Electromagnetic decays of excited states in {sup 261}Sg (Z=106) and {sup 257}Rf (Z=104)

Journal Article · Tue Jun 15 04:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.81.064325· OSTI ID:21388600

Berryman, J S; Clark, R M; Gregorich, K E; Cromaz, M; Dvorak, J; Fallon, P; Gros, S; Lee, I Y; Macchiavelli, A O; Paschalis, S; Petri, M; Qian, J ^[1]; Allmond, J M ^[2]; Bleuel, D L; Stoyer, M A; Wiedeking, M ^[3]; Dragojevic, I; Ellison, P A; Garcia, M A ^[1]

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1. Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2. Department of Physics, University of Richmond, Virginia 23173 (United States)
3. Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

An isomeric one-quasineutron state, likely based on the [725]11/2{sup -} Nilsson level, was identified in {sup 261}Sg by its decay via internal conversion electrons. The state has an excitation energy of approx =200 keV and a half-life of 9.0{sub -1.5}{sup +2.0} mus. {sup 261}Sg has the highest Z and A of any nucleus in which the electromagnetic decay of an isomeric state was observed to date. A separate experiment was performed on the alpha daughter nucleus of {sup 261}Sg, namely {sup 257}Rf. Spectroscopy of delayed gamma rays and converted electrons from {sup 257}Rf resulted in the identification of a K isomer at an excitation energy of approx =1125 keV with a half-life of 134.9 +- 7.7 mus. The spin of the isomeric state is tentatively assigned I=21/2,23/2 and the state likely decays to a rotational band built on the [725]11/2{sup -} Nilsson level via a DELTAK=5 or 6 transition. The present results provide new information on excited states in the transactinide region, which is important for testing models of the heaviest elements.

• OSTI ID: 21388600
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 6 Vol. 81; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY RADIOISOTOPES
ANGULAR MOMENTUM
CONVERSION
DECAY
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVEN-ODD NUCLEI
EXCITATION
EXCITED STATES
FERMIONS
GAMMA RADIATION
HALF-LIFE
HEAVY NUCLEI
INTERNAL CONVERSION
IONIZING RADIATIONS
ISOMERS
ISOTOPES
KEV RANGE
KEV RANGE 100-1000
LEPTONS
MILLISECONDS LIVING RADIOISOTOPES
NUCLEAR DECAY
NUCLEI
PARTICLE PROPERTIES
RADIATIONS
RADIOISOTOPES
ROTATIONAL STATES
RUTHERFORDIUM 257
RUTHERFORDIUM ISOTOPES
SEABORGIUM 261
SEABORGIUM ISOTOPES
SECONDS LIVING RADIOISOTOPES
SPECTROSCOPY
SPIN
SPONTANEOUS FISSION RADIOISOTOPES