Search found 1798 matches

by michael_borland
20 Oct 2022, 12:52
Forum: General
Topic: Highlighting mode for emacs and vim
Replies: 10
Views: 3728

Re: Highlighting mode for emacs and vim

Thanks for posting this.

--Michael
by michael_borland
20 Oct 2022, 12:50
Forum: Ring Tracking
Topic: rfmode element in a active harmonic cavity
Replies: 19
Views: 2808

Re: rfmode element in a active harmonic cavity

Chao, For item 1, we'll be releasing a bug fix soon for this issue. For item 2, the reason the generator phase varies is that it reflects the change in arrival time of the bunches, which reflects their finding equilibrium positions under the influence of beam-induced rf transients. If you reduce the...
by michael_borland
20 Oct 2022, 12:34
Forum: General
Topic: sddsanalyzebeam Twiss parameters
Replies: 7
Views: 164

Re: sddsanalyzebeam Twiss parameters

Adam,

Are you using the -correctedOnly option on sddsanalyzebeam, to get the true beta functions (with suppression of dispersive effects)? Either that, or look at the betacx, betacy, etc, values.

--Michael
by michael_borland
10 Oct 2022, 11:51
Forum: Ring Tracking
Topic: rfmode element in a active harmonic cavity
Replies: 19
Views: 2808

Re: rfmode element in a active harmonic cavity

Chao, One issue with the phase plots is just a matter of the phases being close to -pi, which causes them to wrap to +pi. You can fix this with sddsprocess 200mA.rfhc -redefine=col,%s,"%s 0 > ? pop 2 pi * - : pop $ ",units=rad,select=Phase* When you do this, you'll noticed that the phases are "noisy...
by michael_borland
06 Oct 2022, 19:30
Forum: Ring Tracking
Topic: rfmode element in a active harmonic cavity
Replies: 19
Views: 2808

Re: rfmode element in a active harmonic cavity

Chao, IDSlotsPerBunch needs to be the same on all pages. This isn't checked, but if it isn't done things will get messed up. The reason is that this is a global parameter that is used to group particles into bunches according to the particleID values. The page structure of the file ends up being ign...
by michael_borland
06 Oct 2022, 13:17
Forum: Ring Tracking
Topic: rfmode element in a active harmonic cavity
Replies: 19
Views: 2808

Re: rfmode element in a active harmonic cavity

Chao, Your file train.sdds has an issue: you set IDSlotsPerBunch = 1, but your particleID values are 1, 11, 21, ... This confuses RFMODE's bunch finding algorithm, causing it to think there are buckets you want to simulate between the bunches. The simulation is still the same, but the output becomes...
by michael_borland
05 Oct 2022, 20:22
Forum: Ring Tracking
Topic: rfmode element in a active harmonic cavity
Replies: 19
Views: 2808

Re: rfmode element in a active harmonic cavity

Chao, I think the problem was just some typos in the definition of the RFMODE element for the harmonic cavity. See attached. Also, be sure that the macro <qin> is defined to something non-zero. I did see output in the feedback file. Please be aware that asking for this output at small intervals will...
by michael_borland
05 Oct 2022, 19:45
Forum: General
Topic: Slice dispersion?
Replies: 2
Views: 3884

Re: Slice dispersion?

Adam, The dispersion, beta functions, and other properties can be defined for the lattice or for a beam (or slice of a beam). In defining these for a lattice, we have to give an initial condition or declare some boundary conditions (typically periodicity). For a beam, the properties are defined from...
by michael_borland
05 Oct 2022, 19:31
Forum: Ring Tracking
Topic: RFMODE with multiple bunches
Replies: 4
Views: 2304

Re: RFMODE with multiple bunches

Alexis,

The problem is that there's a bug that shows up when the CHARGE parameter is used on RFMODE. This parameter is deprecated, although the manual doesn't say that. You should use a CHARGE element instead. I'll revise the manual to make this clear.

See attached.

--Michael
by michael_borland
19 Sep 2022, 15:26
Forum: General
Topic: General Physical Aperture
Replies: 2
Views: 1659

Re: General Physical Aperture

Marco, There are many ways to define apertures in elegant, each with advantages and disadvantages. You can use various beamline elements APCONTOUR defines an aperture an (x, y) contour. The aperture can be localized or can be applied to downstream elements. ECOL defines an elliptical (or superellipt...