Measurement of isomeric yield ratios for ~(93)Nb(γ,4n) ~(89m,g)Nb and ~(nat)Mo(γ,xn1p)~(95m,g)Nb reactions with 50-, 60-, and 70-MeV bremsstrahlung

摘要

We measured the isomeric yield ratios for the photonuclear reactions of ~(93)Nb(γ,4n)~(89m),gNb and ~(nat)Mo(γ,xnp) ~(95m,g)Nb by using the activation method. The high-purity ~(93)Nb and natMo metallic foils in disc shape were irradiated with uncollimated bremsstrahlung beams of 50-, 60-, and 70-MeV generated from an electron linear accelerator in Pohang Accelerator Laboratory. The induced activities in the irradiated foils were measured by the high-resolution γ-ray spectrometry with a calibrated high-purity Germanium (HPGe) detector coupled to a PC-based 4 K multichannel analyzer. The reaction ~(93)Nb(γ,4n)~(89m,g)Nb was studied for the first time which has no comparable literature data. The result of ~(95m,g)Nb isomeric pair was measured based on (γ,p), (γ,np), and (γ,2np) reactions which is the first measurement at the intermediate energy region of 50-70-MeV with a ~(nat)Mo target.