RFQ .vane file modification
Posted: Wed 9 Sep 2026 10:11
Dear Didier,
I modified the .vane file of my RFQ to simulate a deformation. It seems that the file is being read correctly by TraceWin. I then wanted to investigate the impact of this deformation in order to evaluate its effect on the transmission.
The files toutatis_0.61_mm.vane and toutatis_0.62_mm.vane appear to show no degradation of the RFQ transmission compared with toutatis_nominal.vane, which corresponds to the ideal geometry.
However, with the file toutatis_0.63_mm.vane, which contains a slightly larger deformation, the transmission suddenly drops by about 40%. Then, for much larger deformations such as toutatis_0.7_mm.vane and toutatis_0.8_mm.vane, the transmission remains almost unchanged from 0.63 mm. This behaviour seems somewhat unusual to me. In addition, I noticed that starting from 0.63 mm and above, I obtain a warning message related to the mesh generation when the particle tracking starts.
This raises two questions for me:
- Am I applying the deformation correctly ? I am applying it both to the vane coordinate columns and to the centroid columns. By modifying both, could I actually be cancelling out the deformation ? If so, would that explain why I do not observe any significant difference in transmission for the 0.61 mm and 0.62 mm cases ?
- Can the mesh warning message be safely ignored, or is it indicative of a real issue that could affect the transmission calculation ? Given that the sudden drop in transmission appears exactly when this warning starts to occur, I am wondering whether the observed loss of transmission might be related to a numerical or meshing problem rather than a physical effect of the deformation.
On another topic, I have the impression that I can no longer modify the particle mass to an arbitrary value, nor can I select a negative charge when clicking on the yellow arrow next to the particle type name.
Thank you in advance for your help.
I modified the .vane file of my RFQ to simulate a deformation. It seems that the file is being read correctly by TraceWin. I then wanted to investigate the impact of this deformation in order to evaluate its effect on the transmission.
The files toutatis_0.61_mm.vane and toutatis_0.62_mm.vane appear to show no degradation of the RFQ transmission compared with toutatis_nominal.vane, which corresponds to the ideal geometry.
However, with the file toutatis_0.63_mm.vane, which contains a slightly larger deformation, the transmission suddenly drops by about 40%. Then, for much larger deformations such as toutatis_0.7_mm.vane and toutatis_0.8_mm.vane, the transmission remains almost unchanged from 0.63 mm. This behaviour seems somewhat unusual to me. In addition, I noticed that starting from 0.63 mm and above, I obtain a warning message related to the mesh generation when the particle tracking starts.
- error_message.png (11.27 KiB) Viewed 45 times
This raises two questions for me:
- Am I applying the deformation correctly ? I am applying it both to the vane coordinate columns and to the centroid columns. By modifying both, could I actually be cancelling out the deformation ? If so, would that explain why I do not observe any significant difference in transmission for the 0.61 mm and 0.62 mm cases ?
- Can the mesh warning message be safely ignored, or is it indicative of a real issue that could affect the transmission calculation ? Given that the sudden drop in transmission appears exactly when this warning starts to occur, I am wondering whether the observed loss of transmission might be related to a numerical or meshing problem rather than a physical effect of the deformation.
On another topic, I have the impression that I can no longer modify the particle mass to an arbitrary value, nor can I select a negative charge when clicking on the yellow arrow next to the particle type name.
Thank you in advance for your help.