Four key reactions, 12C(, )13O, 13C(, n)16O, 25Mg(p, )26Al and 19F(p, )16O, will be studied for the first time within or near the astrophysical relevant energy regions (Gamow window) at Jinping Underground laboratory ...Four key reactions, 12C(, )13O, 13C(, n)16O, 25Mg(p, )26Al and 19F(p, )16O, will be studied for the first time within or near the astrophysical relevant energy regions (Gamow window) at Jinping Underground laboratory for Nuclear Astrophysics (JUNA)[1], which will take the advantage of the ultra-low background of China JinPing underground Laboratory (CJPL), high current accelerator based on ECR source and a highly sensitive detection system.展开更多
To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produce...To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produced by the tandem-accelerator in the China Institute of Atomic Energy was utilized.The proton beam was first transmitted through a 60.5μm aluminum foil and then impinged on a natural LiF target to produce neutron beam via^(7)Li(p,n)7Be reaction.The quasi-Gaussian energy distribution of protons in the LiF target resulted in neutron energy spectra that agreed with a Maxwellian energy distribution at kT=(22±2)keV,which was achieved by integrating neutrons detected within an emission angle of 65.0°±2.6°using a ^(6)Li glass detector positioned at 65°relative to the proton beam direction.The narrow angular spread of the Maxwelliandistributed neutron beam enables direct measurement of neutron capture cross-sections for most s-process nuclides,overcoming previous experimental limitations associated with broad angular distributions.展开更多
文摘Four key reactions, 12C(, )13O, 13C(, n)16O, 25Mg(p, )26Al and 19F(p, )16O, will be studied for the first time within or near the astrophysical relevant energy regions (Gamow window) at Jinping Underground laboratory for Nuclear Astrophysics (JUNA)[1], which will take the advantage of the ultra-low background of China JinPing underground Laboratory (CJPL), high current accelerator based on ECR source and a highly sensitive detection system.
基金National Natural Science Foundation of China(12125509,11961141003,12275361,U2267205,12175152,12175121)National Key Research and Development Project(2022YFA1602301)Continuous-support Basic Scientific Research Project。
文摘To generate a neutron beam exhibiting a Maxwellian energy distribution with narrow emission angles for measuring the neutron capture reaction rates of the s-process nuclides,a monoenergetic 3.4 MeV proton beam produced by the tandem-accelerator in the China Institute of Atomic Energy was utilized.The proton beam was first transmitted through a 60.5μm aluminum foil and then impinged on a natural LiF target to produce neutron beam via^(7)Li(p,n)7Be reaction.The quasi-Gaussian energy distribution of protons in the LiF target resulted in neutron energy spectra that agreed with a Maxwellian energy distribution at kT=(22±2)keV,which was achieved by integrating neutrons detected within an emission angle of 65.0°±2.6°using a ^(6)Li glass detector positioned at 65°relative to the proton beam direction.The narrow angular spread of the Maxwelliandistributed neutron beam enables direct measurement of neutron capture cross-sections for most s-process nuclides,overcoming previous experimental limitations associated with broad angular distributions.
