Am-Be neutron irradiator used for nuclear instrumentation training

A neutron irradiator was assembled at IPEN (Nuclear and Energy Research Institute) facility to perform qualitative-quantitative analysis of materials, using thermal and fast neutrons. In order to determine the
^116m
In decay constant, a thermal flux obtained experimentally by Monte Carlo N-Particle Transport Code-MCNP, in a previous work, was used in the nuclear experiment. The activity calculated from the activation parameters was 13.51±0.17 kBq and the activity determined experimentally was 12.51± 0.36 kBq. The decay constant determined by the pulse height analyzer (PHA) measures was 211.4 µ·s
⁻¹
, and that determined by fitting the data using a Multichannel Scaler (MCS) system was 200.3 ± 1.6 µ·s
⁻¹
. The half-life of
^116m
In found in the literature is 3256.8 s, which corresponds to a decay constant of 212.8 µ·s
⁻¹
. The present experiment does not intend to establish a new value for the decay constant: it solely aims students' practical exercises in nuclear properties of elements. This experiment is part of the nuclear experimental course.