Experiment and Estimation Procedures of a Very-Small External Force Acting on an Electrostatically Levitated Object

Abstract

We established a Free Drift (FD) method to remotely measure the force generated on an isolated object simulated using an Electrostatic Levitation Furnace (ELF). The FD method can be applied in high power laser ablation experiments, where the electric charge of the sample changes drastically during the irradiation. The analyses to deduce the thrust are described in detail. Using this method in the ELF on the International Space Station (ISS), we successfully measured the thrust generated by laser beam irradiation to an Al droplet for the first time. The momentum coupling coefficient (Cm ) when irradiated by a laser beam with a laser power density of 103 -104 W/cm2 was around 10-9 N/W.