Photophoretic forces on chondrules in drop tower experiments

Abstract

Studies of meteoritic and cometary materials give evidence for radial mixing of solid material within the early solar system. Among other transport mechanisms, photophoresis is a proposed mechanism for radial material transport in protoplanetary disks. Within this study, the photophoretic motion of chondrules in microgravity is investigated in drop tower studies. Chondrules form the meteorite Bjurböle were exposed to an intense laser beam. The acceleration due to photophoresis was observed and tracked with two cameras. The experimental results give evidence that photophoresis indeed is an efficient transport mechanism for chondrules and other small particles in the solar nebula. The measured values for the photophoretic force correspond well to the results of earlier studies and show clearly, that the models for particle transport by photophoresis are in agreement with the experimental data.