micro-xrf - max planck society · 1.basics 2.x-ray optics 3.application examples 4.discussion....
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Birgit Kanngießer
fEdEs critcap )(2)( θ+=
© T. Wolff et al., submitted
Energy dependency of spot size
Polycapillary optics
Birgit Kanngießer
© T. Wolff et al., submitted
Energy dependency of transmission
Polycapillary optics
air
opticL
I
IeT airair ρµ−=
Birgit Kanngießer
Micro XRF Spectrometer
µ-focu
s X-ra
y tube
SDD
CCD camera
polycapillary
lens
+ laserpointer for allignment
Tabletop Spectrometers and Portable Spectrometers
• Conventional Tubes
• Microfocus Tubes
• Monocapillaries
• Polycapillaries
• Crystals, Multilayer
• Si(Li)- and HPGe-Detectors
• Drift chambers
Synchrotron Spectrometers
• Synchrotron Radiation
• + Compound Refractive Lenses
+ Cryodetectors
Birgit Kanngießer
Investigation of historical manuscripts and compositions
written with iron gall ink.
Assignment of
single sheets, corrections, amendments,
to authors or to certain periods of genesis
by Nondestructive analysis of
minor constituents in iron gall inks with Micro-XRF.
B. Kanngießer, W. Malzer, O. Hahn
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
Experimental set-up:
A portable spectrometer is important tomeasure on site in the archives and museums!
Portable technique:• drift chamber detector, capillary lens• helium flooding for light elements• spot size ~ 100 µm
Flexible, non-destructive investigations!
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
• Considerable variance of the count rate due to the fibrous structure and inhomogeneity of the paper
∀ → An area of at least 10 x 100x100 µm2 is measured
Investigation of Historical Manuscripts and Compositions
relative standard deviation [%] as function of the number of measurements
0
10
20
30
40
50
1 2 3 4
Reihe1
Reihe2
Reihe3
Reihe4
Reihe5
K
Ca
Mn
Fe
Zn
201051
Birgit Kanngießer
Parameter:
Spot size ca. 100 µm
30 W Mo-tube
45 kV, 600 µA
Accumulation: 100 s (lt)
5 10
100
1000
10000
I /co
unts
E /keV
ink paper
f.103v:
black browish
iron gall ink on
rag paper.
Investigation with Micro X-Ray Fluorescence Analysis
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
0,0 0,2 0,4 0,6 0,8
0,0
0,1
0,2
0,3
0,4
f.15 schwarz f.15 braun f.20 braun f.22 braun f.24 braun f.28v braun f.34 schwarz f.34 braun f.38 schwarz f.38 braun
[Zn
]/[F
e]
[Cu]/[Fe]
Ratio of the Cu to Zn intensities, without taking the fluorescence of the paper into account. Linear relationship?
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
0 2000 4000 6000 8000 10000
0
2000
4000
6000
8000
10000
12000
14000
Blatt 224
WZ99 übrige
Zn
[Cou
nts]
Cu [Counts]
Ratio of the Cu to Zn intensities: The linear relationship is due to brass tools („Holländer“) for the paper manufacturing!
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
-0,2 0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4
0,0
0,2
0,4
0,6
0,8
1,0
1,2
[Zn]
/[Fe]
[Cu]/[Fe]
0,0 0,2 0,4 0,6 0,8 1,0 1,20,0
0,1
0,2
0,3
0,4
0,5
[Cu]/[Fe]
Re.
Häu
figk
e it
Ratio of the Cu to Zn intensities The paper background is just subtracted from the ink.
No simple additive relation for the fluorescence from the ink and the paper!
Additive assumption: ca. 35% of the samples have Cu-intensities ≤ 0.
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
Papercontamination: Fe, Cu, Zn, K, ...Fibers of approx. 10 - 20 µm diam.
Inkmain component: Feminor components: Cu, Zn, K, ...
w1
0 z
paperink
dI dm dp
QIIQpm,
QIm
Qpp
ρIm= ρI (1-∆z/dm)
Linear decrease of the ink density in the paper
Model
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
takes into account
• the paper background
• the thickness of the ink layer
• the diffusion of the ink into the paper
The fingerprint value W
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
light brown brown
dark brownFolio 38 of Mozart‘s Zauberflöte
Visual inspection:three types of ink have been used
Investigation with µ-XRF:
0.00
0.02
0.04
0.06
ZnMnCu
W =
Kiw
i/KFe
wFe
→ Two types of ink can be identified
Mass depositon in mg/cm2:
light brown: 0.6 (may be diluted brown) brown: 3 dark brown: 0.7
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer Further development : improvement of reliability and error analysis
Investigation of manuscripts of J.W. GoetheFragment of Faust II
0,0 0,2 0,4 0,6 0,8 1,0
0,0
0,2
0,4
0,6
0,8
1,0 0,0
0,2
0,4
0,6
0,8
1,0
[Zn]/[Fe] [Cu]/[Fe]
(a) Faust I (a) Faust I, amendments (b) Faust I Faust II
[Mn]/[Fe]
Fragment of Faust I
original
amendment
original
Goethe (1749 – 1832)
Goethe- und Schiller-Archiv, Weimar
Fragment of Faust II
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
Absolute quantification is not necessary!A fingerprint which characterises the content of minor constituents is sufficient
To distinguish two specimen• a quantitative fingerprint is necessary• a knowledge of the uncertainty is desirable
µ-focu
s X-ra
y tube
SDD
CCD camera
polycapillary
lens
+ laserpointer for allignment
Investigation of Historical Manuscripts and Compositions
Birgit Kanngießer
Literature:
• B. Beckhoff, B. Kanngießer, N. Langhoff, R.Wedell, H. Wolff (eds.), “Handbook of Practical X-Ray Fluorescence Analysis”, Springer-Verlag ISBN 3-540-28603-9, (2006)
• B. Kanngießer, “ Quantification Procedures in Micro X-ray Fluorescence Analysis ”, Spectrochimica Acta B 54 /4, 605-609, (2003).
• W. Malzer, O. Hahn, B. Kanngießer, “A fingerprint model for inhomogeneous ink paper layer systems investigated with micro x-ray fluorescence analysis“, X-Ray Spectrom. 33, 229-233 (2004).
• O. Hahn, W. Malzer, B. Kanngießer, B. Beckhoff, “Characterization of iron gall inks in historical manuscripts and music compositions using x-ray fluorescence spectrometry“, X-Ray Spectrom. 33, 234-239 (2004).