Properties of ^{187}Ta Revealed through Isomeric Decay

Area of Science:

• Nuclear Physics
• Atomic Physics

Background:

• Investigating nuclear structure and properties of exotic isotopes is crucial for understanding nuclear forces.
• The mass region around Z=114 and N=187 is predicted to exhibit interesting nuclear shape phenomena.

Purpose of the Study:

• To synthesize and characterize a high-spin isomeric state of ^{187}Ta for the first time.
• To investigate the nuclear shape evolution and decay properties in this mass region.

Main Methods:

• Utilizing multinucleon transfer reactions to produce ^{187}Ta.
• Employing an argon gas-stopping cell and laser ionization for mass separation and identification.
• Analyzing internal gamma-ray emissions to determine isomer properties.

Main Results:

• Successfully produced and identified a ^{187}Ta isomer in a high-spin state.
• Characterized the isomer with a half-life (T_{1/2}) of 7.3±0.9 seconds at 1778±1 keV.
• Observed decay through a rotational band with perturbations indicating a prolate-oblate shape transition.
• Calculated a reduced E2 hindrance factor (f_{ν}) of 27±1, supporting approximate axial symmetry.

Conclusions:

• The first production of a ^{187}Ta isomer opens new avenues for nuclear spectroscopy in this region.
• The observed shape transition and conserved axial symmetry provide critical data for nuclear structure models.