title: In Situ Real-Time Radiographic Study of Thin Film Formation Inside Rotating Hollow Spheres.
abstract: Hollow spheres with uniform coatings on the inner surface have applications in optical devices, time- or site-controlled drug release, heat storage devices, and target fabrication for inertial confinement fusion experiments. The fabrication of uniform coatings, which is often critical for the application performance, requires precise understanding and control over the coating process and its parameters. Here, we report on in situ real-time radiography experiments that provide critical spatiotemporal information about the distribution of fluids inside hollow spheres during uniaxial rotation. Image analysis and computer fluid dynamics simulations were used to explore the effect of liquid viscosity and rotational velocity on the film uniformity. The data were then used to demonstrate the fabrication of uniform sol-gel chemistry derived porous polymer films inside 2 mm inner diameter diamond shells.
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Tom
authors.initials: T
authors.lastname: Braun
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Walton
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Christoph
authors.initials: C
authors.lastname: Dawedeit
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Monika M
authors.initials: MM
authors.lastname: Biener
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Trevor M
authors.initials: TM
authors.lastname: Willey
authors.affiliation: Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States.
authors.forename: Xianghui
authors.initials: X
authors.lastname: Xiao
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Anthony
authors.initials: A
authors.lastname: van Buuren
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Alex V
authors.initials: AV
authors.lastname: Hamza
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, United States.
authors.forename: Juergen
authors.initials: J
authors.lastname: Biener
keywords: aerogel; coating; flows; hollow sphere; inertial confinement fusion (ICF); liquid films; sol−gel films; uniformity