Final Report for DE-FG52-03NA00076 [electronic resource]
Nuclear Level Densities; Radiative Stength Function.
Saved in:
| Online Access: |
Online Access |
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| Corporate Author: | |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. National Nuclear Security Administration ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2006.
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| Subjects: |
| Summary: | Nuclear Level Densities; Radiative Stength Function. |
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| Abstract: | Level densities and radiative strength functions are crucial for stewardship science, in particular for radiochemical studies. In addition, this information is key to undertanding nucleosynthesis and thus very important for astrophysics. We utilized a method derives simultaneously the nuclear level density and the radiative strength function for energy regions that are extremely difficult to study via other methods. In heavy nuclei there is evidence for the systematic appearance of a low energy resonance in the radiative strength function (the so-called pygmy resonance). We have studied the same final nuclide (171Yb) via different nuclear reactions and obtained the same energy and width for the pygmy resonance. We also extended the method to lighter nuclei, including 56,57Fe, 93-98Mo and 116,117Sn. For the iron and molybdenum isotopes an enhancement of the radiative strength function was observed at low energy. Subsequent measurements in iron appear to confirm this unusual effect. Our measurements in tin do not observe this enhancement, nor did any of the earlier measurements in heavy nuclei. The issue is still unsettled. |
| Item Description: | Published through SciTech Connect. 10/16/2006. G. E. Mitchell. |
| Type of Report and Period Covered Note: | Final; |