Post on 02-Aug-2020
Photodetectors atPhotodetectors at «« Le LouvreLe Louvre »»XX--ray, ray, γγ--rayray andand visible visible spectrometries spectrometries
appliedapplied to to Art Art and Archaeologyand Archaeology issues issues
T. Calligaro, Centre de recherche et de restauration des musées de France
UMR 171 – Palais du Louvre
New Developments in Photodetection, June 21, 2002
Outline•• PresentationPresentation of of the the C2RMF C2RMF •• Examination Examination of of artifactsartifacts
•• Visible light, IR Visible light, IR reflectographyreflectography, UV fluorescence XR , UV fluorescence XR imagingimaging•• examplesexamples of application to of application to examinationexamination ofof paintingspaintings and and sculpturessculptures
•• Characterisation Characterisation of of materialsmaterials•• Introduction to Introduction to acceleratoraccelerator--based methods based methods •• Example Example of of detection detection of of fakes using chemical fakes using chemical compositioncomposition•• Example Example of of materials materials identification identification and determinationand determination of of
provenanceprovenance
•• Specific problemsSpecific problems•• Improvement Improvement of of the sensitivity the sensitivity to trace to trace elementselements•• Chemical environment with Chemical environment with HiHi--Res Res XX--ray ray spectrometryspectrometry•• Portable Portable detection systems detection systems for for onon--the fieldthe field analysisanalysis
Conclusions Conclusions and and prospectsprospects
Presentation of the Center for research and restoration of the
museums of France (C2RMF)
Belongs to the French Ministry of Culture Created in 1999 by the merging
of the laboratory and restoration centre
Laboratory
Founded in 1931 by 2 Argentinean physicians
Located in Paris under the Carrousel gardens of the Louvre
Staff ~70 : Culture (curators, engineers), CNRS, CEA
Associated with CNRS since 1996 – UMR 171
Location of the C2RMF
Missions of Missions of thethe C2RMFC2RMF
Diagnosis, short studies on art and archaeology works• acquisition (authentication)• restoration • exhibition
Long-term research• archaeometry : studies of ancient technologies and provenance• conservation science : understanding the artists techniques• preventive conservation : investigation of alteration process
Publishing and teaching
Main tools for examination and characterisation of cultural heritage
•• ExaminationExamination of of artifactsartifacts•• Visible light, IR Visible light, IR reflectographyreflectography, UV fluorescence , UV fluorescence •• XX--ray ray imagingimaging, , betagraphybetagraphy, , emissiographyemissiography•• Scanning Scanning electronelectron microscope (SEM)microscope (SEM) imagingimaging
•• Characterisation Characterisation of of materialsmaterials•• Structural Structural analysisanalysis : XRD, FT: XRD, FT--IR, Raman IR, Raman •• Inorganic chemical Inorganic chemical composition : IBA, XRF, SEMcomposition : IBA, XRF, SEM--EDXEDX•• OrganicOrganic composition :composition : ChromatographyChromatography, GC, GC--MSMS
•• DatingDating•• ThermoluminescenceThermoluminescence•• 1414C C using acceleratorusing accelerator--based based mass mass spectrometryspectrometry
ExaminationExamination of of works works of artof art
Paintings and Paintings and sculpturessculptures
Photography with direct and grazing light:evidence of the Van Gogh’s technique
in « Mademoiselle Gachet au jardin »
Ven
usG
enitr
ix1st
-2nd
AD
visible light ultraviolet
Venus Genitrix (detail)restored hand made in a different marble
Principle of infrared reflectography :access to the charcoal underdrawing
mid-rangeinfrared(1.8-2.5µm)
Raphael’s painting
Examination by infrared reflectography
Radiography studio for paintings
Radiography of the « Gobeur d’oursins » of Picasso (1946):painted on top of a portrait of Gal Vanderberg
Radiography
Examination of a Spanish painting from the XVIth centurydirect light grazing light
Spanish painting : UV fluorescence reveals restorations
visible light ultraviolet
Spanish painting :X-rays reveals a second character : part of a wider composition
Infrared Radiography
AnalysisAnalysis ofof material usingmaterial usingnonnon--destructive techniques:destructive techniques:
thethe case ofcase of acceleratoraccelerator--based methodsbased methods
Fundamentals Fundamentals of PIXE et PIGE of PIXE et PIGE methodsmethods((PParticlearticle IInducednduced XX--rayray EEmissionmission et et PParticlearticle IInducednduced γγ--rayray EEmissionmission ))
XX--rays rays γγ--r
ays
rays
Beryllium : 9Be(p,αγ)6Li 3562 keV
Lithium : 7Li(p,p’γ)7Li 477 keV
Fluorine : 19F(p,p’γ)19F 197 keVtarget atomstarget atoms
e-expelled electronexpelled electron
33--MeV MeV protonsprotons
acceleratoraccelerator
HPGe HPGe detectordetector Si(Li) Si(Li) detector detector
AAccelerateur ccelerateur GGrand rand LLouvre pour l’ouvre pour l’AAnalyse nalyse EElémentairelémentaire
22--MV tandemMV tandem acceleratoraccelerator«« AGLAEAGLAE »»
Control Control andand datadataacquisistionacquisistion roomroom
PIXE PIXE external beam setup and experimentalexternal beam setup and experimental conditionsconditionsProton Proton energyenergy : 3 : 3 MeVMeVBeam intensityBeam intensity : 2 nA: 2 nA
integratedintegrated dosedose : 0,25 : 0,25 µµC C --> no damage> no damagebeam diameter beam diameter on on the targetthe target : 20 : 20 µµmmbeambeam exit foil : 0.1 exit foil : 0.1 µµm m silicon nitridesilicon nitride
sample
L
H
�
�
He flow«« low energylow energy »»
L L --detectordetector«« high energyhigh energy »»
H H -- detector detector entranceentrancewindowwindow
0.25 0.25 µµmm boron boron nitridenitride
6 6 µµmm BeBe
absorberabsorber 1 1 µµmm carboncarbonHe atmosphereHe atmosphere
100 100 µµmmaluminumaluminum
energyenergy rangerange 0,6 0,6 -- 20 20 keVkeV 5 5 -- 4040 keVkeV
elementelementrangerange
matrixmatrixoxygenoxygen--ironiron
tracetrace elementselementscalciumcalcium--yttriumyttrium
solidsolid angleangle 1 1 msrmsr 100100 msrmsr
CloseClose--up of up of the external beam the external beam systemsystem
Target : Target : gemstonegemstone
Low energyLow energy XX--ray ray detector detector for major for major elementselements e.g. Al, Si…e.g. Al, Si…
HighHigh energyenergy XX--ray ray detector detector for trace for trace elementselements e.g. e.g. CrCr, , TiTi, V, , V, FeFe, , GaGa……
HPGeHPGeγγ--ray ray detectordetector
Helium Helium fluxflux
videovideo cameracamera
Charged particle Charged particle beam beam exitexit
Main Main featuresfeatures of of acceleratoraccelerator--based methodsbased methodsBenefitsBenefits•• non destructive non destructive analysisanalysis of of objects with any shape and objects with any shape and sizesize•• no no samplingsampling, no , no preparationpreparation ((conductiveconductive coatingcoating etc.)etc.)•• simultaneous measurement simultaneous measurement of a of a wide wide range of range of elementselements (10< Z < 92)(10< Z < 92)•• sensistivity sensistivity to trace to trace elementselements (down to (down to thethe µg/g µg/g levellevel))•• 30 µm30 µm33 probedprobed volume: volume: selectionselection of of detailsdetails•• truly truly quantitative quantitative methodsmethods•• elemental mapselemental maps (micro et (micro et macroscopicmacroscopic scalescale))
DisadvantagesDisadvantages•• no information about no information about thethe chemical chemical statestate•• no structural information (XRD, IR, Raman)no structural information (XRD, IR, Raman)•• nearnear surface (1 surface (1 –– 30 µm) (30 µm) (problems with altered objectsproblems with altered objects) ) •• expensive expensive large large scale facilityscale facility
First First application of application of thethe PIXE PIXE method method : : Indirect Indirect dating dating of of paintingspaintings
The The portrait of Bernard Palissyportrait of Bernard PalissyPainting suppossedly Painting suppossedly representing representing B. B. Palissy, French Palissy, French scientist and artist scientist and artist of of the the RenaissanceRenaissance
(1580(1580--1620)1620)
Proposed Proposed to to be be acquiredacquired by by the the French French museumsmuseums
First First application of application of thethe PIXE PIXE method method : : detectiondetection of of forgeriesforgeries
PresencePresence of CrPbOof CrPbO44 green pigment green pigment only introducedonly introduced after after 18501850
This This painting is probablypainting is probably a a forgeryforgery
Application of Application of thethe PIXE PIXE method method : : materialsmaterials identification identification and and provenanceprovenance
Ishtar’s eyesIshtar’s eyesStatuette Statuette exhibited exhibited in in thethe Louvre Louvre museummuseumDatedDated toto the Parthian periodthe Parthian period (1(1stst BC BC –– 22nd nd AD)AD)
LikelyLikely representingrepresenting Ishtar, Ishtar, the famous mesopotamian the famous mesopotamian mother goddessmother goddess
(Astarté or Venus)(Astarté or Venus)
DiscoveredDiscovered in 1863 in in 1863 in thethevicinityvicinity of of BabylonBabylon
The statuette is placed in the external beam system
PIXE PIXE spectra recorded spectra recorded on one on one eyeeye
X-ray energy (keV)
coun
ts
1
10
100
1000
10000
1e5
0 5 10 15 20 25
high energy X-ray detector spectrum
low energy X-ray detector spectrum
OK
Al K
Ti K V K CrK Fe K
Ga K
SriLankIndia 1
India 2
Burma
Cambodia
Thailand
Afghanistan
VietNam
Babylon
Map of Middle East and Asia : sources of rubies
Sri Lanka
Trace Trace element fingerprint element fingerprint of of rubies from rubies from Ishtar Ishtar and various depositsand various deposits
Iron(ppm)
Chr
omiu
m (p
pm) T T TTT
TT
TT
TT
T
TTT
V
V
VV
V
VVV
V
VV
KKKK
KK
MM
MM
MM
MM
MM
MM
MM
MM
M M
MM
B BB
B B
B
B
B
B BBB
B
B
B
BB
B
B
B
B
BB
B
B BB
B
B
B
BB
B
B BB
BB
B
BBB
BBB
B
BBB B
B
BBB
BBB
BBB BBB
B
BB B BBB
BB
B
BB
B
BB
BBB
B
B
B
BB B
BB
B BB
B
BB
B
BB B
BBBB
B
B
BBBBB
BB
B
B
B
B
BBBB BBB
BB B
BB B
BBBBB
BBBBB B B
BBBBBB
BBBBB B
BB B
B BB BB
BBBB
BB
B
BBBBB BB BB BBB
B
B
B
B B
B
B
B
B
BB
A
A
AA
A
A AA
AAA
A AAB
BB
TT
TC CCVVV
SS
S
MMM
II
II
II
I
II
III
BB
BBB
B
B
B
BB
B
B
BB
B
B
B
X XX
XB
XX
XX
SSSSSS
SS
SS
SS
S
S
SSS
S
SS
SS
SSS
SS
S SS
S
S
S SS
S
SS S
SS
SS
S
SSS
S
S
S
S
SS
S
SSS
S
S
S
S
SS
B
T
10
100
1000
10000
10 100 1000 10000
Statuette of Ishtar
group IBurmaVietnam A
group IIAfghanistanSriLankaVietnam B
group IIIThailandCambodiaKenyaMadagascarIndia
Proof of Proof of authenticityauthenticity of of the the statuettestatuette
Original report of Mr P. Original report of Mr P. DelaporteDelaporte, French consul , French consul at at BagdadBagdad
who discovered thewho discovered the statuettestatuetteDocument Document written at Hillahwritten at Hillah, , close to close to BabylonBabylon
JanuaryJanuary 21, 186321, 1863
Results
The eyes and the navel of Ishtar are not made of red glass, nor red garnets, as previously reported, but rather proved to be fine rubies.
According to the age of the statuette, this is the most ancient rubies found in Middle-East.
Evidence of a gem route between South-East Asiaand Mesopotamia during the 1st century BC.
The jewelsThe jewels ofof the first the first kingskings of Franceof France
SaintSaint--DenisDenis BasilicaBasilica ((northnorth of Paris)of Paris)cemetarycemetary ofof the kingsthe kings of Franceof France
since the Merowingiansince the Merowingian
paire of brooches 450-500 A.D
plaque-boucle 470-500 A.D
plaque « bull » 480-510 A.D
5-digits brooch~500 A.D
pair of brooch
500-520 A.D
2 disc brooches« reine Aregonde »
575-600 A.D
Quatrefoil brooch600-625 A.D
2 square brooches 500-550 A.D
TheThe garnetsgarnets
H = 6½ - 8½r = 3.5 - 4.3 g.cm-3
n = 1.78 - 1.89
Chemical composition of garnets A3
++B2+++ (SiO4)3
end-members
grossularAlCaouvaroviteCrCaandraditeFeCa
spessartiteAlMnpyropeAlMg
almandineAlFe
Actually garnets are a solide solution of end membersexample :
rhodolite = mixing of 50% pyrope / 50% almandin
Fe/Mg plot : three groups of garnets
Mg vs Fe
Fe (ppm)
Mg
(ppm
)
0
20000
40000
60000
80000
1e5
1,2e5
1,4e5
1,6e5
1,8e5
0 60000 1,2e5 1,8e5 2,4e5 3e5 3,6e5
Pyropes
Rhodolites
Almandins
Ca/Mg plot : 2 types of almandines
othersquatrefoil5 fingers brooch
MgO (ppm)
CaO
(ppm
)
0
10000
20000
30000
40000
50000
60000
70000
10000 30000 50000 70000 90000 1,1e5 1,3e5 1,5e5 1,7e5 1,9e5
almandines :
pyropes :types IV & V
rhodolites :type III
type I
type II
othersquatrefoil5 fingers brooch
MgO (ppm)
CaO
(ppm
)
0
10000
20000
30000
40000
50000
60000
70000
10000 30000 50000 70000 90000 1,1e5 1,3e5 1,5e5 1,7e5 1,9e5
almandines :
pyropes :types IV & V
rhodolites :type III
type I
type II
Yttrium content confirms 2 sources of almandines
eagle A5 fingerseagle Bbullquatrefoilkidneysquare Bsquare A3 fingers A3 fingers BArégonde AArégonde B
Magnesium (ppm)
Yttri
um (p
pm)
-100
100
300
500
700
900
1100
1300
0 40000 80000 120000 160000
type II
type I
type III
type IVtype V
Scattered content in yttrium : macroscopic zoning
Comparison with published data on garnets: Quast & Schlüsser 2000 (SEM-EDX)
Results
The garnets set on the Merowingian jewels were extracted from India and Sri Lanka
Evidence of two sources indian deposits
Coming from the East during the great Invasions, the first Frankish kings have kept their sources oriental ofgarnets
On the latest jewels (7th century), the type of garnetschanges: pyropes from Bohemia
Surprisingly from the 5th to the 7th century AD, the Barbarians have established a gem route to Asia.
study of provenance of gold used in Merowingian jewellery
The key feature for improving the limit of detection is the Peak/Background ratio of X-ray detectors
The interesting trace element are the Platinum Group elements (Ru, Rh, Pd, Os, Ir, Pt and Sn Sb . Typical content is 100 µg/g. The related lines lie in the 20 keV-range. Pt has its lines just underneath the Au lines at 9.44 keV
PIXE spectrum on the brooch
The interesting trace element : Platinum Group elements : (Ru, Rh, Pd, Pt, Os, Ir) and Sn Sb .
Typical content is 100 µg/g
The related lines lie in the 20 keV-range. Pt has its lines just underneath the Au lines at 9.44 keV
Improve manufacturing technology (reduce charge collection loss)
reduce shaping time / use digital pulse processor in order to reduce sum peaks
Hi-res spectrometry for chemical speciation
Chemical state (valence) accessible by means of X-ray satellite peaks resulting of bombardment withheavy particle (multiple shell ionization).
WDS ?
µ-Calorimeter ?
development of a portable XRF system for on the field analysis(museum, archaeological site…)
Peltier-cooled Si-drift diode300-µm crystal thickness: efficiency drops above 10 keVageing problemspoor peak/background ratio
Conclusion
The photon probe, due its non-destructive character, is recognised as a valuable tool for study of art and acheological artifacts
The study of cultural heritage will benefit from developments in photodetectors
Encouraging prospects
Good old Mona Lisa…
investigated using a state of the art detector…
…and with a new generation photodetector