Ice Grain Accelerator with Charge Detection Mass Spectrometry

NASA has need for laboratory simulations of high velocity impacts with ice particles in order to test in-situ instruments intended for sampling material from planetary bodies such as comets and the water ice plumes of Enceladus. Specifically, beams of micrometer-size water ice grains moving in vacuum at speeds of 5 km/s or higher would be very useful. Light gas guns produce showers of high velocity ice grains that are not well controlled or well characterized, and are not easily combined with the sensitive instrumentation to be tested. Free jet molecular beam sources cannot reach velocities much greater than 2 km/s. The goal of the phase I effort is to develop and characterize an in-vacuo electrospray generator of highly charged ice grains suitable for controlled electrostatic acceleration to hyper-velocities. We will characterize the mass, charge, and speed of the ice grains using RadMet’s existing charge detection mass spectrometer hardware. The six-month effort will establish the feasibility of producing ice grains with suitable size and charge inside the vacuum chamber and develop strategies for combining the ice grain source with high voltage accelerating potentials in phase II.