Experimental validation of the neutron flux suppression in samples with high manganese content in instrumental neutron activation analysis

Instrumental neutron activation analysis (INAA) relies on constant neutron flux densities throughout the activated samples. Although this concept is true for most typical samples, occasionally, the presence of highly neutron absorbing nuclides in the sample may cause a neutron flux density suppression which would ultimately lead to distorted results in the INAA. Here, we have investigated artificial samples with a high manganese (Mn) content. By adding aqueous gold solution, we introduced a liquid in-situ neutron flux monitor into the sample. An Mn content ≤ 50% shows little effect to the internal neutron flux density, however, the flux can be suppressed by ca. 20% when the Mn content reaches 63.2%.