Investigation of storage of ultra-cold neutrons in traps

It is known that losses of ultra-cold neutrons (UCN) from traps are due to the beta-decay, up scattering and absorption on a surface but we have ident ified for the first time a complementary mechanism. We suppose that this ar ises from an increase in energy of the neutrons resulting in an upper energ y spectral cut-off which is about twice higher than that for initial stored neutrons. The total probability for such a process equals similar to 10(-5 ) per collision with a trap wall made of stainless steel without or with a Fomblin oil and grease coating.