分类: 核科学技术 >> 辐射物理与技术 提交时间: 2024-04-29
摘要: One-neutron stripping process between 6Li and 209Bi was studied at 28, 30, and 34 MeV using the in-beam γ-ray spectroscopy method. The γ-γ coincident analysis clearly identified two γ-rays feeding the ground and long-lived isomeric states, which were employed to determine the cross section. The one-neutron stripping cross sections were similar to the cross sections of complete fusion in the 6Li+209Bi system, but the one-neutron stripping cross sections decreased more gradually at the sub-barrier region. A coupled-reaction-channel calculation was performed to study the detailed reaction mechanism of the one-neutron stripping process in 6Li. The calculations indicated that the first excited state of 5Li is critical in the actual one-neutron transfer mechanism, and the valence proton of 209Bi can be excited to the low-lying excited state in (6Li, 5Li) reaction, unlike in the (d,p) reaction.
分类: 天文学 >> 天文学 提交时间: 2023-02-19
摘要: Flux densities are basic observation parameters to describe pulsars. In the most updated pulsar catalog, 24% of the listed radio pulsars have no flux density measurement at any frequency. Here, we report the first flux density measurements, spectral indices, pulse profiles, and correlations of the spectral index with pulsar parameters for 19 pulsars employing the Ultra-Wideband Low (UWL) receiver system installed on the Parkes radio telescope. The results for spectral indices of 17 pulsars are in the range between -0.6 and -3.10. The polarization profiles of thirteen pulsars are shown. There is a moderate correlation between the spectral index and spin frequency. For most pulsars detected, the S/N ratio of pulse profile is not high, so DM, Faraday rotation measure (RM), and polarization can not be determined precisely. Twenty-nine pulsars were not detected in our observations. We discuss the possible explanations for why these pulsars were not detected.