LEVITAS: Levitodynamics for Accurate Individual Particle Sensing in Space

TL;DR

LEVITAS is a novel in-situ sensor using levitated nanoparticles to detect and analyze individual particles in rarefied space environments with high sensitivity and precision.

Contribution

The paper introduces LEVITAS, a new levitodynamics-based sensor capable of measuring properties of particles in extremely sparse media, extending sensing capabilities in space environments.

Findings

Simulated detection of particle impacts in space conditions.

Estimated medium properties like density, velocity, and composition.

Potential for measuring high-velocity neutral gas particles from interstellar space.

Abstract

Accurately observing the rarefied media of the upper atmosphere, exosphere, and planetary and solar system environments and beyond requires highly sensitive metrological techniques. We present the operating concept and architecture of an in-situ sensing solution based on the dynamics of a levitated nanoparticle (levitodynamics). It can detect and measure impacts of individual particles in rarefied media. Dubbed `LEVITAS', our sensor consists of a dispenser of dielectric nanoparticles and optical trapping of a single nanoparticle in the focus of a laser beam. The trapped nanoparticle constitutes a harmonic oscillator at frequencies in the kilohertz range whose position can be tracked at the standard quantum limit by interferometric detection of the laser photons it scatters. Here, we simulate microcanonical impacts on the nanoparticle and show that the density, velocity, temperature, and composition of the surrounding medium can be estimated accurately. We illustrate the performance of LEVITAS in circumstances ranging from low Earth orbit out to exospheric distances, across which individual impacts can be detected at favourable rates. Furthermore, LEVITAS may be employed to accurately measure highly rarefied neutral distributions within vastly different areas of momentum space. This we demonstrate by simulating the measurement of high-velocity neutral gas particles from the interstellar medium penetrating the heliosphere and flowing through our solar system.