Objetivo The surprising phenomenon of small (~10?-7?eV) energy change of UCN in traps was discovered recently by groups participating in the present project. The main objective of the project consists in understanding the nature of this effect. The probability of such small change in energy is 10?-7?-10?-4? per collision with Cu, Be, stainless steel, or fomblin oil surfaces. The probability of events with increase in energy is at least 10 times higher than that with energy decrease. The process differs from normal up-scattering to thermal energies (~0.025eV at room temperature) but the result is that higher energy neutrons can escape in the bulk of material by the known processes of up-scattering and absorption or penetrate through the trap wall if it is thin enough. The probability for these additional losses from traps is rather high. This makes them especially important for surfaces with low probability for normal losses: the small-energy heating is responsible for a significant fraction of the losses at the surface of fomblin oil and for at least 10% of the anomalous losses in beryllium traps. Only the lower limit can presently be estimated because the measuring device was sensitive only to a part of the spectrum of scattered neutrons.Among other results, this project would allow a serious progress in the high-precision gravitation spectroscopy of UCN providing an almost ideal performance of the method. This would give us universal and powerful tools for other UCN studies. A detailed study of the new process would also provide the knowledge about the conditions and/or materials, which would allow suppressing or/and controlling it in UCN experiments. The experimental elimination of the decrease in UCN storage times by small energy changes may then be used to improve these experiments. Simultaneous suppression of the effects of small energy changes and of standard up-scattering would lead to the best possible UCN storage times in traps. Finally, there is very good hope that the proposed project will reveal the nature of the recently discovered phenomenon of rare events of small UCN-energy change in traps Programa(s) IC-INTAS - International Association for the promotion of cooperation with scientists from the independent states of the former Soviet Union (INTAS), 1993- Tema(s) 1A - Nuclear Physics, Astronomy, Astrophysics OPEN - OPEN Call Convocatoria de propuestas Data not available Régimen de financiación Data not available Coordinador Institute Laue-Langevin Aportación de la UE Sin datos Dirección 6 rue Jules Horowitz 38042 Grenoble Francia Ver en el mapa Coste total Sin datos Participantes (3) Ordenar alfabéticamente Ordenar por aportación de la UE Ampliar todo Contraer todo Joint Institute for Nuclear Research Rusia Aportación de la UE Sin datos Dirección Jolio Curie,6 141980 Dubna, Moscow Region Ver en el mapa Coste total Sin datos Russian Research Center "Kurchatov Institute" Rusia Aportación de la UE Sin datos Dirección Kurchatov square 1 123182 Moscow Ver en el mapa Coste total Sin datos Technische Universität München Alemania Aportación de la UE Sin datos Dirección James-Franck-Strasse 85748 Garching bei München Ver en el mapa Coste total Sin datos
