CEA Codes forum

I'm having trouble calculating the beam acceptance of a beam along a cavity. From an initial distribution, I run the simulation and I get the output phase space, with which I calculate the acceptance with PlotWin from the method explained in the Manual (Acceptance calculation using TraceWin and PlotWin).
However, when I use this distribution as input, the beam is not transmitted well through the same cavity, when it should be transmitted without losses. I think there is a problem with the longitudinal definition of the beam.

I have also tried to verify the simulations with the backtrack feature, but I am not able to perform the backtrack simulation.

Dear Pedro,

I agree in principle, but could you send me your example, simplified as much as possible?

Regards,

Didier

Thank you for your fast answer.

I think I understood where the issue came from, thanks to your comment that the space-charge cannot be taken into account when calculating the acpetance. Indeed, when I eliminate the space-charge forces by setting the current to zero, the acceptance is calculated correctly.

Dear Pedro,

Yes, you would understand, I think, that applying the space charge to the distribution used to calculate acceptance doesn't make much physical sense.

Regards,

Didier