Search found 19 matches

by jcalvey
05 Jul 2023, 17:07
Forum: Ring Tracking
Topic: Settings of new 'poisson' method in 'ion-effects'
Replies: 6
Views: 851

Re: Settings of new 'poisson' method in 'ion-effects'

Siwei,

Can you post or email me the input files you are using?

-Joe
by jcalvey
23 Jun 2023, 15:27
Forum: Ring Tracking
Topic: Settings of new 'poisson' method in 'ion-effects'
Replies: 6
Views: 851

Re: Settings of new 'poisson' method in 'ion-effects'

Hi Siwei,

I have not seen a horizontal instability in my Poisson simulations. My suggestion is to increase the number of ion macroparticles generated per bunch. If you have only a few high charge macroparticles, that could cause a numerical instability.

-Joe
by jcalvey
05 Jun 2023, 17:37
Forum: Ring Tracking
Topic: Settings of new 'poisson' method in 'ion-effects'
Replies: 6
Views: 851

Re: Settings of new 'poisson' method in 'ion-effects'

Hi Siwei, For simulations of the APS gas injection studies with the Poisson method, I've been using 128x1024 bins (since higher resolution is desirable in the vertical plane). But this is probably overkill; simulations with 64x512 bins seem to give the same answer. I'm still playing around with this...
by jcalvey
01 Nov 2022, 12:37
Forum: Ring Tracking
Topic: bigaussian method in ion-effects
Replies: 4
Views: 2394

Re: bigaussian method in ion-effects

Hi Siwei, Interesting results! The "gaussian" option doesn't actually do a fit, it just uses the total charge and sigma within a certain range of the beam centroid. You can increase this range by increasing the gaussian_ion_range parameter. You could also try the "gaussianfit" option, which tries to...
by jcalvey
20 Oct 2022, 16:23
Forum: Ring Tracking
Topic: bigaussian method in ion-effects
Replies: 4
Views: 2394

Re: bigaussian method in ion-effects

Hi Siwei, There are several parameters that affect the speed of the bigaussian method; the most important are ion_histogram_max_bins and ion_bin_divisor (see https://ops.aps.anl.gov/manuals/elegant_latest/elegantsu45.html#x53-520007.34). Unfortunately, for any reasonable choice of parameters, it wil...
by jcalvey
15 Mar 2022, 14:35
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 16
Views: 9885

Re: Beam ion interaction using IONEFFECTS element

All,

I've updated the ionEffects example that comes with elegant; see attached. It's actually 3 examples: with ILMATRIX tracking, element-by-element tracking, and using an arbitrary bunch pattern as input. I think it should cover most of the questions people have asked here. Hope it helps!

-Joe
by jcalvey
23 Dec 2021, 11:48
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 16
Views: 9885

Re: Beam ion interaction using IONEFFECTS element

Teresia and Tiansk,

Try downloading the script and following the instructions from my post on December 3rd. It works a bit differently than the one you have.

Teresia, I suspect you are correct that it is related to the particleID.

-Joe
by jcalvey
17 Dec 2021, 14:34
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 16
Views: 9885

Re: Beam ion interaction using IONEFFECTS element

Tiansk,

Looking through your files, it's not clear to me why train1 and train2 gave different results. If you compare the rms amplitude (ampyRms), does that also look different?

-Joe
by jcalvey
09 Dec 2021, 15:17
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 16
Views: 9885

Re: Beam ion interaction using IONEFFECTS element

Can you please suggest me how to plot the ion density since begining. Use these commands to plot the total charge in the ring, bunch-by-bunch: sddsprocess ion1.ionDens -pipe=out -define=col,cPass,Pass, -define=col,cs,s | sddscombine -pipe -merge -overWrite | sddsbreak -pipe -changeOf=cPass | sddsso...
by jcalvey
09 Dec 2021, 13:53
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 16
Views: 9885

Re: Beam ion interaction using IONEFFECTS element

tiansk wrote:When I use multi-bunch train beam fillings, the column Sy & Sx in the ebeam file are 1 for NULL bucket, so :
I'm not sure why you are getting any NULL/zero values here. Can you post the exact command you are using for makeBunchTrainWF, and your fill file?