The neutron imaging diagnostic at NIF (invited)

Area of Science:

• Nuclear Fusion Science
• Plasma Physics
• High-Energy-Density Physics

Background:

• The National Ignition Facility (NIF) requires advanced diagnostics for inertial confinement fusion (ICF) research.
• Understanding the dynamics of burning plasma is crucial for achieving ignition.

Purpose of the Study:

• To introduce and detail a new neutron imaging diagnostic system at NIF.
• To characterize the size, shape, and fuel distribution of burning plasma during ICF implosions.

Main Methods:

• Utilizes a pinhole neutron aperture and a 28m flight path for neutron detection.
• Employs chromatic separation to capture two distinct images of neutron energy distributions (14 MeV and 6-12 MeV).
• Measures the two-dimensional distribution of neutrons to reconstruct plasma characteristics.

Main Results:

• Successfully commissioned a neutron imaging diagnostic at NIF.
• Acquired data on the size and shape of the burning DT plasma core.
• Provided measurements of the quantity and spatial distribution of cold fuel surrounding the plasma.

Conclusions:

• The new neutron imaging diagnostic is a valuable tool for ICF studies at NIF.
• The diagnostic provides critical data for understanding plasma behavior and fuel assembly in ICF implosions.
• This system enhances the capability to study the ignition stage of ICF.