e/Ultracold neutrons

Information
has gloss	eng: Ultracold neutrons (UCN) are free neutrons which can be stored in traps made from certain materials. The storage is based on the reflection of UCN by such materials under any angle of incidence.
lexicalization	eng: Ultracold Neutrons
instance of	(noun) an elementary particle with 0 charge and mass about equal to a proton; enters into the structure of the atomic nucleus neutron