View
47
Download
2
Category
Preview:
DESCRIPTION
Physics on synchrotrons and computers. Alojz Kodre Faculty of Math & Physics, University of Ljubljana. X-rays. l = 0,01 - 10 nm n = 3.10 16 – 3.10 19 Hz h n = 100 eV – 200 keV. Wilhelm Röntgen, 1896,. Ljubljana, July 2011. Synchrotron storage ring. DORIS, DESY Hamburg. - PowerPoint PPT Presentation
Citation preview
Ljubljana, July 2011
Physics on synchrotrons and computers
Alojz Kodre
Faculty of Math & Physics, University of Ljubljana
X-rays
Wilhelm Röntgen, 1896,
= 0,01 - 10 nm = 3.1016 – 3.1019 Hz
h = 100 eV – 200 keV
Ljubljana, July 2011
Synchrotron storage ring
beam e+
path 289.2 m
W 4.45 GeV
= W/m0c2 8690
c - v c/22 ~ 2 m/s
T = o/v ~ 1 s
I 120 mA
Np = I·T/e0 1012
p ~ 6 · 10-10 mbar
N/V = pNA/(RT) ~104/(mm)3
Nf/t 1010 s-1
DORIS, DESY Hamburg
Ljubljana, July 2011
Synchrotron -
an extremely bright source of UV and X-ray light
Ljubljana, July 2011
DESY, Hamburg
Ljubljana, July 2011
Elettra, Trieste
Ljubljana, July 2011
ESRF, Grenoble
Ljubljana, July 2011
Brightness of different light sources
Ljubljana, July 2011
X-ray diffraction on crystalls:information on the distribution of atoms in the material
Ljubljana, July 2011
Protein Structure by X-Ray Diffraction
Protein –a molecule of ~ 10.000 atoms
Diffraction pattern of the protein
.
Ljubljana, July 2011
X-ray diffraction on disordered materials provides almost no structure information
Ljubljana, July 2011
Absorption spectroscopy
Monochromatic
x-ray beam
Io I d
d0I I e
Ljubljana, July 2011
energy
scattering Compton
scattering
Rayleigh
absorption
rela
tive
abso
rptio
n c
oeff
icie
nt
Ljubljana, July 2011
X-ray absorption
Ljubljana, July 2011
Absorption edges
0 5 10 15 20 25 300
20
40
60
80L
3 L2,1
K K L1 L2 L3Z
E (keV)
4 6 8 10 120
200
400
600
800
ZnCu
NiCo
FeMn
CrV
[
cm2 /g
]E [keV]
Ti
Cu K edge
0 2 4 6 8 10 120.0
0.4
0.8
1.2
L1-L
3 edges
K edge
Cu
[M
ba
rn/a
tom
]
E [keV]
8800 9000 9200 9400 9600 9800 100000.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0 XANES
Cu
d
E (eV)
8800 9000 9200 9400 9600 9800 10000
0,4
0,6
0,8
1,0 Cu
Cu
dE [eV]
Ljubljana, July 2011
Zn K edge – experiment and model
Ljubljana, July 2011
9660 9680 9700 9720 97400,0
0,5
1,0
1,5
2,0ZnO K-edge
measured calculated
/ 0
E[eV]
Ar
3180 3200 3220 3240 3260 32800
1
2
3
4
5
1s 3s->nl n'l'
1s 3p->nl n'l'
1s->p
1s->5p1s->4p Ar
d
E [eV]
3210 3220 3230 3240 32502,8
2,9
3,0
3,1
Ar
d
E [eV]
Ljubljana, July 2011
Metal-vapor cells
Ljubljana, July 2011
Cd vapor : metal
26600 26800 27000 27200 27400 276000.0
0.2
0.4
0.6
0.8
1.0
1.2 Cd para Cd listic
K
E [eV]
26800 27000 27200
1.00
1.04
26720 26740 26760 26780 26800 26820
0.98
1.00
1.02
1.04
[1s4p]5p2
[1s4p]5p
[1s4p]
[1s4d2]4f
[1s4d]5p
[1s4d]
[1s5s]
[1s5s]6s
[1s5s]5p[1s5s]6s5p
E [eV]
26700 268000
1
2 Cd dekonv. Cd para
Ljubljana, July 2011
Iodine
33200 33250 33300 33350 33400
1.01
1.02
atomic gel gel-autobk
K
E [eV]
atomicgelspline
33200 33300 33400 33500 336000.95
1.00
I atomic
vapor 950 oC solid
K
E [eV]
atomskipare 950 ºCtrden
atomicvapour 950 °Csolid
Ljubljana, July 2011
Atomic absorption Ga-Kr
50 100 150 200 250 300 350
0
2
4
6
8
10
[1s3d]..
[1s3p]..
Kr
Br
Se
As
Ge
Ga
/ K
[%
]
E [eV]
0
2[1s3d]4d
/
K [
%] 0
1
[1s3p]4p[1s3p]5p
0
4
Ga Ge As Se Br Kr
[1s3d]4p
EXAFS – Extended X-ray Absorption Fine Structure
2
022
KEEm
k
constructive interference
destructive interference
Rh
23000 23500 24000 24500 25000 25500 26000
0,5
1,0
1,5
2,0
2,5Rh
Ab
so
rptio
n
E (eV)
0 1 2 3 4 5 6 7 8 90
20
40
60
80
100
120
140
160
Rh
FT
ma
gn
itu
de
R [Å]
4 6 8 10 12 14 16 18 20
-0,05
0,00
0,051st shell
(k)
k ( Å-1 )
4 6 8 10 12 14 16 18 20
-0,01
0,00
0,01 2nd shell
(k)
k ( Å-1 )
4 6 8 10 12 14 16 18 20-0,02
-0,01
0,00
0,01
0,02
3rd shell
(k)
k ( Å-1 )
4 6 8 10 12 14 16 18 20
-0,01
0,00
0,014th shell
(k)
k ( Å-1 )
MoSI nanowires
Ljubljana, July 2011
0 1 2 3 4 5 60,00
0,02
0,04
0,06
0,08
FF
T(*
k)
[arb
it.
u]
r [Å]
I edge data model
0 1 2 3 4 5 60,00
0,05
0,10
0,15
0,20
0,25
FF
T(*
k) [
arb
it. u
]
r [Å]
Mo edge data model
SrTiO3
0 2 4 6 8 10 12 14 16-20
-10
0
10
20
30 300 K 84 K
k3 *(k
) [Å
-3]
k [Å-1]
0 1 2 3 4 5 6 7 80
4
8
12
16
20 300 K 84 K
FT
[ar
bit.
u.]
r [Å]
Ljubljana, July 2011
New devices
wiggler
undulator
rentgenski laser
Ljubljana, July 2011
DESY, Hamburg
PETRA
XFEL – X-ray Free Electron Laser
Ljubljana, July 2011
The group at Hasylab
Recommended