Different SW versions lead to very inconsistent results

[Shuo]

Dear Didier,

Thank you for the explanation. i have proceed with a test using the latest version of TraceWin.
The .dat file is as below:

Drift 0.00001 6
Drift 0.00001 6

Field_map 00700 2552.400 -50 3.162 0.0 1.0 0.0 0 3IBCs2_phase57b 1

Drift 0.00001 6
Drift 0.00001 6

END

The RF phase of the field card is -50° as you suggested.

And the final merged phase space at RFQ output is as below:

last_merged_output.png (771.88 KiB) Viewed 240 times

The result is a little different from before, but that's ok.

This problem is solved now, much thanks.

Best regards,

Shuo

[Shuo]

Dear Didier,

i did further testing today. When i changed the beam current from 2mA to 5mA, this issue appeared again.

5mA.png (216.79 KiB) Viewed 236 times

In addition, how to determine the RF phase of the RFQ field card? Why is it -50°? And could you plz provide me some references?

Best regards,

Shuo

[Didier]

Dear Shuo,

You should already understand that TraceWin is not designed to simulate an RFQ, and in fact we have a specific code for this type of structure, TOUTATIS, which is really designed for this purpose. Anyway, with TraceWin it's still possible via a field map, but TraceWin is not a time code like TOUTATIS is. This is a limitation that can generate approximations and, what's more, you'll have to adjust the RF phase to have a beam centred in phase at the output. With 5 mA I had to adjust the phase to -78 deg and the result is as follows.

output.png (255.05 KiB) Viewed 236 times

Regards,

Didier

[Shuo]

Dear Didier,

I appreciate the phase adjustment tip for working with the RFQ field map in TraceWin.
Your guidance is very valuable. I’ll take this into account in my simulations and adjust the RF phase accordingly.

Regards,

Shuo