The influence of low-frequency oscillations on the storage time of ultracold neutrons

The influence of the low-frequency spectrum of solids on the heating of ultracold neutrons (UCN) per single interaction with the wall is reported. It is shown that the anomalously short storage time in traps can be explained by UCN heating if there are clusters near the surface of the solid matter, vibrating at a frequency of 1010Hz. The comparison with the experimental data of the measurements of the heat capacities of disordered solids carried out at low temperatures permit to make the conclusion that the clusters should be of about 70 to 80 A. The influence on the UCN heating of other possible low-frequency vibrations inside the solid matter is considered as well