CEA Codes forum

I would like to ask for a general question about how to proceed, not when we are designing an RFQ, but when we already have the RFQ 3D model, in a step file. The idea is to perform a benchmarking from previous beam dynamics performed with alternative codes. So, the question is from a 3D model, with the different dimensions, vane profile, etc, how can I construct the Tracewin RFQ commands?
I would realy appreciate your help in this issue.

Hi

This is a difficult task. One way to do it is to first build a . vane file from your step. You will need to write your own script for achieving this or use CAD reader equivalent features if there are any.

Even when your .vane file will be defined, you have to set up either a .inp file if you use Toutatis directly or .dat file if you use Tracewin. To do this, you will need to derive from your .vane file the number of cells, their length, average aperture radius R0, their pole tip radius, etc (see documentation for .inp file content or RFQCell in Tracewin).

An important point is that internal RFQ lengthes (from inner surfaces of entry and exit plates) in .vane file and .dat/.inp file must match. Once a .vane is used, Toutatis will only use the .vane file to mesh the geometry (R0 and rho at a certain z for each electrode).

Of course, on the top of this, you need to set up frequency, input energy etc.

There is unfortunately no supporting tool developed by CEA for doing what you are trying to achieve.

I hope it helps,

Romuald

Romuald,
thank you so much for your suggestions. We will take them into account!

I just thought about another approach that does not require Toutatis but TraceWin and a electrostatic solver that accepts step file for meshing.

Indeed, you could mesh your geometry and poloraize the vanes with the quadrupolar symetry. Once you got the electrostatic solution, export field map for TraceWin (see Tracewin manual for the format). After, you have to use the command FIELD_MAP in Tracewin but tells to the code that your field map is actually RF. I do not remember if the code will ask you a magnetic field map as well. In this case, set a map with the same structure and filled with zeroes.

I hope it helps.


Romuald

Dear RomualdDuperrier,
I used CST software to complete the RFQ model.
I refer to the TRACEWIn manual, but I still don't know how to export the field file for TraceWin.
Can you tell me the details of the format and how I should convert the CST exported field file?
I exported the grid used by the place as 25*25*121
In CST software, RFQ models are located at -3956 to 11
Chen

The next part of the post transferred to the TraceWin section, here : viewtopic.php?f=3&t=934