tokens: ( b ) Otherwise , by applying radiation simulation tools agreed with the customer . NOTE 1 Examples of such tools are Geant4 , MCNPX , and FLUKA . More examples can be found in Table 2 of ECSS - E - HB-10 - 12 . NOTE 2 For a rational and detailed discussion on energy deposition spectrum from direct ionization calculation and nucleon - nuclear interactions , see ECSS - E - HB-10 - 12 , Section 9.2 .