観測ロケットS-520-28号機を用いた微小重力下における宇宙ダストの核生成実験の概要

Abstract

We performed microgravity experiments of homogeneous nucleation of iron from the vapor phase using the sounding rocket S-520-28 on December 17, 2012. The purpose is determination of a sticking probability of iron during the nucleation from the supersaturated vapor, because the sticking probability is one of the most uncertain physical quantities to understand the formation process of cosmic dust based on nucleation theories. We prepared the specially designed Mach-Zehnder-type interferometers with an evaporation chamber and camera recording systems to fit the space and weight limitations of the rocket. Three same systems, named DUST 1 to 3, were installed into the rocket. Iron was evaporated in an argon gas and then it was cooled and nucleated to form nanoparticles. The temperature and concentration of iron vapor at the nucleation site are determined from the movement of the interference fringe. Here, we present the brief summary of the experiments and the preliminary results of the homogeneous nucleation from iron vapor under microgravity.