https://repository.auw.edu.bd/handle/123456789/736 2026-07-25T03:09:15Z 2026-07-25T03:09:15Z Meaze, AKM Moinul Haque https://repository.auw.edu.bd/handle/123456789/929 2026-02-18T06:15:10Z 2014-01-01T00:00:00Z

Measurement and analysis of the 241Am(n,γ ) cross section with liquid scintillator detectors using time-of-flight spectroscopy at the n_TOF facility at CERN Meaze, AKM Moinul Haque The 241Am(n,γ ) cross section has been measured at the n_TOF facility at CERN using deuterated benzene liquid scintillators, commonly known as C6D6 detectors, and time-of-flight spectrometry. The results in the resolved resonance range bring new constraints to evaluations below 150 eV, and the energy upper limit was extended from 150 to 320 eV with a total of 172 new resonances not present in current evaluations. The thermal capture cross section was found to be σth = 678 ± 68 b, which is in good agreement with evaluations and most previous measurements. The capture cross section in the unresolved resonance region was extracted in the remaining energy range up to 150 keV, and found to be larger than current evaluations and previous measurements.

2014-01-01T00:00:00Z Meaze, AKM Moinul Haque https://repository.auw.edu.bd/handle/123456789/928 2026-02-18T06:14:58Z 2014-01-01T00:00:00Z

62Ni(n,γ ) and 63Ni(n,γ ) cross sections measured at the n_TOF facility at CERN Meaze, AKM Moinul Haque The cross section of the 62Ni(n,γ ) reaction was measured with the time-of-flight technique at the neutron time-of-flight facility n_TOF at CERN. Capture kernels of 42 resonances were analyzed up to 200 keV neutron energy and Maxwellian averaged cross sections (MACS) from kT = 5–100 keV were calculated. With a total uncertainty of 4.5%, the stellar cross section is in excellent agreement with the the KADoNiS compilation at kT = 30 keV, while being systematically lower up to a factor of 1.6 at higher stellar temperatures. The cross section of the 63Ni(n,γ ) reaction was measured for the first time at n_TOF. We determined unresolved cross sections from 10 to 270 keV with a systematic uncertainty of 17%. These results provide fundamental constraints on s-process production of heavier species, especially the production of Cu in massive stars, which serve as the dominant source of Cu in the solar system.

2014-01-01T00:00:00Z Meaze, AKM Moinul Haque https://repository.auw.edu.bd/handle/123456789/927 2026-02-18T06:15:19Z 2014-01-01T00:00:00Z

Experimental neutron capture data of 58Ni from the CERN n TOF facility Meaze, AKM Moinul Haque The 58Ni(n, γ) cross section has been measured at the neutron time of flight facility n TOF at CERN, in the energy range from 27 meV up to 400 keV. In total, 51 resonances have been analyzed up to 122 keV. Maxwellian averaged cross sections (MACS) have been calculated for stellar temperatures of kT = 5 − 100 keV with uncertainties of less than 6%, showing fair agreement with recent experimental and evaluated data up to kT = 50 keV. The MACS extracted in the present work at 30 keV is 34.2±0.6stat±1.8sys mb, in agreement with latest results and evaluations, but 12% lower relative to the recent KADoNIS compilation of astrophysical cross sections. When included in models of the s-process nucleosynthesis in massive stars, this change results in a 60% increase of the abundance of 58Ni, with a negligible propagation on heavier isotopes. The reason is that using both, the old or the new MACS, 58Ni is efficiently depleted by neutron captures.

2014-01-01T00:00:00Z