Measurement and estimation of isomeric cross section of 137Ba(n, n′)137mBa reaction using accelerator based neutron source

Cross sections for formation of 139mCe radioisotope through the 140Ce (n, 2n) reaction over 13.73-14.77 MeV neutrons

Cross sections for the formation of metastable state of ¹³⁹Ce through ¹⁴⁰Ce(n, 2n)^139mCe reaction were measured at five neutron energies over 13.73-14.77 MeV range using the activation method and off-line gamma-ray spectrometric technique. These cross sections were in agreement with the corresponding theoretical cross sections estimated over 10-20 MeV neutrons by EMPIRE-3.2 code, using LEVEDEN 4 and strength function GSTRFN 0 parameters, and TALYS-1.8 code using ldmodel 5 and preeqmode 4 parameters. The estimated most probable excitation energies of ¹³⁹Ce were 1.320-3.877 MeV, respectively over 13.73 MeV and 14.77 MeV neutron energies.