1 "The Ultra Cold Neutrons – an everlasting challenge" Egor Lychagin Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

2 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

3 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

Sir James Chadwick 1932 Discovering of neutron... while the usual solutions may remain in the vessels, unfortunately there are no vessels capable keep the neutrons Y. B. Zel’dovich, "Storage of cold neutrons", Soviet Physics JETP, vol. 9, p. 1389, 1959 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Fast Intermediate Resonance Thermal Cold Ultracold  2dsin(  )=n d Bragg’s low: Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER THREE BASE FACILITY : IBR-2 Pulsed Reactor IREN facility (Intense REsonance Neutron sourse) based on linear accelerator EG-5 Van de Graaff accelerator

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER Average power, MW2 Pulse repetition rate, Hz5 Pulse half-width, µs: fast neutrons thermal neutrons Thermal neutron flux density from the surface of the moderator*: - time average - burst maximum~ n/cm²·s ~ n/cm²·s IBR-2 Pulsed Reactor 2500 hours/year IBR-2M on the world scene

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER IREN facility Peak current (A)3 Repetition rate (Hz)50 Electron pulse duration (ns)100 Electron energy (MeV)30 Beam power (kW)0.4 Multiplication1 Neutron intensity (n/s) hours/year

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER EG-5 The characteristics of EG-5 Accelerator: Energy region: 0.9 – 3.5 MeV Beam intensity for +: 30 μA Beam intensity for +: 10 μA Energy spread < 500 eV Number of beam lines: 6 Electrostatic Van de Graaff accelerator, as one of basic experimental facilities of Frank Laboratory of Neutron Physics was built in hours/year

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER Our facilities cover wide neutron spectrum Ultacold Cold Thermal Resonance Intermediate Fast IBR-2 IREN EG Outside JINR

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER FLNP activities: – Neutron nuclear physics; – Condensed matter physics; – IREN Project; – IBR-2 spectrometers developing

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER THREE MAIN DEPARTMENTS: Department of nuclear physics (94 persons) Department of Neutron Investigations of Condensed Matter (86 persons) Scientific and Experimental Department of Complex of IBR-2 spectrometers (41 persons)

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER Nuclear fission Fundamental Applied Fundamental symmetries In neutron induced reactions Ultracold neutrons Highly excited states of the nuclei Neutron activation analysis Fundamental properties of the neutron Neutrons in space Development of IREN Neutron nuclear physics Ion beam analysis

14 S N S N S N S N S N H Effective potential~ eV Gravity:~ eV / Meter Magnetic field:~ eV / Tesla Potential of interaction of slow neutrons with matter : Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

15 UCN losses at collisions: VacuumMatter 1 Å Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

16 V  5 m/c 20 km/h  500 Å 50 nm E  eV T  K Typical dimensions of viruses You might overtake them by bike if you will try ~1 m 1 cm ~1.02  neV Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

17 Number of elastic reflections from surface up to !!! (theoretically up to 10 6 ) They could be observed for a long time in local space Typical materials and its parameters: MaterialE lim, cmV lim, m/s  *10 -4 (300 K) Stainless still Copper Glass Aluminum Fomblin oil Be DLC Sapphire It could be trapped! In a trap UCN behave as cold ideal gaz Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Registration of UCN Gaz detector with 3 He Thin foil with low U lim (Al) Acceleration in the Earth gravitational fieldUpscattering to the thermal region Polyethylene Gaz detectors of thermal neutrons Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

K 300 K Reactor Active Core Moderator UCN Today more power sources provide accumulation about 1÷20 n/cm 3 in traps Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

F.L. Shapiro 1968 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

F.L.Shapiro, V.I.Luschikov, A.V.Strelkov, Yu.N.Pokotilovskii 1969 Lushchikov V. I., Yu.N.Pokotilovskii, A.V.Strelkov, F.L.Shapiro. JETP Lett (1969) IBR 1kW only 1 neutron per 100 seconds ! Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

22 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Neutron life time (electroweak interaction theory) Neutron EDM (T-invariance) Neutron wave properties (quantum mechanics, theory of relativity) Surface investigations … Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

24 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

Important input parameter for tests of the Standard Model of the weak interaction (Testing of unitarity of quarks mixing matrix ) Necessary to understand matter abundance in the Universe Necessary to calibrate Neutrino Detectors and to predict event rates Neutrino detectors: Parameters Strength: G F Quark mixing: V ud Ratio: = g A /g V Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Storage experiments with UCN “counting the surviving neutrons”  0 ( extrapolation )  0 ( experiment ) N(t 1 )N(t 2 ) “UCN bottle” Two relative measurements Two absolute measurements nβnβ “counting the dead neutrons” e N0N0 l Beam experiments with cold neutrons Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

“Bucket” experiment 1992 JINR – PNPI  n = ± 3.3 s Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Filling of trap  =180  Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Monitoring  =30  Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Emptying  =40  Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Emptying  =50  Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Emptying  =180  Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

PDG tau = (880.3+/-1.1) s 2014 PDG tau = (880.3+/-1.1) s 2007 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

The situation is not clear yet. Is very important to perform an experiment with an accuracy about 0.1 seconds and with a minimum of systematic errors Modern situation (data from PDG) Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Current projects for neutron life time measurement: BeamUCN trapping NIST (USA)NRC KI PNPI (Russia) Fomblin oil NRC KI PNPI (Russia) Magnetic trap ILL (France) Magnetic trap NCSU (USA) Magnetic trap TUM (Gemany) Magnetic trap Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

38 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

A permanent electric dipole moment of a fundamental particle violates both parity (P) and time reversal symmetry (T). In framework of SM |d n | ~ 10 –32 e·cm Beyond Standard Model: |d n | ~ 10 –26  10 –26 e·cm nEDM is very sensitive probe for Physics beyond SM Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

From presentation of Philip Haris, US Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

From presentation of Philip Haris, US Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

From presentation of Philip Haris, US Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Precision of the measurements: Best results: Phys. Rev. Lett. 97, (2006) T=130 sec E=10 kV/cm Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

I f neutron were the size of the Earth... xx -e +e... current EDM limit would correspond to charge separation of  x  10  Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Current projects for neutron EDM measurement: 1.NRC KI PNPI (Russia) 2.SNS (USA) 3.PSI (Switzerland) 4.TUM FM-II (Germany) 5.KEK TRIUMF (Canada) Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

46 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

Classical case when H Quantum case when V.I.Luschikov, 1976 V.I. Luschikov and I.M. Frank Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

2002 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

A 2nd-generation gravitational neutron spectrometer GRANIT GRANIT collaboration: ILL France LPSC France JINR Russia LPI Russia MSIURussia PNPIRussia URIUSA UVa, USA LMAFrance Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

A 2nd-generation gravitational neutron spectrometer GRANIT Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

A 2nd-generation gravitational neutron spectrometer GRANIT Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

A 2nd-generation gravitational neutron spectrometer GRANIT Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

A 2nd-generation gravitational neutron spectrometer GRANIT The phenomenon of gravitational quantum states of neutrons could be used in various applications, as apriory it provides a very « clean » system with well-defined quantum states. -Constrains for short-range forces; -Constrains for axion-like forces; -Constrains for neutron electric charge; -Non-commutative quantum mechanics; -Neutron quantum optics effects; UCN reflectometry; -Constrains for a logarithmic term in the Schrödinger equation; -Loss of quantum coherence; UCN extraction, transport, tight valves; -Study of thin surface layers; -Nature of gravity; -Physics beyond the Standard model Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Searching of sources of additional loses for materials with small capture (contradictions between theory and experiments for Be ~ 10 times, for oxigen ~100 times) Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Searching of sources of additional loses for materials with small capture (contradictions between theory and experiments for Be ~ 10 times, for oxigen ~100 times) Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

A.V.Strelkov, V.V.Nesvizhevsky, P.Geltenbort et al, NIM 440A(3), (2000) V.V.Nesvizhevsky, A.V.Strelkov, P.Geltenbort et al, ILL Annual Report 1997, p.62-64; Physics of Atomic Nuclear 62(5), (1999) Level of UCN gas per collision with wall VUCN - Vaporizing Ultra Cold Neutrons Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

neutron surface Interaction of neutrons with nanoparticles Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Two models for liquids: Nano-droplets V.Nesvizhevsky Surface waves S.K. Lamoreaux, P.A., R. Golub Question is open Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Could the observed phenomena explain the abnormal losses? In principle, yes. But dedicated experiment is needed to measure simultaneously total losses and all known channels of the losses. Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Fabry Perot interferometer for light and its quantum analog 1.A.A. Seregin, Sov. Phys. JETP 46 (1977), p M.I.Novopoltsev et al.NIM A. 264 (1988) P A. Steyerl, et al, PhysicaB 151 (1988) Bondarenko I.V., Frank A.I., Balashov S.N.et al. J.Phys. Soc. Jpn. 65(1996). Suppl. A. P.29. Quantum state 121 Substrate 2lcos(  )/ =m Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

mg=1.02 neV/cm Two FPIs with variable distance between them Detector Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

UCN diffraction by a moving grating E E y z V K L Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

Splitting of the spectrum A.I.Frank et al. ILL annual report 2001 Phys.Lett.A 311 (2003) 6 Phys.Lett.A 311 (2003) 6 Jetp Lett, 81 (2005) 427 Angular period of grating mrad (20μ at the middle diameter) Detector Monochromator grating Analyzer Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

H E0  EE0  E E E 0 + mgH E 0 – ħ  1 + mgH HH E 0 – ħ  2 + mgH The idea was to compare the change of energy mgH with energy ħΩ transferred to neutron by a moving grating g A.I. Frank, P. Geltenbort, M. Jentschel, et al. JETP Letters, 86, 225 (2007) Frank A.I., Masalovich S.V., Nosov V.G. (ISINN-12). E , 215, Dubna, (2004) Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

69 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

70 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER ±13978±0.8 Developing of experimental technic, of UCN sources, UCN detectors and etc. Search reasons of abnormal large losses of UCN from traps Research with UCN energy levels in gravitational field Discovering of hydrogen contamination of surfaces Discovering of UCN “small heating and cooling”

71 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.Huge losses for solid surfaces with small capture. Experimental losses 10 times large than theoretically predicted. These discrepancy are 10 times for Be and 100! times for solid O 2. We don’t know reason of these additional losses yet. 2.Detail investigation of possible systematic effect in neutron life time measurements and neutron electric dipole moment search. 3.Investigation of “small UCN upscattering”. 4.Small intensity of UCN sources.

Scientific program is traditional plus “new physics” Main task is to increase UCN density and flux It allow us to increase precision of experiments and develop new methods for surface investigation by UCN Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

73 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

First UCN sources ( ) JINR, Dubna JINR, Dubna 1.Kurchatov institute, Moscow 2.PNPI, Gatchina 3.RIAR, Dimitrovgrad 4.INP, Almaty 5.TUM, Munchen Current UCN sources (2014) 1.ILL, Grenoble, France 2.Mainz, Germany 3.Los Alamos, USA 4.KEK, Japan 5.J-park, Japan Next generation UCN sources (under construction) 1.PSI, Switzerland 2.ILL, Grenoble, France 3.SNS, USA 4.PNPI, Gatchina, Russia 5.TU-Munchen, Garching, Germany 6.J-Park, Japan 7.Triumph, Canada (in collaboration with KEK) 8.NCU, USA Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER Pulsed neutron sources?

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER Akhiezer A and I Pomeranchuk, "On the Scattering of Low Energy Neutrons in Helium II", J. Phys. USSR, 9 (1945), 461 Akhiezer A and I Pomeranchuk, "Scattering of Neutrons with Energy of Several Degrees in Liquid Helium II", JETP, 16 (1946), 396

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER UCN production rate: R = 4.55 · 10 −8 dJ/dλ (8.9 Å) cm −3 s −1 UCN accumulated density in the source:

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER WWR-M project He Т=1.2 К Pb Т=300 К Ф=10 14 n/(сm 2 с) Q=15 MW  UCN =10 4 сm -3 (  =10 с) Ф=4.5∙10 12 n/(сm 2 с) Ф( =9 А)=3∙10 10 n/(сm 2 с) Q He =6 W Al, Q Al =13 W C, Q C =700 W Pb, Q Pb =15 kW 19 W LD 2 Т=20 К C Т=300 К LD 2, Q LD2+Al =100 W

Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER Projects for PIK: Need cold source inside reactorDon’t need cold source inside reactor

79 Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER 1.What are ultracold neutrons? 2.How we can use UCN for physics? Examples Neutron life time measurement Neutron electric dipole moment search Neutron quantum states in Earth gravitational field. 3. What we have achieved and open problems. 4. New UCN sources. New proposal for helium source. 5. Conclusion

1.UCN is very interesting object and power tool for fundamental research. 2.Research with ultracold neutrons deal with different fields of physics. It allow as obtain very interesting and important physical results. 3.During almost 50 years in the experiments with UCN accumulate huge experimental experience; new phenomena was observed, new physical results was obtained. 4.To have breakthrough in the field it is need to develop and construct new powerful UCN sources. Russian research centers have good background and potential in the field still. 5.Reactors in the Gatchina have a chance to get more powerful UCN source in the world. Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

FLNP has a wide scientific program in UCN field. It concludes: Participation in GRANIT collaboration Small up-scattering investigation Investigation of UCN interaction with nanoparticles Participation in life-time measurements Quantum optics investigation with UCN Measurements of equivalence principle for neutron UCN sources developing We are welcome you to join us for further research Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER

82 Thank you for attention! Joint Institute for Nuclear Research FRANK LABORATORY OF NEUTRON PHYSICS SCIENCE BRINGING NATIONS TOGETHER