Gamma Radiation from the Inelastic Scattering of Protons by F19
Gamma Radiation from the Inelastic Scattering of Protons by F19
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F19 质子非弹性散射产生的伽马辐射
DOI：
10.1103/physrev.97.1226
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发表时间：
1955
期刊：
影响因子：
--
通讯作者：
C. Barnes
中科院分区：
文献类型：
--
作者：
C. Barnes
通过探测闪烁计数器中产生的伽马辐射，研究了质子的非弹性散射激发F19的109 keV和197 keV激发态的绝对截面随1750keV能量的变化。各种F19(p，α)O16反应的大部分共振表现为激发这些低能级中的一个或两个的共振。对这两种伽马射线的角分布进行了详细的研究，再加上Thirion，Barnes和Lauritsen对这两种态寿命的直接测量，以及Sherr，Li和Christy的库仑激发功，得出了如下的指认：109-keV态，J=1/2，奇宇称；197-keV态，J=5/2，偶宇称。在低入射质子能量下，197keV伽马射线的非共振产额与库仑激发的预期产额大致相同。109keV伽马射线的非共振产额超过了预期的库仑激发。结合本实验室最近由Peterson、Webb、Hagedorn和Fowler对F19(p，α)O16反应的弹性散射的测量，以及对F19(p，N20)O16反应的早期测量，共振非弹性截面允许重新确定N20化合物核态的各种衰变模式的部分宽度。
The absolute cross section for the excitation of the 109-kev and 197-kev excited states of F19, by the inelastic scattering of protons, has been studied as a function of bombarding energy up to 1750 kev by detecting the resultant gamma radiation in scintillation counters. Most of the resonances for the various F19(p, α)O16 reactions appear as resonances for the excitation of one or both of these low-lying states. A detailed study of the angular distributions of the two gamma rays, together with the direct measurements of the lifetimes of these states by Thirion, Barnes, and Lauritsen, and the Coulomb excitation work of Sherr, Li, and Christy, leads to the assignments: 109-kev state, J=1 / 2, odd parity; 197-kev state, J=5 / 2, even parity. The nonresonant yield of 197-kev gamma rays is approximately that expected from Coulomb excitation at low incident proton energies. The nonresonant yield of 109-kev gamma rays exceeds the expected Coulomb excitation. In conjunction with the recent measurements of the elastic scattering of protons by F19 made by Peterson, Webb, Hagedorn, and Fowler, in this laboratory, and older measurements of the F19(p, α)O16 reactions, the resonant inelastic cross sections allow a new determination of the partial widths for the various modes of decay of the Ne20 compound nuclear states.