Created attachment 35 [details] gzipped tar file of G4Sphere problem based on TestEm16 I have found that particles that are normally incident on a series of concentric large G4Spheres can jump to OutOfWorld, skipping over several volumes. I found the problem while working on a model of the atmosphere. It is mitigated by using a "Russian doll" geometry, but still occurs for shells placed as layers within the larger construct of the nestled G4Spheres. All physics is off. The problem does not occur when using G4Orbs. The problem does not seem to be material dependent or particle energy dependent. I have not tried a geantino. I created an example geometry from TestEm16, and have attached the gzipped tar file. I only had to modify DetectorCOnstruction.cc and PrimaryGeneratorAction.cc. Use /control/execute mytest.gmac and watch the tracking output. You should track to spherephys6, but it only gets to spherephys4, and does not see BoxPhys. Modify the detector geometry by commenting out the "BoxPhys" G4Sphere addition and see tracking occur normally. The SmallShellInnerRadius and SmallShellOuterRadius can be changed to larger values and the problem still occurs. This was originally discussed in the geometry section of the G4Hypernews sit as report #942.
*** Problem 1016 has been marked as a duplicate of this problem. ***
As it was mentioned by Vladimir Grichine(HyperNews, Geometry, #942), main problem in this aplication is the definition of solids with shared surfaces, even the World Volume has shared Theta Surface with other Solids. By making a few changes in given application, error disappears: 1. Introduce the WorldVolume(G4Box) that includes all your geometry without touching it. 2. Following Vladimir advice, in order to avoid shared surfaces,I have reduced the Spheres Daughters by very small value: ... G4Sphere *sphere= new G4Sphere(spherenum,ShellInnerRadius+0.1*i,ShellOuterRadius[i], 0.*deg,360*deg,0.*deg,(90.-0.001*i)*deg); ... //Added values are small in the rapport of the Sphere dimentions : 6600-7000 km Best Regards, Tatiana Nikitina
