  The dineutron as a bound chargeless nucleus of two identical nucleons has
been attracting attention for many decades. In addition to the study of the
formation of a bound dineutron in the outgoing channel of some specific nuclear
reactions, cross section estimates have been gaining interest as research
target. We used a traditional neutron activation technique to irradiate Lu
samples followed by measurements of the induced activity with HPGe spectrometer
in order to detect gamma-peaks of the ${}^{175}Lu (n, 2n)^{174g}Lu$ reaction
product when this reaction channel is not open for incident neutron energies.
Based on two measurements of the instrumental gamma ray spectra of Lu samples
we reliably identified the presence of the ${}^{174g}Lu$ isotope in the
outgoing channel of the ${}^{175}Lu(n, {}^2n)^{174g}Lu$ nuclear reaction. Also,
the cross section for this nuclear reaction was obtained and to be equal $33.5
\pm 5.9$ mb. For the first time, the dineutron as a nuclear reaction product
was indirectly detected via statistically significant observation of the
induced activity of ${}^{174g}Lu$ with corresponding cross-section estimate.
