0000000000542211
AUTHOR
Laurent Jeannot
Spatial Reconstruction Algorithm of DT Layer in Cryogenic Targets Using Optical Techniques
The measurements of the solid DT layer, in terms of thickness and roughness, in the LMJ geometry (i.e. in a hohlraum) are not trivial. The DT layer measurements will be done using a Matsukov-Cassegrain telescope placed 39 cm away from the target. This telescope will be used to acquire shadowgraphy images on equators, and interferometric measurements on pole areas using optical coherence tomography (OCT). Optical coherence tomography allows determining the DT layer thickness on a few points, in the polar regions of the target. By scanning around the poles, several points can be acquired in order to calculate the roughness and the local shape of the DT layer at the pole. Both techniques were …
A Model to Characterize the D-T Layer of ICF Targets by Backlit Optical Shadowgraphy
A numerical model is presented in order to modelize the bright ring that appears in backlit optical shadowgraphy on a transparent hollow sphere with a solid deuterium-tritium layer inside. This novel model is based on computational calculations applied to the problem of the targets used in inertial confinement fusion. The model takes into account the influences of the optical imaging system (numerical aperture, source divergence, camera resolution, etc.) and the effect of the capsule itself, diameter, thickness, and refractive index, and allows one to analyze the inner surface of a capsule in terms of thickness and roughness.