5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Basis HFR IBR-2 user policy collaboration
Project REMUR: Investigation of the structure of nano-objects in films of magnetic and nonmagnetic materials including new Larmor precession devices
Project Spin-Echo: Feasibility study of time-of-flight spin echospectrometer at IBR-2.
Project EPSILON/SKAT: Investigation of strain/stress and texture on geological samples
Project YuMO: Investigation of nano - and mesostructures via small-angle neutron scattering
Neutrons at IBR-2
User meeting, June 2004, at FLNP/JINRProjet leader meeting, October 2004, at Uni Goettingen
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Project DN-12: Neutron studies of microsamples under high pressure
Project FSD: Internal stresses in functional materials studied by the high resolution Fourier neutron diffraction technique
Project: DAQ and CI - Development of Data Acquisition Systems and Computing Infrastructure for the IBR-2 spectrometer complex.
Project: Gas Neutron detectors
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Advanced Reflectometry with Larmor Precession
Nanoscience Biology Horizontal Reflectometer Angular and Energy Encoding
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
stripe arrays
Nano-structures: needs for nano-characterization
imbedded nanoparticlesin polymer matrix
magnetic multilayer films
MONITORING of theINTERNAlL STRUCTURE
in VARIOUS NANOSYSTEMS
multilamellar vesicles for biochemical applications
buried quantum dots
Nanowires in mesoporous silica
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Nano-structures “as seen” by neutrons
MONITORING of theINTERNAlL STRUCTURE
in VARIOUS NANOSYSTEMS
multilamellar vesiclesfor biochemical applicationsstripe arrays
imbedded nanoparticlesin polymer matrix
magnetic multilayer films
buried quantum dots
Information about the transverse and lateral structure (magnetic and non-magnetic) is encoded in the 2D scattered intensity -> comprehensive data analysis is needed
Nanowires in mesoporous silica
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Sample
Precession magnetic fields (solenoids)
Polarizer(supermirror,
Heusler)
Polarization analyzer
Detector
1B
2B
,S Q
0P
2L1L
1v
2v
outP
11 1 1
1L
Lt B
v
The principle of Neutron Spin Echo
22 2 2
2L
Lt B
v
1 1 2 21 2
1 2NSE
B L B L
v v
1B
P L LB
2B
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
1L
The principle of Neutron Spin Echo1P
2L1
Sample
,S Q
1
1
1
v
v
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Larmor precession angle
LlH/vn
L=2.916 kHz/Oe
Larmor precession for encodingLarmor precession for encoding and and
vn
Sample position outside (s1) or inside (s2) LP-device
n
polarizedneutrons
S1S2
Magnetic field H
l
Current sheetsDetector Analyzer
(s1) sensitive to and and (s2) H perpendicular to P; scattering f(M)(s3) divergent incoming beam for GISANS
Pulsed white beam
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Reflected
Direct
Det. Analyzer Sample LP-device Res. spin flipper
Reflected beam
Direct beam
H
Encoding of Encoding of with with LPLP-device-device
Top view
Polymerfilm sample
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
*direct and reflected beams in phase*Spin-asymmetry SA = (I+-I-)/(I++I-)
H = 20Oel = 0.473m
Encoding of Encoding of with with LPLP-device-device
spin up
Det. Analyzer Sample(after LP) LP-device Res. spin flipper
Reflected beam
Direct beam
H
H=18.8 Oederived from oscillations
Polymerfilm sample
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Encoding of Encoding of with with LPLP-device-device
Det. Analyzer Sample LP-device Res. spin flipper
Reflected beam
Direct beam
H
H=18.8 Oe H=17.5 Oe
Polymerfilm sample
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
SA for H=17.5 Oe SA for H=17.5 Oe and H=18.8 Oe
SA (H=17.5 Oe) - SA(H=18.8 Oe)
Encoding of Encoding of as a function of H as a function of H
Polymerfilm sample
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Reflected
Direct
Det. Analyzer Sample LP-device Res. spin flipper
Reflected beam
Direct beam
H
Encoding of Encoding of with with LPLP-device--gain in intensity-device--gain in intensity
Top view
Polymerfilm sample
Incoming converging beamOverlapping but encoded signal
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Reflectometry with Larmor precessionReflectometry with Larmor precession
Det. Analyzer LP-device Res. spin flipper
Reflected beam
Direct beam
HSample
Fe-Cr sample - “AF” ordered -near remanent field
Fe-Cr multilayer sample inside LP-device
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Out-of-plane (and in-plane) Larmor precessionOut-of-plane (and in-plane) Larmor precession
M1
M2
Simultaneous measurement with in-plane and out-of-plane spin directionAccess to out-of plane magnetisation and full depth profile of in-plane magnetisation
Determination of the total magnetic moment and its directionDetermination of the layer-by-layer magnetization
magnetization
spin rotation axis
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Advanced Reflectometry with Larmor Precession
Angular and Energy Encoding for Nanoscience REMUR equipment including neutron guide and cold moderator Reflex equipment (cold moderator) Biology-Horizontal Reflectometer
Note:Study for investigation of 3rd co-ordinate (GISANS)
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Advanced Reflectometry with Larmor Precession
V.Lauter-Pasyuk TU MünchenW.Petry TU MünchenM.Jernenkov ILL GrenobleH.J.Lauter ILL Grenoble
A.Ioffe FZ JülichT.Brückel FZ Jülich
P.Schmiedel Uni Halle
K.Jernenkov FLNP DubnaV.Bodnarchuk FLNP DubnaA.Petrenko FLNP DubnaV.Aksenov FLNP DubnaA.Belushkin FLNP Dubna
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Top view of IN3 with spin echo option ZETA
B
Heusler analyzer
sample area
3He detector
Heusler monochrom.
double RF-flippers(bootstrap coils)
mumetal shield
monitor counter
PG-filter
couplingcoils
1 m
Residual internal field ~ 5 mG.
„Precession“ length - 55 cm
Frequency range 50 – 750 KHz corresponds to effective fields 35 G – 1 KG
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
Three axis spectrometer IN3 with spin echo option ZETA.The magnetic shields are opened to show the two flipper coils in each arm
double RF-flippers(bootstrap coils)
5th workshop on scientific collaboration/JINR/Dubna 17-19.01.05 HJL
, coscos( ) ,outNSEzP dQ R QQd S
What does Neutron Spin Echo measure?
( , ) is probability of a neutron being scattered with energy change and momentum transfer S Q Q
cosine FT of ( , ) with respect of .outzP S Q
L. Van Hove, Phys. Rev. 95, 249, (1954)
, ,Re Reoutz NSE
NSEi iQRP d S Q dR G Re e
3( , ) ( , ) ( , ) iQRNSE NSEI Q d R r t r R t e
, , , density-density correlation function NSE NSEG R r t r R t
0 12
outd z
II P
Re ( , )outz NSEP I Q
22
0
For example:
( , ) ; ( )outz NSE NSE NSE
NSES Q P LBe
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