I posted this error to the hadronic process list, Hans-Peter recommended I submit a bug report. The simulation is of a thin (276nm) layer of boron carbide on a silicon substrate. The detector is used to count thermal neutron flux. The kinematics of my secondaries seems strange. The primary reaction of interest is B_10 + n0 -> Li7 + Alpha +gamma. In EVERY reaction, both the Lithium and Alpha strike the next layer of the detector. Shouldn't they be close to back to back? Sometimes all three strike the Silicon layer. If you need more information, I'll be happy to provide. clundst@unlserve.unl.edu enc: A typical event: ********************************************************************************************************* * G4Track Information: Particle = neutron, Track ID = 1, Parent ID = 0 ********************************************************************************************************* Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 20 0 0 1e-09 0 0 0 expHall initStep 1 17.8 0 0 1e-09 0 2.2 2.2 b4clayerPhys Transportation 2 17.8 0 0 1e-09 0 0.0201 2.22 b4clayerPhys inelastic ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 4, Parent ID = 1 ********************************************************************************************************* Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 17.8 0 0 0.478 0 0 0 b4clayerPhys initStep 1 17.8 0.000168 0.000276 0.478 0 0.000417 0.000417 SiLayer Transportation 2 17.8 0.0126 0.0208 0.478 0 0.031 0.0314 expHall Transportation 3 20 1.41 2.33 0.478 0 3.48 3.51 OutOfWorld Transportation ********************************************************************************************************* * G4Track Information: Particle = Li7[0.0], Track ID = 3, Parent ID = 1 ********************************************************************************************************* Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 17.8 0 0 0.832 0 0 0 b4clayerPhys initStep 1 17.8 -2.11e-05 -0.000276 0.665 0.166 0.000277 0.000277 SiLayer Transportation 2 17.8 -3.68e-05 -0.000425 0.606 0.059 0.00015 0.000427 SiLayer msc 3 17.8 -5.27e-05 -0.000574 0.55 0.056 0.00015 0.000576 SiLayer msc 4 17.8 -6.58e-05 -0.000723 0.492 0.0585 0.00015 0.000726 SiLayer msc 5 17.8 -8.34e-05 -0.000872 0.437 0.0545 0.00015 0.000876 SiLayer msc 6 17.8 -0.000103 -0.00102 0.387 0.0499 0.00015 0.00103 SiLayer msc 7 17.8 5.32e-05 -0.00166 0.18 0.207 0.000613 0.00164 SiLayer hLowEIoni 8 17.8 6.52e-05 -0.00231 0.034 0.146 0.000712 0.00235 SiLayer hLowEIoni 9 17.8 0.000277 -0.00287 0 0.034 0.000656 0.00301 SiLayer hLowEIoni ********************************************************************************************************* * G4Track Information: Particle = alpha, Track ID = 2, Parent ID = 1 ********************************************************************************************************* Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 17.8 0 0 1.45 0 0 0 b4clayerPhys initStep 1 17.8 2.07e-05 0.000276 1.42 0.0252 0.000277 0.000277 SiLayer Transportation 2 17.8 6.65e-05 0.00106 1.37 0.0511 0.000785 0.00106 SiLayer msc 3 17.8 0.000106 0.00184 1.32 0.0542 0.000785 0.00185 SiLayer msc 4 17.8 0.00015 0.00263 1.26 0.0557 0.000785 0.00263 SiLayer msc 5 17.8 0.000208 0.00341 1.21 0.0567 0.000785 0.00342 SiLayer msc 6 17.8 0.000249 0.00419 1.14 0.0623 0.000785 0.0042 SiLayer msc 7 17.8 0.000296 0.00514 1.07 0.0788 0.000949 0.00515 SiLayer hLowEIoni 8 17.8 0.000352 0.00609 0.985 0.0796 0.000949 0.0061 SiLayer hLowEIoni 9 17.8 0.000409 0.00704 0.902 0.0834 0.000949 0.00705 SiLayer hLowEIoni 10 17.8 0.000451 0.00798 0.819 0.0831 0.000949 0.008 SiLayer hLowEIoni 11 17.8 0.000453 0.00893 0.73 0.0889 0.000949 0.00895 SiLayer hLowEIoni 12 17.8 0.00047 0.00988 0.64 0.0896 0.000949 0.0099 SiLayer hLowEIoni 13 17.8 0.000527 0.0108 0.539 0.101 0.000949 0.0108 SiLayer hLowEIoni 14 17.8 0.00059 0.0118 0.437 0.102 0.000949 0.0118 SiLayer hLowEIoni 15 17.8 0.000675 0.0127 0.326 0.112 0.000949 0.0127 SiLayer hLowEIoni 16 17.8 0.00074 0.0136 0.207 0.118 0.000949 0.0137 SiLayer hLowEIoni 17 17.8 0.0063 0.0157 0.0911 0.116 0.000949 0.0146 SiLayer hLowEIoni 18 17.8 0.00623 0.0164 0.0123 0.0788 0.000949 0.0156 SiLayer hLowEIoni 19 17.8 0.0064 0.0167 0 0.0123 0.000546 0.0161 SiLayer hLowEIoni
I did run a set of reactions with 10^-10MeV neutron into B. The result is below. The numbers after "SECONDARIES info" are total energy, and 3-momentum. As you see, the fragments come out essentially back-to-back. May be you can put your application someplace, where I can find it, and I'll have a closer look. Many greetings, Hans-Peter. Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(-2.570862e+01,6.699680e+01,-7.519707e+01)3 SECONDARIES info6.534667e+03(2.595904e+01,-6.691105e+01,7.560655e+01)0 SECONDARIES info4.775995e-01(-2.579513e-01,-8.036663e-02,-3.938320e-01)-3 QVALUE = 2.758158e+00 Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(3.045075e+01,5.231214e+01,8.450027e+01)3 SECONDARIES info6.534655e+03(-3.019973e+01,-5.219066e+01,-8.410274e+01)0 SECONDARIES info4.775996e-01(-2.405916e-01,-1.035754e-01,-3.993611e-01)-3 QVALUE = 2.746057e+00 Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(5.870308e+01,7.327475e+01,-4.459672e+01)3 SECONDARIES info6.534659e+03(-5.870543e+01,-7.284930e+01,4.486167e+01)0 SECONDARIES info4.775989e-01(8.899067e-03,-4.089418e-01,-2.465525e-01)-3 QVALUE = 2.750400e+00 Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(4.476266e+01,-9.281023e+01,-1.366277e+01)3 SECONDARIES info6.534658e+03(-4.460716e+01,9.269016e+01,1.320569e+01)0 SECONDARIES info4.775991e-01(-1.631135e-01,9.763042e-02,4.381360e-01)-3 QVALUE = 2.749615e+00 Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(-6.070129e+01,4.966587e+01,-6.821115e+01)3 SECONDARIES info6.534658e+03(6.072128e+01,-4.982315e+01,6.774538e+01)0 SECONDARIES info4.775993e-01(-1.344920e-02,1.558518e-01,4.512543e-01)-3 QVALUE = 2.749860e+00 Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(1.022882e+01,-1.013865e+02,-2.049985e+01)3 SECONDARIES info6.534655e+03(-1.002068e+01,1.009540e+02,2.046022e+01)0 SECONDARIES info4.775999e-01(-2.208317e-01,4.232616e-01,1.358680e-02)-3 QVALUE = 2.746179e+00 Last chance before DoIt call: NUMBER OF SECONDARIES=3FINAL STATE = 1.000000e-10 (0.000000e+00,0.000000e+00,1.000000e+00) SECONDARIES info3.728866e+03(-7.864378e+01,3.812353e+01,5.626590e+01)3 SECONDARIES info6.534656e+03(7.855544e+01,-3.793079e+01,-5.585317e+01)0 SECONDARIES info4.776006e-01(9.472475e-02,-1.921710e-01,-4.268488e-01)-3 QVALUE = 2.747597e+00
Hi Carl, I have your aoolication running, and used the new tool for checking the geometry. It is just a on-line command: /geometry/test/recursive_test which looks for overlaps in the geometrical description. It tells me that there are overlaps between the silicon and the BC layers. Most of the parameters of the geant4 solids are actually half-sizes, not sizes, so may be there was some confusion. Please use the geometry-checking, and sort out the overlaps. If you then still have problems, please let me know. Many greetings, Hans-Peter. /geometry/test/recursive_test
