分类: 物理学 >> 核物理学 提交时间: 2023-10-31
摘要: The 2H(d, p ) 3H bare nucleus astrophysical S(E) factor has been measured indirectly at energies from about 500 keV down to several keV by means of the Trojan-horse method applied to the quasi#2;free process 2H(6Li, pt)4He induced at the lithium beam energy of 11 and 9.5 MeV, which makes the virtual binary process incident energy Eqf dd go much closer to the zero-quasi-free-energy point than that in the previous similar experiment. The obtained results are compared with direct data as well as with previous indirect investigation of the same binary reactions. It shows that the precision of S(E) data in low energy range extracted via the same Trojan horse nucleus ( 6Li = ( d ) ) becomes better when the incident energy decreases from high value down to the zero-quasi-free-energy point. The very good agreement between data extracted from different Trojan horse nucleus ( 6Li = ( d ) vs. 3He = ( d p)) gives a strong updated test for the independence of the binary indirect cross section on the chosen Trojan horse nucleus at low energies.
分类: 物理学 >> 核物理学 提交时间: 2023-06-24
摘要: The multinucleon transfer (MNT) reaction is one promising way to produce neutron-rich heavy nuclei and even super heavynuclei and attracts more and more attentions theoretically and experimentally. A low energy nuclear structure spectrometer calledLENSHIAF specific to the MNT reactions will be designed and constructed in the ongoing big project HIAF in China. In theLENSHIAF spectrometer, the most challenge part is how to collect and stop efficiently the high-energy MNT products into the gascell. By using Monte-Carlo method, the geometry of the gas cell, the thickness of the titanium window/degrader, and the optimalgas pressure filled in the gas cell have been calculated and estimated. For neutron-rich nuclei around N=126 from 136Xe+198Ptreaction, with a titanium window/degrader with a thickness of 2.53.5 um, a cylindrical helium gas cell with a length of 0.6 m and adiameter of 1.2 m can satisfy the requirements to stop the target-like fragments. For heavier and super heavy nuclei from 238U+238Ureaction, with a 58 um thick titanium window/degrader, the cylindrical gas cell has to be as big as a length of at least 1.6 m and adiameter of 1.6 m.
分类: 物理学 >> 核物理学 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: In this study, the activation cross-sections were measured for 232Th(n,2n)231Th reactions at neutron energies of 14.1 and 14.8 MeV, which were produced by a neutron generator through a T(d,n)4He reaction. Induced gamma-ray activities were measured using a low background gamma ray spectrometer equipped with a high resolution HPGe detector. In the cross-section calculations, corrections were made regarding the effects of gamma-ray attenuation, dead-time, fluctuation of the neutron flux, and low energy neutrons. The measured cross-sections were compared with the literature data, evaluation data (ENDF-B/VII.1, JENDL-4.0 and CENDL-3.1), and the results of the model calculation (TALYS1.6).