Low Fuel Convergence Path to Direct-Drive Fusion Ignition

Area of Science:

• Nuclear Fusion Energy
• Plasma Physics
• Inertial Confinement Fusion

Background:

• Inertial confinement fusion (ICF) research aims to achieve controlled thermonuclear fusion for energy production.
• Achieving robust ignition in ICF requires overcoming challenges like hydrodynamic instabilities and laser-plasma interactions.
• Traditional ICF approaches often face limitations in efficiency and stability at relevant energy scales.

Purpose of the Study:

• To present a new class of inertial fusion capsules for robust ignition.
• To explore the use of multishell targets with low-intensity laser direct drive.
• To mitigate Rayleigh-Taylor instabilities and enhance hydrodynamic efficiency.

Main Methods:

• Development of a novel capsule design featuring three concentric, heavy metal shells.
• Utilizing laser direct drive at a low intensity of 2.8×10^14 W/cm².
• Enclosing liquid deuterium-tritium fuel within the target volume.

Main Results:

• Ignition is designed to occur 'upstream' from stagnation, minimizing pusher deceleration.
• The low laser intensity avoids thresholds for laser plasma instability and cross-beam energy transfer.
• Achieved high hydrodynamic efficiency of approximately 10%.

Conclusions:

• The proposed multishell capsule design offers a robust pathway to ignition in ICF.
• Low-intensity direct drive with advanced target design can overcome key instability challenges.
• This approach demonstrates potential for efficient and stable inertial fusion energy development.