Hohlraum-driven ignitionlike double-shell implosions on the omega laser facility.

Area of Science:

• * Nuclear Fusion and Plasma Physics
• * Inertial Confinement Fusion (ICF) research

Background:

• * Achieving ignition in inertial confinement fusion (ICF) requires precise control over implosion dynamics.
• * Double-shell targets are a promising approach for ICF, but are susceptible to fuel-pusher mix.
• * Previous experiments have explored various hohlraum designs and diagnostic techniques.

Purpose of the Study:

• * To investigate high-convergence ignitionlike double-shell implosions on the Omega laser facility.
• * To experimentally infer neutron production during the compressional phase of double-shell implosions.
• * To assess the impact of design optimization and fabrication on implosion performance and mix mitigation.

Main Methods:

• * Utilized cylindrical gold hohlraums with 40 drive beams on the Omega laser.
• * Employed time-resolved core x-ray imaging to diagnose the implosion dynamics.
• * Focused on fall-line design optimization and stringent fabrication standards for targets.

Main Results:

• * Achieved repeatable, dominant primary (2.45 MeV) neutron production.
• * Inferred neutron production from the mix-susceptible compressional phase.
• * Demonstrated experimental evidence supporting the importance of precise implosion control.

Conclusions:

• * Effective control of fuel-pusher mix during final compression is essential for ignition.
• * These findings are critical for the development of double-shell targets for the National Ignition Facility (NIF).
• * Highlights the necessity of advanced target fabrication and diagnostic capabilities for fusion energy research.