| Autor: |
Stephen Sanders, R. G. Henry, M. P. Carpenter, T. L. Khoo, C. J. Lister, T. Lauritsen, B. Crowell, D. Nisius, E. F. Moore, R. V. F. Janssens, D. Gassman, D. J. Blumenthal, H. Amro, M.W. Drigert, I. Ahmad, W. F. Henning |
| Rok vydání: |
1995 |
| Předmět: |
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| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 99:308-311 |
| ISSN: |
0168-583X |
| DOI: |
10.1016/0168-583x(94)00687-3 |
| Popis: |
We performed an experiment to search for the two-phonon octupole vibrational state in {sup 208}Pb. Thick targets of {sup 208}Pb, {sup 209}Bi, {sup 58,64}Ni, and {sup 160}Gd were bombarded with 1305 MeV beams of were bombard {sup 208}Pb supplied by ATLAS. Gamma rays were detected using the Argonne-Notre Dame BGO gamma-ray facility, consisting of 12 Compton-suppressed germanium detectors surrounding an array of 50 BGO scintillators. We identified some 30 known gamma rays from {sup 208}Pb in the spectra gated by the 5{sup -} {yields} 3{sup -} and 3{sup -} {yields} 0{sup +} transitions in {sup 208}Pb. In addition, after unfolding these spectra for Compton response, we observed broad coincident structures in the energy region expected for the 2-phonon states. Furthermore, we confirmed the placement of a 2485 keV line observed previously in {sup 207}Pb and find no evidence consistent with the placement of this line in {sup 208}Pb. We are currently in the process of investigating the origin of the broadened lines observed in the spectra, extracting the excitation probability of states in {sup 208}Pb, and determining the relative probability of mutual excitation and neutron transfer in this reaction. An additional experiment is also being performed to collect much highermore » statistics germanium-germanium coincidence data for the thick {sup 208}Pb target.« less |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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