Study of excited states in [sup 85]Kr and [sup 86]Kr: Evidence for neutron-core excitations in the [ital N]=50 nucleus [sup 86]Kr

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.48.1010· OSTI ID:6216111

Winter, G; Schwengner, R; Reif, J; Prade, H ^[1]; Funke, L ^[2]; Wirowski, R; Nicolay, N; Dewald, A; von Brentano, P ^[3]; Grawe, H; Schubart, R ^[4]

---

1. Institut fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, D-01314 Dresden (Germany)
2. Ingenieurgesellschaft IAF Dresden, D-01326 Dresden (Germany)
3. Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Koeln (Germany)
4. Hahn-Meitner-Institut Berlin, D-14109 Berlin (Germany)

High-spin states of the [ital N]=49,50 nuclei [sup 85,86]Kr have been investigated via the reactions [sup 82]Se([sup 7]Li,[ital p]3[ital n]) or [sup 82]Se([sup 7]Li,[ital p]2[ital n]), respectively, using 32 MeV [sup 7]Li ions. In order to suppress [gamma] rays arising from pure neutron evaporation the measurements of angular distributions and relative excitation functions of the [gamma] rays as well as [gamma][gamma] coincidences have been performed in particle-[gamma] coincidence modes. Additional information on excited states in [sup 85]Kr has been obtained in connection with the [sup 82]Se([alpha],[ital n]) reaction at beam energies between 13 and 21 MeV. The level scheme of [sup 85]Kr has been extended by a new sequence of high-spin states with excitation energies up to 4.8 MeV and tentative spins up to (23/2) that is built on top of the 17/2[sup +] [mu]s isomer at 1991.8 keV. For [sup 86]Kr a new level scheme of high-spin states with excitation energies up to 7.9 MeV and tentative spins up to (12) has been observed for the first time. The level sequences observed in [sup 85,86]Kr are interpreted on the basis of shell-model calculations in the configuration space 1[ital p][sub 3/2], 0[ital f][sub 5/2], 1[ital p][sub 1/2], and 0[ital g][sub 9/2] for the protons and 0[ital g][sub 9/2] or 0[ital g][sub 9/2], 1[ital d][sub 5/2] for the neutrons in [sup 85]Kr or [sup 86]Kr, respectively. The inclusion of neutron-core excitations in the calculations for [sup 86]Kr results in a remarkably improved agreement between experimental and calculated level energies. In this way considerable contributions of neutron-core excitations are strongly suggested for the positive-parity yrast states with spins 7[h bar], 9[h bar], and 10[h bar].

• OSTI ID: 6216111
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 48:3; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

663110* -- General & Average Properties of Nuclei & Nuclear Energy Levels-- (1992-)
663220 -- Electromagnetic Transitions-- (1992-)
663550 -- Nuclear Mass Ranges-- A=59-89-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHARGED-PARTICLE REACTIONS
COINCIDENCE METHODS
COINCIDENCE SPECTROMETRY
COUNTING TECHNIQUES
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXCITED STATES
FERMIONS
GAMMA SPECTROSCOPY
HADRONS
HEAVY ION REACTIONS
HIGH SPIN STATES
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON 85
KRYPTON 86
KRYPTON ISOTOPES
LITHIUM 7 REACTIONS
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 10-100
MICROSEC LIVING RADIOISOTOPES
NANOSEC LIVING RADIOISOTOPES
NEUTRONS
NUCLEAR CORES
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
PARTICLE PROPERTIES
PROTONS
RADIOISOTOPES
SELENIUM 82 TARGET
SHELL MODELS
SPECTROSCOPY
SPIN
STABLE ISOTOPES
TARGETS
YEARS LIVING RADIOISOTOPES