Measurement of 232Th and 238U neutron capture cross-sections in the energy range 5-17 MeV

The neutron capture cross sections of ²³²Th and ²³⁸U at the average neutron energies of 5.08 ± 0.17, 8.96 ± 0.77, 12.47 ± 0.83, and 16.63 ± 0.95 MeV have been measured by using the activation technique and off-line γ-ray spectroscopy. The ²³²Th and ²³⁸U were irradiated with neutrons produced from the ⁷Li(p, n) reaction using the proton energies of 7, 11, 15 and 18.8 MeV from the 14UD BARC-TIFR Pelletron facility in Mumbai, India. Detailed covariance analysis was also performed to evaluate the uncertainties in the measured cross-sections. The excitation function of the ²³²Th(n, γ) and ²³⁸U(n, γ) reactions were calculated using the theoretical model code TALYS-1.9. The experimental and theoretical results from the present work were compared with the ENDF/B-VII-1 and JENDL-4.0 nuclear data libraries and were found to be in good agreement.

Investigation of (n, p), (n, 2n) reaction cross sections for Sn isotopes for fusion reactor applications

The compound Nb₃Sn possess superconductivity at suitable temperatures, therefore, it is best suited to be used in the toroidal coils of superconducting magnets which holds the fusion plasma and confine it inside the reactor core. The neutron induced reaction cross-sections are required from threshold to 20MeV for different isotopes of Tin (Sn). Since limited data is available for the reactions with the Sn isotopes. Therefore, we have optimized the (n, p) and (n, 2n) reaction cross-sections for all possible Sn isotopes from threshold to 20MeV with modified input parameters in the nuclear reaction modular codes EMPIRE-3.2.2 and TALYS-1.8. These codes account for the major nuclear reaction mechanisms, including direct, pre-equilibrium, and compound nucleus contributions. The present results from ¹¹⁶Sn(n,p)^116mIn, , ¹¹⁷Sn(n,p)^117mIn, ¹¹⁸Sn(n,2n)^117mSn,¹²⁰Sn(n,2n)^119mSn and ¹²⁴Sn(n,2n)^123mSn reactions calculated with nuclear modular codes: TALYS - 1.8, EMPIRE - 3.2.2 were compared with EXFOR data, systematics proposed by several authors and with the existing evaluated nuclear data library ENDF/B-VII.1, as well. The results from the present study can be used for the future development of ITER devices as well as to upgrade the nuclear model codes.

Measurement of formation cross-section of 99Mo from the 98Mo(n,γ) and 100Mo(n,2n) reactions

The formation cross-section of medical isotope ⁹⁹Mo from the ⁹⁸Mo(n,γ) reaction at the neutron energy of 0.025eV and from the ¹⁰⁰Mo(n,2n) reaction at the neutron energies of 11.9 and 15.75MeV have been determined by using activation and off-line γ-ray spectrometric technique. The thermal neutron energy of 0.025eV was used from the reactor critical facility at BARC, Mumbai, whereas the average neutron energies of 11.9 and 15.75MeV were generated using ⁷Li(p,n) reaction in the Pelletron facility at TIFR, Mumbai. The experimentally determined cross-sections were compared with the evaluated nuclear data libraries of ENDF/B-VII.1, CENDL-3.1, JENDL-4.0 and JEFF-3.2 and are found to be in close agreement. The ¹⁰⁰Mo(n,2n)⁹⁹Mo reaction cross-sections were also calculated theoretically by using TALYS-1.8 and EMPIRE-3.2 computer codes and compared with the experimental data.

Determination of 55Mn(n,γ)56Mn reaction cross-section at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV

The 55Mn(n,γ)56Mn reaction cross-sections at the neutron energies of 1.12, 2.12, 3.12 and 4.12 MeV were determined by using activation and off-line γ-ray spectrometric technique. The neutron energies of 1.12 and 2.12 MeV were generated from the 7Li(p,n) reaction by using the proton energies of 3 and 4 MeV from the folded tandem ion beam accelerator (FOTIA) at BARC. For the neutron energies of 3.12 and 4.12 MeV, the proton energies used were 5 and 6 MeV from the Pelletron facility at TIFR, Mumbai. The 115In(n,γ)116mIn reaction cross-section was used as the neutron flux monitor. The 55Mn(n,γ)56Mn reaction cross-section at the neutron energies of 4.12 MeV are reported for the first time, whereas at 1.12, 2.12 and 3.12 MeV, they are in between the literature data. The 55Mn(n,γ)56Mn reaction cross-section was also calculated theoretically by using the computer code TALYS 1.6 and EMPIRE 3.2.2. The experimental data of present work are found to be in between the theoretical values of TALYS and EMPIRE.