Enhanced Isomer Population via Direct Irradiation of Solid-Density Targets Using a Compact Laser-Plasma Accelerator.

Area of Science:

• Nuclear Physics
• Plasma Physics
• Laser-driven Acceleration

Background:

• Understanding nuclear level densities and gamma strength functions is crucial for nuclear structure and astrophysics.
• Laser-plasma accelerators offer novel ways to probe nuclear matter with intense, ultrashort electron beams.

Purpose of the Study:

• To investigate the excitation of long-lived nuclear states in bromine using a tabletop laser-plasma accelerator.
• To probe nuclear quasicontinuum properties and explore electron-nuclear interactions.
• To assess the potential impact on nuclear waste management and astrophysics.

Main Methods:

• Utilized a tabletop laser-plasma accelerator to generate pulsed electron beams (<100 fs).
• Employed solid-density active Lanthanum(III) bromide (LaBr3) targets.
• Measured the isomeric ratio of Bromine-80 (80^mBr/80^gBr) following electron irradiation.

Main Results:

• Observed a significant enhancement of the 80^mBr/80^gBr isomeric ratio by a factor of 4.354±0.932 compared to bremsstrahlung.
• Demonstrated the capability of laser-produced electron beams to excite long-lived nuclear states.
• Indicated possible angular momentum coupling via electron-nuclear interactions.

Conclusions:

• Laser-plasma acceleration provides a sensitive method for studying nuclear quasicontinuum properties.
• The observed enhancement suggests novel mechanisms for nuclear excitation and angular momentum transfer.
• Further research could impact long-term nuclear waste storage and understanding of heavy element nucleosynthesis.