Photodisintegration Cross Section Measurements for $^{142}$Nd and $^{150}$Nd and Low-energy E1 $\gamma$-ray Strength Functions

The photo-neutron disintegration cross sections were measured near threshold for $^{142}$Nd, and, for the first time, $^{150}$Nd. The measurements were made using the monoenergetic $\gamma$-ray beam at the AIST TERAS facility in Tsukuba, Japan. The $\gamma$-ray beam was produced via laser inverse-Compton scattering. The neutrons were detected using a composite detector consisting of $^{3}$He proportional counters embedded in a polyethylene block. The technique and facility will be overviewed, highlighting the advantages of a monoenergetic $\gamma$-ray beam to absolute cross section measurements. The results will be compared to theoretical calculations using the Quasi-particle Random Phase Approximation (QRPA). Finally, the neutron number dependence of the low-energy E1 $\gamma$-ray strength function will be discussed.