Project leader : Yu . V . Nikitenko (FLNP, CMD) Team :

1. NTC – 06.06.2018, PAC – 14.06.2018Isotope-identifying neutron reflectometry (IINR)at IBR-2M reactor ( 2015-2018) Project leader:Yu.V. Nikitenko (FLNP, CMD) Team: N.A. Gundorin, Yu.M. Gledenov,Yu.N. Kopach(FLNP, NPD) A.V. Petrenko,V.D. Zhaketov (FLNP, CMD), V.L.Aksenov(FLNP) Content • 1. IINR • 2. Results: • Equipment • Testing

2. Reflectometry at REMURchannel 8 of IBR-2M

3. Structures and regimes of neutron wave field • Potentials: U = V-iW,V = 2 ħNisotb/m , W = (ħ /2)Nisotv • W = (ħ2/2m)(klim, im)210-4-10-2 V, (klim, im)2 = (m/ħ)Nisotv • Neutron cross-sections: = abs+ nc+diff+inel • First radiation - Rexp(q)  [V(z),W(z)]  n(z, q) • Second radiation - Jisot(q) =А  n(z,q) Nisot(z) dz • Isotope spatial distribution Nisot(z) !

4. What gives the IINR ?

5. Tasks of project • 1.Creation of three registration channels of secondary radiation, namely, charge particles, gamma-quants and spin-flipped neutrons • 2. Modernization of existing measurement modes: Magnetic regime, Low temperatures, Low scattering structures

6. Charge Particle Channel (1) sample position with goniometer, turning electromagnet, small and large ionization chambers

7. Gamma Channel (2)collimator, gamma-detector and anti-compton crystalls with multiplayers

8. Gamma Channel (2) Platform elements, electromagnet poleselectromagnet turning device, collimatorin FLNP workshop

9. Gamma Channel (2) : HPGe Detectoron base of high clear germanium with preamplifier and high voltage filter Low background carbon capsulediameter 83 mm Energy range 3 keV - 10 MeV Technical parameters at nitrogen cooling: - registration efficiency of line 1,33 МэВ 45 % - energy resolution ofline 5,9 keV 0,8 keV of line 1,33 MeV2,0 keV ratioPeak/Compton (including option Damage RepairNDR) 60:1

10. Gamma Channel (2) : Anti-comptonprotection of gamma detector Eight NaJ crystalls with photomultipliers and preamplifiers

11. Spin-flip channel (3)magnetand 125 supermirrors of neutron polarization analyzer

12. Spin-flip channel (3)Analyzer inside of protection block Full assembly of protection block

13. Map of neutrons (0) and charge particles (1) intensities for V(65 nm)/CoFe(5nm)/ 6LiF(5 nm)/V(5 nm)

14. Intensity(a) and normalized intensity (b) dependencies for structure Cu(10 nm)V(55 nm)/CoFe(5nm)/ 6LiF(5 nm)/V(15 nm)/glassof reflected neutrons (1) and charge particles (2)from neutron wavelength at glancing angle 3 mrad a)

15. Spin Neutron Reflectivities (3 channel) for V(65 nm)/CoFe(5nm)/ 6LiF(5 nm)/V(5 nm) (a) andCu(10 nm)V(55 nm)/CoFe(5nm)/ 6LiF(5 nm)/V(15 nm)(b)

16. Charge particle intensityfor structures Cu(10 nm)V(65 nm)/CoFe(5nm)/6LiF(5 nm)/V( 5 nm)/glass(1) andCu(10 nm)V(55 nm)/CoFe(5nm)/ 6LiF(5 nm)/V( 15 nm)/glass(2)1= 3.25 Å, 2= 3.45 Å

17. Experimental dependencies of normalized intensity of tritons (1, 2) and spin-flip neutrons (3, 4) forstructuresV(20 nm)/CoFe(5nm)/6LiF( 5 nm)/V(15 nm)/glass(1, 3) andV(20 nm)/CoFe(5nm)/6LiF( 5 nm)/V(5 nm)/glass(2, 4).

18. Finalscientific results Spatial Sensitivity of charge part. channel (CPC(1)) z(d= 5 nm,1 hour, =945 barn)=0.9Å Spatial Sensitivity of spin-flip channel (SFC(3)) z(d= 5 nm, 1 hour, angle (B^H)=70degr.)=0.7 Å Amplitude Sensitivityof CPC min(t=10 hours, d= 5 nm,z =1nm)1barn Maximal Amplitude Sensitivity of CPC min(t=10 hours, d= 5 nm,z =1nm)0.07 barn Spatial Resolution of CPC with glass reflector(m=0.65) 5 nm Maximal Spat. Resol. of CPC(Supermirror Refl., m=8.0) 0.4 nm

19. Financial Expenses • а) Electronics for ionization chambers – 30 k$ • b) Germanium detector – 80 k$ • c) Materials: Plumbum – 1400 kg – 3 k$, Bismuth – 400 kg – 6 k$), Boron polyethylene – 40 k$ , Still – 20 k$ • d) Detectors of anticoincidence scheme for germanium detector – 30 k$, memory electronics -15 k$ • e) Neutron detector and analyzer protection – 50 k$ • f) Polarizer analyzer – 75 k$ • g) Manufacturing works at FLNP – 26 k$ • k) Testing structures – 5 k$ Total: 390 k$ (overrun on 90 k$ before planned) Financial sources JINR budget – 265 k$ (Romanian contrib. 20 k$) RFFI scientific project – 125 k$

20. Publications Previous demonstration of Neutron Standing Wave Regime through the secondary radiation (1998-2000) • 1.В.Л. Аксёнов, Н.А. Гундорин, Ю.В. Никитенко, Ю.П. Попов, Л. Чер, P3-98-374, Dubna, JINR, 1998, 8 с. • 2. В.Л. Аксёнов, Н.А. Гундорин, Ю.В. Никитенко, Ю.П. Попов, Л. Чер. Surface. Rentgen, Synchrotron and Neutron Technique, 6 (2000) 7. • 3. V.L. Aksenov, L. Cser, N.A. Gundorin, Yu.V. Nikitenko, Yu.P. Popov. Physica B 276-278 (2000) 809. • 4. V.L. Aksenov, Yu.V. Nikitenko, F. Radu, Yu.M. Gledenov, P.V. Sedyshev, F.V. Petrenko, S.V. Kozhevnikov, E3-98-383, Dubna, JINR, 1998, 6p. • 5. V.L. Aksenov, Yu.V. Nikitenko, F. Radu, Yu.M. Gledenov, P.V. Sedyshev. Physica B 276-278 (2000) 946. • 6. V.L. Aksenov, Yu.V. Nikitenko, Physica B 267-268 (1999) 313. -------------------------------------------------------------------------------------------------------- IINR project (2015-2018) 1. Ю.В. Никитенко, А.В. Петренко, А.Н. Гундорин, Ю.М. Гледенов, В.Л. Аксёнов, IINR at IBR-2, Kristallography, 2015, v. 60, №4, 518. 2. В.Д. Жакетов, А.В. Петренко, С.Н. Вдовичев, В.В. Травкин (ИМС, Н.Новг.), А. Csik(Hungary),Ю.Н. Копач, Ю.М. Гледенов Е. Сансарбаяр, А.Н. Гундорин, Ю.В. Никитенко,В.Л. Аксёнов Neutron spectrometer in glancing geometry with registration on neutrons and charge particlesDirected to “Surface, Rentgen,Synchrotron……” 3. It is prepared an article for “Nuclear Instrument Methods”

21. Final Remarks • The project is successfully completed:at REMUR are created new three channels of secondary radiation and two channels of them are tested already. Gamma channel will be tested in this autumn. • Nuclear physics and condensed matter departmentsof FLNP showed brief together a work Because successful realization of the project FLNP proposes to close the project Thank you very much for attention