2025/10/14 by Martin Ryzy, Guqi Yan, Ryzy, Martin +11
Engineering · Materials Science · Physics and Astronomy · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Laser-Plasma Interactions and Diagnostics #Materials Science (cond-mat.mtrl-sci) #Optics (physics.optics) #Plasma Physics (physics.plasm-ph) #Ultrasonics and Acoustic Wave Propagation #Ultrasound and Cavitation Phenomena
paper · pdf · doi:10.48550/arxiv.2510.15997
openalex publication_date 2025/10/14 · openalex created_date 2025/10/22 · openalex updated_date 2026/07/31
In inertial confinement fusion experiments hollow, spherical mm-sized capsules are used as a container for nuclear fuel. To achieve maximum implosion efficiency, a perfect capsule geometry is required. This paper presents a wall thickness measurement method based on zero-group velocity guided elastic wave resonances. They are measured with a non-destructive, contactless frequency domain laser ultrasound microscopy system. Wall thickness measurements along the equator of a high-density carbon capsule with a diameter of around 2 mm and a wall thickness of around 80 \unicodex00B5m excellently agree with infrared interferometry reference measurements. In addition, the multi-resonant nature of a spherical shell is studied by complementing experimental observations with plate dispersion calculations and finite element wave propagation simulations. The presented method is scalable and can be applied to a broad range of target materials, including metals, or metal-doped targets.