Can not determine decay channel for neutron

I have a simple geometry, an aluminum sphere of the thickness of 3 mm with Si detector inside it.
QBBC physics list is used and Geant4 10.5 p1 version.
Source particle is Al27 with spectrum bellow:

/gps/particle ion
/gps/ion 13 27
/gps/ene/type Arb
/gps/hist/type arb
/gps/hist/point 2.700000E+01 8.056426E-11
/gps/hist/point 2.970000E+01 9.837457E-11
/gps/hist/point 3.240000E+01 1.178625E-10
/gps/hist/point 3.780000E+01 1.617166E-10
/gps/hist/point 4.320000E+01 2.117936E-10
/gps/hist/point 4.860000E+01 2.678019E-10
/gps/hist/point 5.400000E+01 3.294400E-10
/gps/hist/point 5.940000E+01 3.964187E-10
/gps/hist/point 6.750000E+01 5.063368E-10
/gps/hist/point 7.560000E+01 6.268482E-10
/gps/hist/point 8.640000E+01 8.026518E-10
/gps/hist/point 9.450000E+01 9.449659E-10
/gps/hist/point 1.080000E+02 1.200227E-09
/gps/hist/point 1.215000E+02 1.475795E-09
/gps/hist/point 1.350000E+02 1.769596E-09
/gps/hist/point 1.485000E+02 2.079483E-09
/gps/hist/point 1.701000E+02 2.604506E-09
/gps/hist/point 1.917000E+02 3.160442E-09
/gps/hist/point 2.160000E+02 3.816407E-09
/gps/hist/point 2.430000E+02 4.576295E-09
/gps/hist/point 2.700000E+02 5.362447E-09
/gps/hist/point 2.970000E+02 6.169083E-09
/gps/hist/point 3.240000E+02 6.991803E-09
/gps/hist/point 3.780000E+02 8.670293E-09
/gps/hist/point 4.320000E+02 1.037379E-08
/gps/hist/point 4.860000E+02 1.208470E-08
/gps/hist/point 5.400000E+02 1.379033E-08
/gps/hist/point 5.940000E+02 1.548051E-08
/gps/hist/point 6.750000E+02 1.797117E-08
/gps/hist/point 7.560000E+02 2.039396E-08
/gps/hist/point 8.640000E+02 2.350163E-08
/gps/hist/point 9.450000E+02 2.573090E-08
/gps/hist/point 1.080000E+03 2.946688E-08
/gps/hist/point 1.215000E+03 3.340393E-08
/gps/hist/point 1.350000E+03 3.737364E-08
/gps/hist/point 1.485000E+03 4.098145E-08
/gps/hist/point 1.701000E+03 4.602810E-08
/gps/hist/point 1.917000E+03 5.061860E-08
/gps/hist/point 2.160000E+03 5.525936E-08
/gps/hist/point 2.430000E+03 5.975937E-08
/gps/hist/point 2.700000E+03 6.389120E-08
/gps/hist/point 2.970000E+03 6.754424E-08
/gps/hist/point 3.240000E+03 7.069463E-08
/gps/hist/point 3.780000E+03 7.517705E-08
/gps/hist/point 4.320000E+03 7.822440E-08
/gps/hist/point 4.860000E+03 8.054666E-08
/gps/hist/point 5.400000E+03 8.235622E-08
/gps/hist/point 5.940000E+03 8.352866E-08
/gps/hist/point 6.750000E+03 8.435427E-08
/gps/hist/point 7.560000E+03 8.409541E-08
/gps/hist/point 8.640000E+03 8.315293E-08
/gps/hist/point 9.450000E+03 8.216144E-08
/gps/hist/point 1.080000E+04 8.006663E-08
/gps/hist/point 1.215000E+04 7.749806E-08
/gps/hist/point 1.350000E+04 7.466937E-08
/gps/hist/point 1.485000E+04 7.179544E-08
/gps/hist/point 1.701000E+04 6.718233E-08
/gps/hist/point 1.917000E+04 6.268859E-08
/gps/hist/point 2.160000E+04 5.798626E-08
/gps/hist/point 2.430000E+04 5.308789E-08
/gps/hist/point 2.700000E+04 4.862934E-08
/gps/hist/point 2.970000E+04 4.463575E-08
/gps/hist/point 3.240000E+04 4.103297E-08
/gps/hist/point 3.780000E+04 3.489178E-08
/gps/hist/point 4.320000E+04 2.991550E-08
/gps/hist/point 4.860000E+04 2.587164E-08
/gps/hist/point 5.400000E+04 2.255915E-08
/gps/hist/point 5.940000E+04 1.982345E-08
/gps/hist/point 6.750000E+04 1.655871E-08
/gps/hist/point 7.560000E+04 1.405674E-08
/gps/hist/point 8.640000E+04 1.163156E-08
/gps/hist/point 9.450000E+04 1.021269E-08
/gps/hist/point 1.080000E+05 8.227077E-09
/gps/hist/point 1.215000E+05 6.689205E-09
/gps/hist/point 1.350000E+05 5.483461E-09
/gps/hist/point 1.485000E+05 4.537968E-09
/gps/hist/point 1.701000E+05 3.429991E-09
/gps/hist/point 1.917000E+05 2.649494E-09
/gps/hist/point 2.160000E+05 2.025950E-09
/gps/hist/point 2.430000E+05 1.542522E-09
/gps/hist/point 2.700000E+05 1.201433E-09
/gps/hist/point 2.970000E+05 9.545918E-10
/gps/hist/point 3.240000E+05 7.708714E-10
/gps/hist/point 3.780000E+05 5.247968E-10
/gps/hist/point 4.320000E+05 3.742768E-10
/gps/hist/point 4.860000E+05 2.768246E-10
/gps/hist/point 5.400000E+05 2.108511E-10
/gps/hist/point 8.100000E+05 7.267635E-11
/gps/hist/point 1.080000E+06 3.373568E-11
/gps/hist/point 1.350000E+06 1.850901E-11
/gps/hist/point 1.620000E+06 1.130370E-11
/gps/hist/point 1.890000E+06 7.438663E-12
/gps/hist/point 2.160000E+06 5.171815E-12
/gps/hist/point 2.430000E+06 3.750810E-12
/gps/hist/point 2.700000E+06 2.812731E-12
/gps/hist/inter Lin
/gps/ang/type cos
/gps/ang/mintheta 0.000E+00 deg
/gps/ang/maxtheta 9.000E+01 deg

/control/alias NORM_FACTOR_SPECTRUM " 1.463051E+04 "
/control/alias NORM_FACTOR_ANGULAR " 2.500000E-01 "

Unfortunately, the exception occurs as follow:

-------- WWWW -------- G4Exception-END --------- WWWW -------

G4DecayTable::SelectADecayChannel :: no possible DecayChannel neutron

-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : DECAY003
issued by : G4Decay::DoIt
Can not determine decay channel for neutron
mass of dynamic particle: 0.930611 (GEV)
dacay table has 1 entries
0: BR 1, IsOK? 0, --> e- + anti_nu_e + proton

*** Fatal Exception *** core dump ***
G4Track (058EE8A0) - track ID = 296, parent ID = 1
Particle type : neutron - creator process : ionInelastic, creator model : Binary Cascade
Kinetic energy : 0 eV - Momentum direction : (1,0,0)
Step length : 0 fm - total energy deposit : 0 eV
Pre-step point : (-17.813,23.3866,35.7244) - Physical volume : shield (G4_Al)

  • defined by : not available
    Post-step point : (-17.813,23.3866,35.7244) - Physical volume : shield (G4_Al)
  • defined by : not available
    *** Note: Step information might not be properly updated.

-------- EEEE -------- G4Exception-END --------- EEEE -------

Is there any solution to this problem besides

Thank you,


it is a known problem which we have fixed only recentlyand the fix will be available in Geant4 10.6 (December,6).


Thank you for very quick answer.
Best regards,


Are you going to patch Geant4 10.5, too? We've encountered a similar problem when we use Geant4 10.5.