Elegant users forum

Michael,
There is rather annoying bug in QUAD element with HKICK or VKICK steering used. If you divide the quadrupole using "divide_elements" command then the steering kick value is simply copied to each slice. This results in many-fold increase in overall steering.

Thanks.
Alexey.

Michael,

Please consider some day include the quadrupole and dipole fringe fields into KQUAD and CSBEND elements.
Fringe field effects often have a big contribution into the amplitude dependent tune shift and dynamic aperture:
http://accelconf.web.cern.ch/AccelConf/ ... 4_1033.PDF

Alexey.

It looks like this tune shift in KQUAD comes from the v_z * H_y term in the Lorents force. In qaudrupole vertical magnetic field is H_y = G * x Then horizontal Lorentz force is F_x = (e/c) * v_z * G * x The motion is linear as long as we assume v_z to be constant. This is only approximately true sin...

Michael, Why does KQUAD element like this one (without nonlinearities) generate some significant amplitude dependent tune shift? KQUAD, N_KICKS=10, L=0.3, K1=+4.00 Are there any hidden nonlinearities (like fringe fields or something) that are taken into account? Matrix version of this quadrupole of ...

I guess the effect of corrector length should be important if there is some significant betatron phase advance along that steering element. I've found a simple workaround: the effect of FSE in a bend can be replaced with two HKICKs at the beginning and at the end of the magnet. For a coasting beam (...

Dear Michael, I think there is a bug in the correction_matrix_output command then BEND.FSE is used as steering element. Closed_orbit command gives a different result. Please take a look at this example script. I would like to use BEND.FSE in a response matrix fitting. Is it supposed to be used that ...

Orbit response matrix fitting does not work in new elegant 20.0:

This is the responseMatrixFit4 example:

> [petrenko@localhost]$ elegant match1.ele
> ...
> Error: Memory is not allocated (matrix_mult)!

Thank you, Michael! I see the point now. This is the SDDS-edit, not the interactive edit as I expected.
Still, links + tcl-dialogs may add some interactivity into the sddsplot.

Hi! I figured out how to plot quite a nice picture of accelerator layout using floor_coordinates command in Elegant. I hope somebody will also find this simple script useful. In this connection I would like to suggest a number of new features for sddsplot: 1) Make it possible to keep the same aspect...

Thanks a lot!
It's quite hard to guess. Probably it makes sense to set the default "skip" to 1.