Interaction between charged dust particles and plasma on super-fluid liquid helium surface

将带负电荷、质量密度大于液氦（LHe）的微米级粒子落在LHe表面。在这里，尘埃颗粒和LHe表面被热灯丝或rf等离子体发射的电子所充电。这些粒子的电荷被发现比在室温下测量的要小。此外，在LHe表面施加强向上电场（~几kV/cm），建立了LHe表面附近有悬浮粒子的体系。

Micron-sized particles with negative charge and larger mass density than liquid helium(LHe) were dropped onto the LHe surface. Here, dust particles and LHe surface were charged with electrons emitted from a hot filament or an rf-plasma. The charge of those particles was found to be smaller than those measured at room temperature. Furthermore, a system with floating particles near the LHe surface was established by applying strong upward electric field(～a few kV/cm) on the LHe surface.