Proton states in the Z = 99 nucleus /sup 251/Es excited by /sup 251/Fm electron capture decay and /sup 250/Cf(. cap alpha. ,t) reaction

Journal Article · Thu Jun 01 04:00:00 EDT 1978 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.17.2163· OSTI ID:7083661

Ahmad, I; Sjoblom, R K; Friedman, A M; Yates, S W

Level structure of the Z = 99 nucleus, /sup 251/Es, has been investigated by measuring the ..gamma.. rays and conversion electrons associated with the electron capture decay of 5.3-h /sup 251/Fm, and from triton spectra produced in the /sup 250/Cf(..cap alpha..,t)/sup 251/Es reaction. The ..gamma..-ray spectra were measured with a 2-cm/sup 2/ x 5-mm planar and a 25-cm/sup 3/ coaxial Ge(Li) detector and the electron spectra were measured with a cooled Si(Li) detector. Forty-five ..gamma.. rays were identified in /sup 251/Es and the multipolarities of most of the transitions were deduced. Logft values for the observed electron capture transitions were derived from the measured electron capture transition intensities. A two-parameter ..gamma..-..gamma.. coincidence experiment was performed to determine the relationships between various ..gamma.. transitions. Triton spectra from the /sup 250/Cf(..cap alpha..,t)/sup 251/Es reaction were analyzed with an Enge split-pole magnetic spectrograph. On the basis of the present investigation the following intrinsic states were identified in /sup 251/Es: 3/2 - (521), 0; 7/2 + (633), 8.3; 1/2 - (521), 411; 7/2 - (514), 461.4; 9/2 + (624), 777.9; )7/2 + (633) x 2 + )/sub 11/2+/ vibrational state, 889.1; )n(734)9/2 - ; n(620)1/2 + ; p(521)3/2 - )/sub 11/2+/ three-quasiparticle state, 1239.0 keV. A K..pi.. = 11/2 + state at 1264.9 keV was interpreted as a three-quasiparticle state but could not be given a definite assignment. This is the first time a definite identification of the proton orbitals 1/2 -(521) and 7/2 - (514) has been made in any nucleus.

• Research Organization: Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439
• OSTI ID: 7083661
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 17:6; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

652022* -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Radioactive Decay-- (-1987)
652023 -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Energy Levels & Transitions-- (-1987)
652025 -- Nuclear Properties & Reactions
A=220 & above
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
ALPHA REACTIONS
BARYONS
BASIC INTERACTIONS
BETA DECAY
BETA DECAY RADIOISOTOPES
BRANCHING RATIO
CALIFORNIUM 250 TARGET
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
DAYS LIVING RADIOISOTOPES
DECAY
DIRECT REACTIONS
EINSTEINIUM 251
EINSTEINIUM ISOTOPES
ELECTRON CAPTURE DECAY
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
EVEN-ODD NUCLEI
FERMIONS
FERMIUM 251
FERMIUM ISOTOPES
FT VALUE
GAMMA SPECTRA
HADRONS
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INTERACTIONS
ISOTOPES
LEPTONIC DECAY
MEV RANGE
MEV RANGE 10-100
MULTIPOLARITY
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
PARTICLE DECAY
PROTONS
RADIOISOTOPES
SINGLE-PARTICLE MODEL
SPECTRA
STRIPPING
TARGETS
TRANSFER REACTIONS
TRITONS
WEAK INTERACTIONS
WEAK PARTICLE DECAY