Keywords: helium 4

  • Lack of Oscillatory Motion of Superfluid ⁴He During its Dripping from a Needle

    Although pendant droplets commonly exist in our daily lives, their dynamics are not fully understood. To obtain further understanding of its physics, we observed superfluid helium dripping from a thin needle by a high-speed camera. Superfluidity is an inviscid liquid state only happening in helium at low temperatures. The present study where we used a thin needle to eliminate the droplet’s remnant volume clearly demonstrated that the dissipation-less large oscillation observed in the previous experiments was crucial for the discretization of the dripping period which is novel phenomenon reflecting the anomalous fluid properties of superfluid helium.