Search found 46 matches

by tiansk
25 Aug 2025, 01:19
Forum: Ring Tracking
Topic: intrabeam scattering with IBSCATTER
Replies: 10
Views: 42670

Re: intrabeam scattering with IBSCATTER

Dear Michael, Under the condition smooth = 0, the current code contains: if (IBS->do_x) { G = IBS->dT * IBS->xGrowthRate[islice]; RNSigma[0] = sqrt((2 * G + G * G) * S[1][1]); } Would it be more reasonable to compute RNSigma_norm[0] = sqrt((2 * G + G * G) * S[1][1]) / sqrt(1 + alpha[0]^2) instead? D...
by tiansk
20 Aug 2025, 10:40
Forum: Ring Tracking
Topic: intrabeam scattering with IBSCATTER
Replies: 10
Views: 42670

Re: intrabeam scattering with IBSCATTER

Dear Michael, I believe that adding IBSCATTER more densely does not solve the problem of smooth=1, but rather IBSCATTER should be placed at the position where alpha=0. Additionally, I would like to ask another question. Currently, the IBSCATTER simulation only performs slicing in the longitudinal di...
by tiansk
14 Aug 2025, 22:30
Forum: Ring Tracking
Topic: intrabeam scattering with IBSCATTER
Replies: 10
Views: 42670

Re: intrabeam scattering with IBSCATTER

Dear Michael, Thank you for your reply. After reviewing the IBS-calculation code, I noticed that setting smooth=0 modifies only xp, yp and dp. While this may be closer to the actual physical IBS process, it risks numerical issues from the program’s standpoint. The way the code transforms coordinates...
by tiansk
09 Jun 2025, 04:31
Forum: Ring Tracking
Topic: intrabeam scattering with IBSCATTER
Replies: 10
Views: 42670

Re: intrabeam scattering with IBSCATTER

The change in the vertical emittance is shown in the figure below.
by tiansk
09 Jun 2025, 04:29
Forum: Ring Tracking
Topic: intrabeam scattering with IBSCATTER
Replies: 10
Views: 42670

Re: intrabeam scattering with IBSCATTER

Dear all: When using IBSCATTER to simulate the IBS effect, there is a parameter called SMOOTH in IBSCATTER. I believe that setting SMOOTH to 1 or 0 may result in different paths for the variation of beam parameters, but the final equilibrium state should be relatively consistent. However, after comp...
by tiansk
28 Apr 2025, 19:03
Forum: Ring Tracking
Topic: Calculation of Sliced Beam Parameters
Replies: 2
Views: 16352

Re: Calculation of Sliced Beam Parameters

Thank you for your detailed explanation. I understand the origin of the sqrt(4*PI) factor.
by tiansk
24 Apr 2025, 20:55
Forum: Ring Tracking
Topic: Calculation of Sliced Beam Parameters
Replies: 2
Views: 16352

Calculation of Sliced Beam Parameters

Hi, When using the IBSCATTER element for IBS simulation, under the condition of longitudinal slicing of the beam, how is the sliced bunch length statistically calculated? I checked the elegant source code and found that the sliced bunch length is given by “bLength = c_mks * tLength / sqrt(4 * PI)”. ...
by tiansk
09 Dec 2021, 21:25
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 17
Views: 193208

Re: Beam ion interaction using IONEFFECTS element

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? Hi,Joe: I may not have articulated my probl...
by tiansk
06 Dec 2021, 02:18
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 17
Views: 193208

Re: Beam ion interaction using IONEFFECTS element

Hi,Joe: Thank you for your explanation .I have another question about data processing, When I use multi-bunch train beam fillings, the column Sy & Sx in the ebeam file are 1 for NULL bucket, so : sddsprocess ion1.ebeam ion1.ebeam.break -redefine=col,ampy,"Cy abs Sy /" -redefine=col,ampx,"Cx abs Sx /...
by tiansk
19 Nov 2021, 01:13
Forum: Ring Tracking
Topic: Beam ion interaction using IONEFFECTS element
Replies: 17
Views: 193208

Re: Beam ion interaction using IONEFFECTS element

Hello Saroj, This series of commands will plot the average ion density of the APS ring: sddsprocess ion1.ionDens -pipe=out -process=qIons,last,qLast | sddscollapse -pipe | sddsbreak -pipe=in ion1.ionDens.break -decreaseOf=s sddsprocess ion1.ionDens.break -process=qLast,sum,qTot -process=Pass,first,...