Neutron Research at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research
Total Page:16
File Type:pdf, Size:1020Kb
Neutron research at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research A.V.Belushkin On behalf of the FLNP Joint Institute for Nuclear Research Frank Laboratory of Neutron Physics FLNP is established in 1956 soon after the foundation of JINR. Scientific activity is focused on : - nuclear physics, - condensed matter physics - applied research. Il’ya Mikhailovich Fedor L’vovich Shapiro Frank 1915 – 1973 The IBR-2 high flux 1908 – 1990 Deputy director in 1959 pulsed reactor is the FLNP Director in 1957 – 1988. – 1973. basic facility. Nobel Prize 1958. The permanent staff is around 370 persons. Joint Institute for Nuclear Research The world’s first pulsing reactor Operation started 23.06.1960. At present decommissioned. Joint Institute for Nuclear Research IBR reactor was efficiently used for solving nuclear physics problems, ca. measurements of total and differential neutron cross-sections for different isotopes, parameters of neutron resonances, energy levels of exited nuclei, etc. Observation and investigation of properties for the -decay of neutron resonances. Study of the (n,p), (n,) reactions at thermal and resonance energies for nuclear reaction models, nuclear astrophysics. From 1965 – up to now. Experiments at: IBR-30, IBR-2, EG-5 (JINR, Dubna), VVR-reactor (INP, Kiev), ORELA (Oak Ridge), LANSCE (Los Alamos). Investigation of the parity violation effects in the (n,p), (n,) reactions. 1985-1995 yrs. Experiments at the VVR-M reactor (PNPI, Gatchina). Study of the (n,p), (n,) reactions at fast neutrons. 1995 – up to now. Experiments at EG-5 (JINR, Dubna), EG-4.5 (Peking University) Measurements of neutron cross sections. Experiments at IBR-30 (JINR, Dubna). Investigation of parity violation effects in neutron- nucleus interactions. Experiments at: IBR-30, IBR-2 (JINR, Dubna) Search for negative p-wave neutron resonances in Pb. Experiment at IBR-2 (JINR, Dubna) Joint Institute for Nuclear Research Neutron Reactor IBR-2 is operating since 1984 D. Blokhintsev Pulsed reactor with neutron flux 1016 n cm-2 s-1 N. Dollezhal and I. Frank Joint Institute for Nuclear Research IBR-2 – fast pulsing reactor Source: IAEA-TECDOC-1439, February 2005 Joint Institute for Nuclear Research IBR-2 – fast pulsing reactor Joint Institute for Nuclear Research HRFD – high resolution Fourier YuMO – small angle scattering diffractometer spectrometer REMUR – reflectometer with DN-12 – diffractometer for studies of polarized neutrons microsamples under extreme conditions Joint Institute for Nuclear Research Investigations of Nanosystems and Novel Materials by Neutron Scattering Methods • Physics of Nanosystems Fe (3-5 нм) Сr (1-2 нм) • Structure and Dynamics of Functional Materials • Complex Liquids and Polymers • Molecular Biology and Pharmacology • Structure of rocks and minerals • Neutron Nanodiagnostics • Engineering Diagnostics Joint Institute for Nuclear Research Main results achieved in condensed matter physics at FLNP JINR for last 7 years Microscopic origin of Experimental determination Structural physical phenomena in of universal constant of reorganization of complex oxides: interaction of random mitochondria under fluctuating surfaces osmotic pressure Lamellar • Colossal magnetoresistance, packing • Insulator-metal transition, d • Multiferroic phenomena, • Charge and orbital ordering Hexagonal packing Joint Institute for Nuclear Research Main results achieved in condensed matter physics at FLNP JINR for last 7 years Determination of residual stresses in the vessel of 1000 MW VVER-1000 reactor 400 1. FEM calculation: Model 1: , 300 y z Model 2: y 2. Austenite phase: 200 , , x y z 3. Ferrite phase: 100 y BIOLOGY MEDICINE FARMACOLOGY 0 Stress, MPa -100 -200 Ferrite Austenite interphase boundary atX=8 mm -300 Joint Institute0 10 for Nuclear20 Research30 40 50 X, mm Nanosystem GeO2-Eu2O3-Ag: Effects of clusters formation on optical properties 95GeO -5Eu O 94,9GeO -5Eu O -0,1Ag 2 2 3 2 2 3 o Silver doping effect To=350 oC To=350 C Increasing of luminescence intensity To=800 oC To=800 oC ~1000 times 0.01 0.1 0.01 0.1 -1 q, -3 1.5x10 Т =550 0С Experimental o 1.2x10-3 methods 9.0x10-4 95GeO -5Eu O -4 2 2 3 p(r), arb.units 94,9GeO -5Eu O Crystal structure Nanostructure 6.0x10 2 2 3 -0,1Ag 3.0x10-4 Ag X-Ray Small angle 0.0 0 50 100 150 doping diffraction neutron scattering r, Å The breakage of clusters because of the formation of Eu-O-Ag bonds. An increase in the intensity of luminescence excitation lines 7 5 Joint Institute7 for Nuclear5 Research 3+ F0 L6 (~395 nm) and F0 H6 (~318 nm) of Eu Studies of magnetic nanostructures by polarized neutron reflectometry c) Laterally patterned magnetic films a) Exchange coupled d) Ferromagnetic films on superlattice with anti- antiferro-magnetic ferromagnetic ordering substrates with exchange (e.g. GMR and TMR bias through common systems) interfaces b) Dilute magnetic e) Spring magnets semi-conductors as consisting of a top soft spin-injectors in magnetic layer exchange semiconductor coupled to a magnetically heterostructures hard layer. Huge decrease of electrical resistance under the influence of magnetic field ! A commercial IBM giant magneto resistive read head Joint Institute for Nuclear Research Magnetic off-specular reflection of polarized neutrons from multilayers Cr/Fe TU Muenchen (Germany), ILL (France), PNPI RAS (Russia), FLNP-JINR qx q Scheme of qz k pf p ki i experiment Fe i f f Cr f, rad Found magnetic structure as a function of depth. Twisted canted states in exchange- coupled multilayers are induced by a magnetic field applied. Neutron wavelength, Å Scattering pattern from sample 57 [ Fe(67Å)/Cr(9Å)]12/Al2O3, H=200 Oe Joint Institute for Nuclear Research Soft matter and biology From simplicity to complexity Neutrons Atoms & molecules Self organization Folding & aggregation Structure Dynamics & function Joint Institute for Nuclear Research • Producing of energy (ATP) for cellular processes. • Participating in ageing and apoptosis (programmed cell death). • Mitochondrial dysfunctions are causes of several diseases (muscular dystrophy, diabetes, Parkinson's and Alzheimer's diseases ). Inner mitochondrial membrane- location of energy generating system of mitochondrion • phospholipidic bilayer • transport proteins • respiratory chain components • ATP-syntase Joint Institute for Nuclear Research Hypotonic media induces changes in mitochondrial function: regulates the oxidation of fatty acid and other substrates. induces the rising of rate of the electron Normal condition Normal Isotonic transport through the respiratory chain Formation of “dried crista” Changes in function rising of rate and efficiency of ATP sythesis structural changes in polyenzymatic complex of oxidative phosphorilation switching on the local coupling regime imitation of hormone effect on mitochondria. amplitude - Hypotonic Low swelling Joint Institute for Nuclear Research Extracted interference peak Hypotonic conditions Scheme of dried Expanded disordered cristae ordered cristae formed under No peaks hypotonic conditions Krasinskaya I. et al. // Biokhimija 1989, V. 54: 1550-1556. Murugova T. et al. // Biophysics 2006, V.51: 882–886. Joint Institute for Nuclear Research SANS curves for rat heart mitochondria. Appearance of structural peaks as a result of order of mitochondrial inner membrane. d=220Å Measuring time by two detectors simultaneously 5-20 min. Ordered Lamellar phase with distance space 220 Å T.N. Murugova et al. // Crystallography Reports, 2007, V.52. P. 521–524. Joint Institute for Nuclear Research Formation of 3D structures inside mitochondria Switching on the volume regulation system in mitochondria induces the following structural changes: Rat heart mitochondria: from ordered lamellar (220 Å)– to another ordered packing (presumably hexagonal phase with spacing parameter 280 Å) Heart mitochondria Hexagonal packing -1 1.0 0.0276 Å 10 ) c 0.5 0.0550 Å-1 Modification of the mitochondria Iexp - (a+aq - Iexp -1 1 0.0 packing under osmotic pressure 0.02 0.04 0.06 0.08 0.10 q, Å-1 Intensity, cm Intensity, a = 250 Å 0.1 A 0.01 0.1 q, Å-1 -1 0.3 0.0266 Å 10 0.2 -1 +b) 0.0464 Å c 0.1 I exp - (aq - exp I -1 1 0.0 0.02 0.04 0.06 0.08 0.10 q, Å-1 Intensity, cm Intensity, 220 Å 0.1 d B 0.01 0.1 Lamellar packing q, Å-1 Joint Institute for Nuclear Research Engineering diagnostics 0.28 0.25 0.2 I0n I10n1.45 0.15 I15n1.05 I20n1.3 0.1 0.05 0 0 2.15 2.155 2.16 2.165 2.17 2.15 d0 d10d, d15 Å d20 d 2.175 Neutron diffraction peak layout of The experiment shift due to residual stress “…On basis of these results ПП80НВ.00.006 type striker made of 20X2H4A steel with surface cementation treatment was implemented in ПП80НВ perforator’s production. Application of this steel provide 2.5 times gain in mean time to failure: for 65C2BA steel mean time to failure is about 40 hours Equipment for mining industry while for 20X2H4A steel this value was increased up to 100 hours.” Sample 1 Sample 2 The measured residual stress distribution in the sample along radial coordinate x. Joint Institute for Nuclear Research “Nuclear Physics with Neutrons: Fundamental and applied studies” Main results, achieved during Highlights past 7 years Verification of the equivalence • Experiments with Ultra-Cold Neutrons principle for the neutron (UCN) n E mod • Studies of nuclear fission and other neutron- induced reactions H Free fall acceleration for the neutron Is the same as for macroscopic bodies • Study of the fundamental laws and within the accuracy 2 10-3 symmetries in neutron-nucleus interactions E mgH