Micro-XRF€¦ · 2.X-ray optics 3.Application Examples 4.Discussion. Birgit Kanngießer Modern...

Micro-XRF:Principles, Methodology andApplications in CH Studies

Birgit Kanngießer

Birgit Kanngießer

Outline

1. Basics

2. X-ray optics

3. Application Examples

4. Discussion

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Modern X-ray optics

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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

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Application Example

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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

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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!


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• 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


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

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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


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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?


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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!


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-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.


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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


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takes into account

• the paper background

• the thickness of the ink layer

• the diffusion of the ink into the paper

The fingerprint value W


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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


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


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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


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).

Micro-XRF€¦ · 2.X-ray optics 3.Application Examples 4.Discussion. Birgit Kanngießer Modern...

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