Investigation of storage of ultra-cold neutrons in traps

¹ Institute Laue-Langevin, 38042 Grenoble Cedex 9, France
² Petersburg Nuclear Physics Institute, 188350 Gatchina, Russia
³ Joint Institute for Nuclear Research, 141980 Dubna, Russia
⁴ Rutherford Appelton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK and Institute of Nuclear Research and Nuclear Energy, Sofia, Bulgaria

Corresponding author: nesvizhevsky@ill.fr

Received: 20 March 1998
Revised: 15 December 1998
Accepted: 4 February 1999
Published online: 15 May 1999

Abstract

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