining analytically the coherent mode frequencies and plotting them on a spectral chart of single particle frequencies of a well-matched beam.
An example is provided in TraceWin (see "Help" menu -> "Open Examples" and select Qxy_plot.ini project).
In this example phase advance (i=0) is set to 90 deg. Due to tune depression, the average particle phase advance is set to 60 deg, but due to beam distribution type (Gaussian) each particle doesn't have the same phase advance. The frequency analysing allows to estimate that point. The accuracy depends of the number of considered periods (here 2200). The 'footprint' plot Qx,y show these phase advance dispersions. Use the toots Qxy from "Charts" page to visualyse it (see image below)
Regards,
Didier
First wish you happy new year.
Qxy plot is the tune “Footprints” with Space Charge. This chart is calculated by determining analytically the coherent mode frequencies and plotting them on a spectral chart of single particle frequencies of a well-matched beam.
An example is provided in TraceWin (see "Help" menu -> "Open Examples" and select Qxy_plot.ini project).
In this example phase advance (i=0) is set to 90 deg. Due to tune depression, the average particle phase advance is set to 60 deg, but due to beam distribution type (Gaussian) each particle doesn't have the same phase advance. The frequency analysing allows to estimate that point. The accuracy depends of the number of considered periods (here 2200). The 'footprint' plot Qx,y show these phase advance dispersions. Use the toots Qxy from "Charts" page to visualyse it (see image below)
- Qxy.png (22.62 KiB) Viewed 1620 times
Didier