ax3l
commented
1 year ago @EZoni reported this was clarified during the developer meeting on Tuesday.
There was a misunderstanding between the mode number and the angle theta.
It was suggested that @RemiLehe might take some of the documentation from FBPIC over to WarpX to introduce RZ details in more depth than currently in our docs :)
With regard to external fields applied to particles, the documentation reports that "the position is defined in Cartesian coordinates, as a function of (x,y,z), even for RZ". If it is assumed that theta = 0 for the RZ domain, then one simply has (x,y,z) -> (r,theta,z), with which analytic external fields can be easily constructed. However, given that there was some subtlety regarding the y value of field probes in RZ, how the theta value of the RZ domain is being set should be clarified.