SCATTERING OF NEUTRONS AND X-RAYS k i k i - k f = q hω ENERGY TRANSFER hq MOMENTUM TRANSFER k f Dynamic structure factor O r , t COHERENT INCOHERENT SCATTERING SCATTERING g (r ,t) g s (r ,t) QUASIELASTIC DIFFUSIVE MOTIONS INELASTIC VIBRATIONAL COHERENT INCOHERENT STRUCTURAL FT [g s (r , )] NUCLEAR PROB. DISTRIBUTION ELASTIC Elastic Quasielas tic Inelastic Energy transfer, ω Δω e Δω qe S (q ,ω) = e i(ωt-q ·r ) g(r ,t) dr dt
SCATTERING OF NEUTRONS AND X-RAYS. hω ENERGY TRANSFER h q MOMENTUM TRANSFER. k i - k f = q. k f. k i. COHERENT INCOHERENT SCATTERING SCATTERING g ( r ,t) g s ( r ,t). . - PowerPoint PPT Presentation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
SCATTERING OF NEUTRONS AND X-RAYS
ki
ki - kf = qhω ENERGY TRANSFER
hq MOMENTUM TRANSFERkf
Dynamic structure factor
O
r,t
COHERENT INCOHERENT
SCATTERING SCATTERING
g (r,t) gs(r,t)
QUASIELASTIC DIFFUSIVE MOTIONS
INELASTIC VIBRATIONAL
COHERENT INCOHERENT
STRUCTURAL FT [gs (r, )]
NUCLEAR PROB.
DISTRIBUTION
ELASTICElastic
QuasielasticInelastic
Energy transfer, ω
Δωe
Δωqe
S (q,ω) = ei(ωt-q·r) g(r,t) dr dt
Neutron Diffraction
1) Scattering from nuclei- combined x-n analysis of small molecules.
2) Scattering power does not depend on atomic number.- hydrogens scatter strongly- deuterium and hydrogen opposite signs.