Abstract View
Aerosolization of Fine Lunar Simulant Particles for Size and Charge Characterization and Low-Cost Sensor Calibration
ABHAY VIDWANS, Shruti Choudhary, Brad Jolliff, Pratim Biswas, Washington University in St Louis
Abstract Number: 296
Working Group: Instrumentation and Methods
Abstract
In the Apollo manned lunar missions, lunar dust posed a great challenge. Electrostatic forces dominate transport of these dust grains, overcoming gravitational forces and leading to migration and adhesion to nearby surfaces. As upcoming manned lunar missions for extended human residence on the moon are being planned (ARTEMIS III), it becomes increasingly important to understand the characteristics of the fine content of dust that upon inhalation could adversely affect health. Studies on Apollo samples show that fine particles account for less than 20% by weight (1), but nearly 100% by number. While the fine particulate content of lunar regolith has been studied (2), little attention has been given to the fines of lunar simulant, a widely used Earth-sourced resource on which most of the lunar dust research has been performed.
In this study, we aerosolize JSC-1A simulant and use aerosol instrumentation to comprehensively examine the size, shape, and charging characteristics of fine particles in real time. Size distributions show unimodal shape with a mode in the realm of 0.2 to 0.3 µm. SEM imagery of these fine particles show highly irregular shape, consistent with lunar regolith. Tandem-DMA charge characterization indicates that nearly 100% of particles become charged when aerosolized, and the charge distribution is very widely spread across multiple charges. Next, calibration experiments were performed with the aerosolized simulant to evaluate the performance of two miniature low-cost sensors (Sharp GP2Y1010AU0F and Applied Particle Technology MINIMA). The two sensors, with different theories of operation, were calibrated against a Federal Reference Method PM monitor. Preliminary results show positive correlations for particle concentration. Further development of these sensors may enable in-situ concentration and size distribution measurements on the lunar surface.
[1] Carrier, W. D. (1973). Lunar soil grain size distribution. The moon, 6(3-4), 250-263.
[2] Greenberg, P. S., Chen, D. R., & Smith, S. A. (2007). Aerosol measurements of the fine and ultrafine particle content of lunar regolith.