Search found 1812 matches

by michael_borland
08 Feb 2023, 10:55
Forum: Bugs
Topic: Orbit correction bug
Replies: 5
Views: 61

Re: Orbit correction bug

Ji-Gwang,

I can't duplicate the problem with version 2022.0. I've attached my files.

--Michael
by michael_borland
08 Feb 2023, 10:26
Forum: Ring Tracking
Topic: rf feedback in rfmode element
Replies: 5
Views: 157

Re: rf feedback in rfmode element

Chao, This is outside my expertise, but I understand that there are various methods to transform a digital filter into an analog equivalent and vice-versa. In our 2015 IPAC paper on rf feedback, my colleague Tim Berenc recommends using a bilinear transform. The reference is to M. Santina et al. W. S...
by michael_borland
07 Feb 2023, 15:32
Forum: Bugs
Topic: Orbit correction bug
Replies: 5
Views: 61

Re: Orbit correction bug

Ji-Gwang,

Thanks for the lattice file. Can you also post the .ele file?

--Michael
by michael_borland
07 Feb 2023, 15:29
Forum: Optimization and Matching
Topic: Optimizing the quadrupole strengths
Replies: 13
Views: 26548

Re: Optimizing the quadrupole strengths

The problem is that the tracking.ele file isn't constructed correctly to generate the .twi file. See the attachment for a file that should work. (Basically, requesting a twiss output file during an optimization isn't supported. It has to be done after the optimization in a second sequence.) --Michael
by michael_borland
06 Feb 2023, 18:47
Forum: General
Topic: Centroid Shift without any magnet alignment error
Replies: 4
Views: 136

Re: Centroid Shift without any magnet alignment error

The reason for this is that your beam line contains dipole magnets with small bending radii. There are sextupole-like terms present in such magnets due to the small radius of curvature of the coordinate system. This results in distortion of the phase space, which shows up as a small centroid error. ...
by michael_borland
06 Feb 2023, 18:34
Forum: Bugs
Topic: Orbit correction bug
Replies: 5
Views: 61

Re: Orbit correction bug

Ji-Gwang,

There may have been some changes in orbit correction methods that affect your simulation. However, without the files I can't tell.

Please upload all the files necessary to reproduce the problem.

--Michael
by michael_borland
06 Feb 2023, 18:33
Forum: Ring Tracking
Topic: Pelegant Error: Unable to read ascii file with SDDS_MPI
Replies: 1
Views: 38

Re: Pelegant Error: Unable to read ascii file with SDDS_MPI

Ji-Gwang,

The problem is that Pelegant can't read ASCII files using parallel I/O. Just convert the files to binary form:

Code: Select all

sddsconvert -binary <filename>
--Michael
by michael_borland
06 Feb 2023, 18:31
Forum: Optimization and Matching
Topic: Optimizing the quadrupole strengths
Replies: 13
Views: 26548

Re: Optimizing the quadrupole strengths

The 40-cm depth is defined by the D2 element, which defines the drift space between the last quadrupole and the end of the beamline.

--Michael
by michael_borland
06 Feb 2023, 18:28
Forum: Optimization and Matching
Topic: geneticoptimizer example
Replies: 2
Views: 117

Re: geneticoptimizer example

Using the Java or Tcl/Tk SDDS editor is a good approach. One can also use "sddsconvert -ascii <filename>" and then edit the file with any text editor; its a good idea to use sddscheck to validate the file after editing by hand.

--Michael