High-density carbon capsule experiments on the national ignition facility

Area of Science:

• Nuclear Fusion Science
• Materials Science for Fusion Energy
• Plasma Physics

Background:

• Inertial confinement fusion (ICF) requires robust ablator materials for capsule implosions.
• High-density carbon (HDC) is a candidate material with potentially advantageous properties.

Purpose of the Study:

• To evaluate the performance of high-density carbon (HDC) as an ablator material in indirect-drive ICF implosions.
• To assess the laser-target coupling and nuclear performance of HDC capsules on the National Ignition Facility (NIF).

Main Methods:

• Conducted a series of five indirect-drive implosion experiments using 76-μm-thick HDC capsules.
• Utilized a four-shock laser pulse optimized for HDC, delivering 1.3 MJ of energy and 360 TW peak power.
• Filled capsules with deuterium and tritium for nuclear yield measurements.

Main Results:

• Demonstrated efficient laser to target coupling, achieving approximately 90% efficiency.
• Achieved a maximum neutron yield of 1.6×10^15 ± 3×10^13.
• Observed a yield over one-dimensional simulations of 70%, indicating excellent nuclear performance.

Conclusions:

• High-density carbon (HDC) shows promise as an effective ablator material for inertial confinement fusion.
• The experimental results validate HDC's suitability for achieving high performance in NIF implosions.
• Further research into HDC properties can advance ICF target designs.