Direct heating of a laser-imploded core by ultraintense laser-driven ions

Area of Science:

• Nuclear Fusion Energy
• Plasma Physics
• Laser-Plasma Interactions

Background:

• Achieving controlled nuclear fusion requires efficient core heating and ignition.
• Current methods face challenges in energy deposition and achieving desired neutron yields.

Purpose of the Study:

• Introduce and evaluate a novel direct core heating fusion process.
• Investigate the role of energetic ions and hot electrons in plasma heating and ignition.
• Assess the potential for high-gain fusion.

Main Methods:

• Utilized an extremely energetic ultrashort pulse laser (LFEX) to drive energetic ions.
• Observed D(d,n)^{3}He-reacted neutrons (DD beam-fusion neutrons) and thermal neutrons.
• Employed 1D hydrocode (STAR 1D) for implosion dynamics and 2D collisional particle-in-cell code for core heating predictions.

Main Results:

• Observed DD beam-fusion neutrons (5×10^{8} n/4π sr) and thermal neutrons (6×10^{7} n/4π sr).
• Verified direct ion collision with core plasma and local energy deposition forming hot spots.
• Identified limitations in current core density (2 g/cm³) affecting energy deposition and neutron yield.

Conclusions:

• The proposed direct core heating scheme shows potential for high-gain fusion.
• Energetic ions and hot electrons are crucial for core heating and ignition.
• Increasing core density is essential for enhancing energy deposition and neutron yield in future experiments.