Pulsed-Plasma Sputter Deposition of Diamond-Like Carbon Ablators

Alison Engwall | 22-FS-027

Project Overview

Diamond-like carbon (DLC) is a material of interest as a next-generation inertial confinement fusion (ICF) ablator, an application which requires coatings of thickness greater than 50 micrometers. Pulsed-plasma sputter deposition is a relatively new method for depositing DLC coatings that has shown promise in growing DLC films with advantageous properties, but film thickness has been limited to a few micrometers due to high stress.

In this project, we systematically varied pulsed-plasma deposition conditions and identified a process window in which uniform, amorphous DLC films were deposited with less than 300 MPa residual compressive stress. The microstructure of these films was found to be insensitive to substrate tilt angle, a promising result for deposition on nonplanar surfaces. Importantly, we were able to successfully demonstrate deposition of films over 50 micrometers thick. The results of this study support pulsed-plasma sputter deposition as a viable synthesis method for further DLC ablator development.

Mission Impact

This project advances the Laboratory's core competency in advanced materials and manufacturing by expanding our understanding of and ability to produce a new material. The development of a new ablative coating also opens new opportunities in target design for high-energy-density science and ICF experiments.