230 likes | 392 Views
Magnetic neutron wave guides for optical devices. Frédéric OTT 1 , Sergey KOZHEVNIKOV 1,2 1 Laboratoire Léon Brillouin, CEA Saclay, France 2 Frank Laboratory of Neutron Physics, JINR, Dubna, Russia. Magnetic neutron wave guides for neutron optical devices. ILL Annual Report
E N D
Magnetic neutron wave guides for optical devices Frédéric OTT1, Sergey KOZHEVNIKOV1,2 1Laboratoire Léon Brillouin, CEA Saclay, France 2Frank Laboratory of Neutron Physics, JINR, Dubna, Russia
Magnetic neutron wave guides for neutron optical devices • ILL Annual Report • F. Pfeiffer, V. Leiner, P. Høghøj, I. Anderson Optical index Soft magnetic layer Guiding layer (with low optical index) Pinned magnetic layer substrate
Combination : dynamics and wave-guides • Magnetic traps Allows the neutron beam to freely enter the guide Acts like a guide
Samples • Sputtering setup in LLB, Saclay, France Py(10-20nm)/Ti70/Py50/float_glass 25×30×2 mm3 Py20nm/Al(20-80)/Py50/float_glass 55×55×2 mm3
Simulation of neutron wave function • SimulReflec available at http://www-llb.cea.fr/prism/programs/simulreflec/simulreflec.html F. OTT (LLB) Mode 3 Mode 2 Mode 2 Mode 1 Mode 1
Fitting of experimental data (HADAS, FZJ) =4.7 Å 1 2 3 2 3 1
Off-specular fitting Program for fitting HADAS data (E. Kentzinger, FZJ, Juelich) Parameters: - angle between vectors of external magnetic field and magnetization - dispersion of magnetization direction // - structural in-plane correlation length - perpendicular correlation length - roughness d – domain size M – magnitude of magnetization
X-rays off-specular reflection Py20Ti70Py50nm/FG =1.57 Å
PRISM -scan • PRISM, =0.42 nm
Working plan in 2006 • Treatment of experimental data (X-rays specular and off-specular reflection, REFLEX, EROS, PRISM reflectometers) • Preparing of experiment on guiding effect in new samples with Al guiding layer (September 2006, REFLEX, Dubna, Russia) • Publication of methodical paper on different representation of off-specular neutron scattering • Preparing of paper on off-specular reflection experiments
Conclusions • Wave guiding effect at off-specular reflection have been measured in magnetic and non-magnetic samples • It is necessary to modify models for fitting experimental data • There are experimental difficulties for observation of guiding effect from the exit of film: small value of effect, wide angular distribution of guided intensity, influence of resolution and background • New samples with Al guiding layer have been manufactured