An experimental investigation of the free decay of quantized turbulence in isotopically pure superfluid4He at mK temperatures is discussed. Vortices are created by a vibrating grid, and detected by their trapping of negative ions. Preliminary results suggest the existence of a temperature-independent vortex decay mechanism below T approx. 70 mK.
Davis, S. I., Hendry, P. C., & McClintock, P. V. E. (2000). Decay of quantized vorticity in superfluid4He at mK temperatures. Physica B: Condensed Matter, 280(1–4), 43–44. https://doi.org/10.1016/S0921-4526(99)01442-8