General Atomics (GA) and LLNL characterization techniques/equipment include the following:
- Atomic force microscopy: A molecular imaging atomic force microscope system is used to measure target material surfaces with nanometer spatial and height resolution.
- Confocal microscope 4-pi capsule inspection system: This system allows particles as small as a few microns introduced during assembly to be identified and their location translated to NIF Target Chamber coordinates for that specific target (see Figure 5-4a).
- Contact radiography (CR): A nondestructive technique to precisely profile graded dopants in Inertial Confinement Fusion (ICF) shells, this quantitative CR method can detect dopant variation to an atomic percentage of better than 0.1 percent. CR also provides accurate dimensional information.
- Double-sided white-light interferometer: A double-sided white-light interferometer scans both sides of a sample simultaneously to provide thickness measurements over the sample area. 3D mapping of ripple and steps in target components to ~1 micron accuracy has been achieved.
- Dual-confocal measurement system: A dual-confocal measurement system performs thickness measurements over a sample area for opaque samples to complement its x-ray edge absorption spectroscopy unit. 3D mapping of ripples and steps in target components to ~1 micron accuracy has been achieved.
- Energy dispersive spectroscopy (EDS): A physics-based EDS model examines capsule contaminants and dopants by measuring low concentrations of relatively light elements in a very low-Z matrix.
- Focused ion beam with scanning electron microscopy: Focused-ion-beam characterization enables site-specific analysis of various capsules by conveniently cutting open the thick coating layers and revealing the internal microstructures, defects (if any exist), and composition details.
- Ion beam characterization: A 4 MV ion accelerator is used to characterize ion implantation doping of ICF ablator capsules with 124Xe atoms and potentially other elements of interest to neutron capture experiments.
- Micro x-ray computed tomography: An x-ray computed tomography system images materials with a resolution of less than 1 micrometer over a 1-millimeter field of view to provide spatially resolved opacity that can be translated to density in known compositions and thicknesses.
- Nikon NEXIV optical coordinate measuring machine: This instrument is equipped with custom analysis software for automated mandrel dimensional metrology.
- Phase shifting diffractive interferometry: The interferometer uses 110 images (medallions) to capture all isolated and gently curved defects on the entire shell surface.
- Precision radiography: A precision radiography system measures x-ray opacity variation in an ablator capsule to 10–4 accuracy at 120-micron spatial resolution; this includes variations caused by nonuniformity of the dopant layers.
- Scanning electron microscopy: A scanning electron microscopy with EDS is used for determining capsule dopant profiles and hohlraum microstructure.
- Transmission electron microscopy with electron energy loss: The transmission electron microscope with electron energy loss spectroscopy capability offers analysis at the atomic structure level and extremely high energy resolution for composition analysis of capsule materials.
- X-ray edge absorption spectroscopy: An x-ray absorption spectroscopy instrument measures the absorption edge to determine the concentration of elements (Z>17) in the presence of other elements. It can also be used to determine the thickness of opaque samples.
- X-ray fluorescence (XRF): The XRF system calculates the atomic percentage of elements in spherical samples with an accuracy of 10% for high-Z elements and has a trace detection capability at 1 ppm level for contamination control.
- X-ray microscopy: A commercial (Xradia) point projection x-ray microscope is used to measure/characterize laser-drilled fill hole geometries to ~1.5-micron resolution.
