Characterization of the High Velocity Impact Phenomena of Small Water-Ice Particles
Abstract
For the success of future life finding missions to ocean worlds like Enceladus, terrestrial characterization of mission-relevant instrumentation is key. The Cassini mission previously observed small (~1 μm) ice particles in the plume of Enceladus and characterized these particles using impact ionization mass spectrometry. The particles and the molecules entrained in them were subjected to impacts at hypervelocity speeds. The objective of our work is to investigate the effect of hypervelocity impact on grain fragmentation, and the potential for subsequent molecular fragmentation. The Aerosol Impact Spectrometer (AIS) is an instrument that can produce analogues to particles previously observed from Cassini, accelerate a single particle to the high velocities relevant for a fly-by spacecraft (> 3 km/s), and analyze their impact phenomena on metal targets. Electrospray ionization (ESI) is used for the generation of 0.5-2 μm, highly charged water-ice particles. Individual grains are accelerated under high vacuum (10-8 Torr) with a 41-stage linear accelerator (LINAC) to a desired final velocity from 0.01 to 5 km/s. The implementation of this LINAC with ice particle source and its capabilities will be overviewed. The impact phenomena, including rebound, sticking, and fragmentation, of the accelerated particles on a metal target are characterized with a tapered image charge detector (TICD). We found that 850 nm-sized grains at lower velocities (< 880 m/s) demonstrate velocity-dependence in their post impact behavior, including sticking and fragmentation of the grain. Ongoing studies will further elucidate impact phenomena at higher velocities. Future studies using ice particles containing organic and inorganic solutes will examine the post-impact mass spectra using a time-of-flight mass spectrometer to allow examination of molecular fragmentation of the solutes at hypervelocity.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA181.0009B
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0317 Chemical kinetic and photochemical properties;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0343 Planetary atmospheres;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0399 General or miscellaneous;
- ATMOSPHERIC COMPOSITION AND STRUCTURE