Absolute measurement of the total ion-drag force on a single plasma-confined microparticle at the void edge under microgravity conditions

摘要

We present an absolute measurement of the total ion-drag force on one single microparticle at the edge of thendust free region in low pressure complex plasmas: the void. In order to do so, the particle confinement positionnwas monitored as a function of the gas pressure for two particle sizes under normal gravity conditions and undernmicrogravity conditions during parabolic flights. At the border of the void, the ion-drag force on a particle withna radius of 4.90 μm appeared to be (3.6 ± 0.3) × 10−12 N.