  The spectrum averaged cross section (SACS) in standard neutron field is a
preferable tool for cross section validation. There are very few measurements
involving lutetium neutron cross sections. The presented work uses only neutron
standard, i.e., 252Cf(sf) neutron field, for validation of lutetium threshold
cross sections. SACS were inferred from gamma spectrometry derived reaction
rates. The SACS which were derived include 175Lu(n,2n)174Lu, 175Lu(n,3n)173Lu,
175Lu(n,p)175Yb, and 176Lu(n,n)176m1Lu reactions. All these reactions SACS were
measured for the first time. MCNP6 calculations using JEFF-3.3 or ENDF/B-VIII.0
libraries for lutetium cross sections were compared with experimental data. The
agreement was found very poor for all reactions under study. Thus there is a
need for their improvement. The presented data can be also used for validation
of the various theoretical models.
