A New Cosmic Dust Detector with a Novel Method Using a Resistive Grid Sensitive to Hypervelocity Impacts

A new method is demonstrated to detect impacts of hypervelocity particles in real-time and to determine the size of particles. It uses a resistive grid on a thin substrate (here Duroid). Penetration of the substrate in an impact breaks lines on the grid, changing the overall resistance of the grid. The change in resistance is proportional to the width of the damaged area (i.e. number of resistive lines that are broken), which is in turn proportional to the impactor size. This method provides a large area, low mass, low power detector for measuring the flux of small dust particles in space. Based on experimental data (taken in a two-stage light gas gun), we show that impacts at 5 km s-1 demonstrate that the principle works as described for particles 150 μm and above and that in theory could work for impacts down to size scales as small as 50 μm.