On the heating of the ultracold neutrons by the sound vibration of the trap walls.

Interaction of ultracold neutrons with liquid surface modes as a possible reason for neutron energy spread during long storage in fluid wall traps

Concerning a Gas of Ultracold Neutrons in a Trap

Unconventional trapping of ultracold neutrons

Low-energy heating of ultracold neutrons during their storage in material bottles

Vibration-Induced Loss of Ultra-Cold Neutrons in a Magneto-Gravitational Trap

Observation of heating of ultracold neutrons as the cause of the anomalous limitation of their confinement time in closed vessels