Size-Dependent Phenomena in Angle-Resolved Measurements of Submicron Sn Particle Scattering from a Molybdenum Surface

Abstract

Nanoparticle scattering dynamics play a critical role in a wide range of astrophysical, industrial, and ambient environments; however, experimental data to guide theoretical models that predict this behavior are lacking. The experiments reported here examine these phenomena using single massselected, charged, submicron solid tin particles covered with an oxide layer of ∼10 nm thickness that are accelerated with varying energies onto a highly polished molybdenum surface. The scattering angle and speed for each backscattering event were measured and analyzed, revealing notable size-dependent trends in the coefficient of restitution and onset of sticking and charge transfer over the range from 150 to 500 nm diameter. The experimental results are interpreted using a mechanical model of the measured impact behavior, extending particle scattering measurements into a new intermediate size range, important for understanding the transport of submicron tin particles. An empirical scaling rule is also presented that normalizes the size-dependent behavior in terms of the ratio of the incident kinetic energy and impact contact area.

Production and Impact Characterization of Enceladus Ice Grain Analogues

“…This is expected because the CoR increases with decreasing particle size as a result of a size dependence in the yield strength property of the particle, as described in a study of submicron-diameter tin particle impacts. 23 The overall CoR trend of these micron ice particles is similar to that reported for submicron tin and also polystyrene latex spheres. 22,23 There are additional considerations in the classification of fragmentation events.…”

“…23 The overall CoR trend of these micron ice particles is similar to that reported for submicron tin and also polystyrene latex spheres. 22,23 There are additional considerations in the classification of fragmentation events. The events displayed in Figure 5 may not be capturing every fragmentation event that is occurring after the impact.…”

“…There have been several CoR studies of ice particles impacting hard surfaces but all for much larger particles (millimeter-to-centimeter-sized) and much slower incident velocities (2–1000 cm/s). , These larger ice spheres were found to approach a CoR of 0 at much lower impact velocities than what was found here for these much smaller ice particles. This is expected because the CoR increases with decreasing particle size as a result of a size dependence in the yield strength property of the particle, as described in a study of submicron-diameter tin particle impacts . The overall CoR trend of these micron ice particles is similar to that reported for submicron tin and also polystyrene latex spheres. , …”

“…The TICD and CAT, shown in Figure 2, were previously described in the literature studies. 22,23 With this assembly, the accelerated ice grains were detected traveling through the TICD electrodes before impacting the molybdenum CAT, where they induced a signal characteristic of the impact behavior (rebound, sticking, or fragmentation). These characteristic traces will be described in more detail in the Results and Discussion.…”