Partial photoneutron cross sections for the isomeric state 180Tam

Area of Science:

• Nuclear Physics
• Astrophysics
• Nuclear Astrophysics

Background:

• Tantalum-180m is an astrophysically significant isomer.
• Understanding its production mechanism is crucial for nucleosynthesis models.

Purpose of the Study:

• Determine photoneutron cross sections for (181)Ta(γ, n)(180)Ta(m).
• Investigate the nuclear level density of (180)Ta.
• Clarify the role of (180)Ta(m) in stellar nucleosynthesis.

Main Methods:

• Simultaneous measurement of total and ground-state cross sections using laser Compton-backscattered rays.
• Employed direct neutron counting for total cross sections (σ_tot).
• Utilized photoactivation for ground-state cross sections (σ_gs).

Main Results:

• Partial cross sections for the isomeric state of (180)Ta were determined.
• These cross sections serve as a novel probe of nuclear level density in (180)Ta.
• The results offer implications for p- and s-process nucleosynthesis.

Conclusions:

• The study provides crucial data on tantalum photodisintegration.
• Findings contribute to understanding the formation of the astrophysically important (180)Ta(m) isomer.
• This research refines models of stellar nucleosynthesis.