Measurement of fragments generated by hypervelocity impacts of micron-sized iron particles at grazing incidents

Abstract

• Fragments of hypervelocity dust impacts are measured using a Delay Line Detector. • Majority of fragments created at grazing incidences are composed of dust projectile. • Fragmentation of projectiles increase with impact speed for grazing incidences. • The fragment speeds are distributed around 80% of the projectile impact speed. In this study, we present results from hypervelocity impacts of iron particles onto smooth surfaces under shallow incidence. For the first time, the submicron fragments of the projectiles were measured using a delay-line detector combined with a multichannel plate. Micron-sized spherical iron particles with speeds between 4–40 km/s are fired by a dust accelerator facility and impact on an optical mirror target at grazing angles of 2 ° , 4 ° , and 6 ° from the horizontal. Individual fragments generated in each impact event have been measured and analyzed including their speeds, masses, and trajectories. The total mass and momentum of fragments are comparable to their parent projectile. It is observed that most fragments have speeds exceeding 80 % of pre-impact velocities. Fragments generated at incident angle of 2 ° leave the target surface with even lower elevation angles of around 1 ° . The majority of impact fragments generated under incident angles of 4 ° and 6 ° form a spatial distribution centered an axis of 5 ° elevation, which increases with increasing impact speed. Furthermore, azimuthal scattering occurs with a distribution concentrated within ± 10 ° .