Pygmy dipole strength close to particle-separation energies - the case of the Mo isotopes
Gencho Rusev, Eckart Grosse, Martin Erhard, Arnd Junghans, Krasimir Kosev, Klaus-Dieter Schilling, Ronald Schwengner, Andreas Wagner
Abstract
The distribution of electromagnetic dipole strength in 92, 98, 100 Mo has been investigated by photon scattering using bremsstrahlung from the new ELBE facility. The experimental data for well separated nuclear resonances indicate a transition from a regular to a chaotic behaviour above 4 MeV of excitation energy. As the strength distributions follow a Porter-Thomas distribution much of the dipole strength is found in weak and in unresolved resonances appearing as fluctuating cross section. An analysis of this quasi-continuum - here applied to nuclear resonance fluorescence in a novel way - delivers dipole strength functions, which are combining smoothly to those obtained from (g,n)-data. Enhancements at 6.5 MeV and at ~9 MeV are linked to the pygmy dipole resonances postulated to occur in heavy nuclei.
Create a lesson
Related papers
Direct measurement of the in-medium η mass spectrum through the γγ decay channel
Y. Matsumura, N. Muramatsu, T. A. Hashimoto et al.
STAR Highlights II: Study of Small Systems and the Search for New, Exotic Physics
Jiangyong Jia
Cluster emission and its impact on the r-process nucleosynthesis
Natalia Thomas, Silvia Bara, Thomas Elias Cocolios et al.
Core Breaking at Low Spin in 68Zn from Nuclear Resonance Fluorescence
S. R. Johnson, R. V. F. Janssens, B. A. Brown et al.
Isoscalar Giant Resonances in the even-A Pd Isotopes
J. Arroyo, U. Garg, T. Furuno et al.
Efficient production of 229m,gTh via neutron capture in VUV-transparent crystals
Zhong-yi Chen, Hao-yang Lan, Di Wu et al.