[Archive] Particle not in the right tetrahedron?

Message by engwall:

Hello everybody,

When running a simulation with a flowing plasma and fixed spacecraft potential, everything looks fine for almost 600 time-steps, when the simulation suddenly crashes with the following error notes:

>>>>>> Exception raised in task <JyTop> 
>>>>>> BEGIN TASK EXCEPTION HANDLING 
Traceback (most recent call last): 
File "/usr/home/erike/Spis3.00.01rc1/SpisUI/../SpisUI/Bin/Tasks/TaskJyTop.py", line 71, in run_task caller.Run() 
File "/usr/home/erike/Spis3.00.01rc1/SpisUI/./Bin/SpisNumCaller.py", line 69, in Run sharedSolver['jytop'].Run() 
File "/usr/home/erike/Spis3.00.01rc1/SpisUI/./Bin/JyTop4.py", line 458, in Run self.simu.integrate() 
spis.Util.Exception.SpisRuntimeException: spis.Util.Exception.SpisRuntimeException: advance: particle not in the right tetrahedron
>>>>>> END TASK EXCEPTION HANDLING 
task JyTop just terminate 

Does anybody have a clue about what has gone wrong?
See you!
Erik

Message by thiebault:

Hi Erik, I know it’s a little too late for the SPINE meeting, but here is a trick : this seems to happen when a particle crosses more than one tetrahedron in one time step… To prevent this from happening, you can either use larger mesh elements (sometimes, it also happens when you have very thin and long triangles… so beware of the shape of your triangles), or simply decrease the time step… Of course, when you model PIC electrons (and/or photoelectrons… and if you have strong electric fields) with a very thin mesh, you have to go very low… and the simulation is longer… but it works ! See you Ben