Figure 1 shows the maximum percentage difference in the damage functions obtained with NJOY-2021 (version 1.2.2) with respect NJOY-2016 (version 65) when ENDF/B.VIII.0 cross section library is employed.

*Figure 1. Maximum percentage difference of damage function obtained with NJOY-2021 with respect NJOY-2016 as a function of the target element using both Robinson (solid red line) and Akkermann (dashed black line) partition functions. ENDF/B.VIII.0 cross section library is employed.*

For almost all target elements there is no difference in the values obtained with NJOY-2021 with respect NJOY-2016, only for Oxigen there is a negligible difference.

Differences in damage function arise when ENDF/B.VIII.0 or ENDF/B.VII.1 cross section library are employed.

The following figures show the percentage difference in the neutron NIEL dose employing NJOY-2021 using ENDF/B.VIII.0 cross section library with respect NJOY-2016 using ENDF/B.VII.1 cross section library. The reactor spectral fluences are those of ITN-ΣΣ (from [Angelescu et al. (1994)]), IPEN/MB-01 (from [Bitelli et al. (2009)]), TRIGA-Vienna (from [Cagnazzo (2014)]), TRIGA ENEA Casaccia and TAPIRO ENEA Casaccia. TRIGA ENEA spectrum is measured at 100 kW in the Lazy Susan channel. TAPIRO ENEA spectrum is measured at 4 kW in the Radial channel 1.

*Figure 2. NIEL Dose percentage difference for ITN-ΣΣ (from [Angelescu et al. (1994)]) spectral fluence as a function of target elements for NJOY-2021 using ENDF/B.VIII.0 cross section library with respect NJOY-2016 using ENDF/B.VII.1 cross section library. The analysis is performed for both Robinson (solid red line) and Akkermann (dashed black line) partition function.*

*Figure 3. NIEL Dose percentage difference for IPEN/MB-01 (from [Bitelli et al. (2009)]) spectral fluence as a function of target elements for NJOY-2021 using ENDF/B.VIII.0 cross section library with respect NJOY-2016 using ENDF/B.VII.1 cross section library. The analysis is performed for both Robinson (solid red line) and Akkermann (dashed black line) partition function.*

*Figure 4. NIEL Dose percentage difference for TRIGA-Vienna (from [Cagnazzo (2014)]) spectral fluence as a function of target elements for NJOY-2021 using ENDF/B.VIII.0 cross section library with respect NJOY-2016 using ENDF/B.VII.1 cross section library. The analysis is performed for both Robinson (solid red line) and Akkermann (dashed black line) partition function.*

*Figure 5. NIEL Dose percentage difference for TRIGA ENEA Casaccia spectral fluence as a function of target elements for NJOY-2021 using ENDF/B.VIII.0 cross section library with respect NJOY-2016 using ENDF/B.VII.1 cross section library. The analysis is performed for both Robinson (solid red line) and Akkermann (dashed black line) partition function.*

*Figure 6. NIEL Dose percentage difference for TAPIRO ENEA Casaccia spectral fluence as a function of target elements for NJOY-2021 using ENDF/B.VIII.0 cross section library with respect NJOY-2016 using ENDF/B.VII.1 cross section library. The analysis is performed for both Robinson (solid red line) and Akkermann (dashed black line) partition function.*

### References

T. Angelescu et al., Nucl. Instr. and Meth. in Phys. Res., vol. 345, 2, pp. 303-307, 1994

U. Bitelli and F.P. Martins, Brazilian Journal of Physics, vol. 39, pp. 39-43, 2009

M. Cagnazzo et al., 23rd International Conference Nuclear Energy for New Europe, 2014