Ve. Varlamov et al., OBSERVATION OF THE PENETRATION OF SUBBARRIER ULTRACOLD NEUTRONS THROUGH BERYLLIUM FOILS AND COATINGS, JETP letters, 66(5), 1997, pp. 336-343
The subbarrier passage of ultracold neutrons through beryllium foils a
nd coatings with a probability much higher than that of tunnelling is
observed. This effect may be responsible for the so-called anomalous l
oss of ultracold neutrons. (C) 1997 American Institute of Physics.