Neutral Excitation Seen In Superfluid Helium
DOI: 10.1063/1.3035011
Two Berkeley experimenters report they have produced a new kind of energetic neutral excitation in superfluid helium that travels centimeters without scattering. Clifford M. Surko and Frederick Reif, writing in Phys. Rev. Letters 20, 582 (1968) speculate that they are seeing an excited helium atom. If their interpretation is correct, the experiment is an interesting combination of atomic and low‐temperature physics.