Search found 1761 matches

by michael_borland
02 Aug 2022, 11:16
Forum: General
Topic: Implementation of bunch lengthning and transverse impedance
Replies: 9
Views: 5150

Re: Implementation of bunch lengthning and transverse impedance

Sara,

Unless the handles reappear, I wouldn't consider that MWI. It may just be the bunch settling into the rf bucket that is distorted by potential well distortion.

--Michael
by michael_borland
02 Aug 2022, 09:43
Forum: Optimization and Matching
Topic: close orbit and response matrix when random error exist?
Replies: 2
Views: 42

Re: close orbit and response matrix when random error exist?

Chao, The coupled trajectory correction requires that only HMON and VMON elements are present in the beamline, so I converted your lattice. The attached files work for trajectory correction, but the tune correction isn't stable. Is this a ring that is strongly coupled, or a transport line? The coupl...
by michael_borland
02 Aug 2022, 09:26
Forum: General
Topic: Implementation of bunch lengthning and transverse impedance
Replies: 9
Views: 5150

Re: Implementation of bunch lengthning and transverse impedance

Sara,

I'd suggest using more particles and finer spacing of the points in current. I'd hope that will give a clearer threshold.

--Michael
by michael_borland
01 Aug 2022, 19:50
Forum: General
Topic: defining my own wiggler field
Replies: 6
Views: 67

Re: defining my own wiggler field

Do wait on Michael to confirm or deny, but yes to my understanding the synchrotron fields must be calculated ourselves, however the effects on a travelling bunch (particles) is modelled by Elegant. I had been looking at this for myself and for a classical wiggler I think the solution is to take the...
by michael_borland
01 Aug 2022, 19:50
Forum: General
Topic: defining my own wiggler field
Replies: 6
Views: 67

Re: defining my own wiggler field

ELEGANT is capable of simulating SASE FEL, right? Are you saying I can only obtain the effect the radiation does to the beam, but not the radiation spectrum? It can compute SASE FEL output using Ming Xie's parametrization. It is not a real simulation, just an approximate estimate. You need to use a...
by michael_borland
01 Aug 2022, 19:48
Forum: Optimization and Matching
Topic: orbit correction for a long beam line
Replies: 4
Views: 1775

Re: orbit correction for a long beam line

Esmaeil, Your lattice does not close upon itself. I guess this is because of insufficient precision in converting from MAD-X to elegant format. elegant is unable to obtain a closed orbit even in the absence of errors. You can use the floor_coordinate command to compute the the floor coordinates and ...
by michael_borland
01 Aug 2022, 19:36
Forum: General
Topic: TWPL increasing integration steps creates bizare behaviour
Replies: 1
Views: 21

Re: TWPL increasing integration steps creates bizare behaviour

Seb, I'm not sure what you want to simulate, but it seems you are simulating a sine-wave excitation of the beam. TWPL is not the element I'd choose for that. It's really intended for single-pass systems such as a deflector in a transport line. For a single-pass simulation, the results are pretty con...
by michael_borland
28 Jul 2022, 16:08
Forum: General
Topic: defining my own wiggler field
Replies: 6
Views: 67

Re: defining my own wiggler field

There are several ways to define undulator/wiggler fields in elegant, starting from field maps 1. CWIGGLER accepts data defining the undulator field in terms of longitudinal and transverse harmonics. 2. BGGEXP accepts data defining the fields in terms of generalized gradient expansions. 3. BMXYZ acc...
by michael_borland
27 Jul 2022, 20:15
Forum: General
Topic: Implementation of bunch lengthning and transverse impedance
Replies: 9
Views: 5150

Re: Implementation of bunch lengthning and transverse impedance

Sara,

At first blush, I guess it is because your 2-ps bin size is too large for a 6 ps rms bunch duration. Try 0.1 ps.

--Michael
by michael_borland
27 Jul 2022, 20:06
Forum: Optimization and Matching
Topic: orbit correction for a long beam line
Replies: 4
Views: 1775

Re: orbit correction for a long beam line

Esmaeil,

Can you upload your lattice file?

--Michael