PHYSICAL TECHNIQUES IN THE STUDY OF ART, ARCHAEOLOGY AND CULTURAL HERITAGE VOLUME 2 Cover illustration: The images printed on the cover are taken from the chapter by Maria Kubik (Chapter 5) and show a plain photograph and two hyperspectral images of a painting in the collection of the Australian War Memorial. Left: Photograph of the original painting. Centre and Right: Hyperspectral images of the painting, showing the location of pigments of different types used by the artist. [The image of the painting of an Australian soldier by Ivor Hele was taken with the permission of the Australian War Memorial. The photograph of the original painting was taken by the author in the course of her investigations, and is not an official reproduction of the painting (ART40317) in the Australian War Memorial catalogue.] PHYSICAL TECHNIQUES IN THE STUDY OF ART, ARCHAEOLOGY AND CULTURAL HERITAGE Editors DUDLEY CREAGH University of Canberra Faculty of Information Sciences and Engineering Canberra, ACT 2600, Australia DAVID BRADLEY University of Surrey Department of Physics, Guildford GU2 7XH, UK VOLUME 2 Amsterdam • Boston • Heidelberg • London • New York • Oxford Paris • San Diego • San Francisco • Singapore • Sydney • Tokyo ELSEVIER Radarweg 29, PO Box 211, 1000 AE Amsterdam, The Netherlands Linacre House, Jordan Hill, Oxford OX2 8DP, UK First edition: 2007 Copyright ©2007 Elsevier B.V. All rights reserved No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the publisher Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone (+44) (0) 1865 843830; fax (+44) (0) 1865 853333; Email: [email protected]. Alternatively you can submit your request online by visiting the Elsevier web site at http://elsevier.com/locate/permissions, and selecting: Obtaining permission to use Elsevier material Notice No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made ISBN-13: 978-0-444-52856-8 ISSN: 1871-1731 For information on all Elsevier publications visit our website at books.elsevier.com Printed and bound in The Netherlands 07 08 09 10 11 10 9 8 7 6 5 4 3 2 1 Contents Preface vii Chapter 1 Synchrotron Radiation and its Use in Art, Archaeometry, and Cultural Heritage Studies 1 Dudley Creagh 1. Introduction 2 2. The principles of synchrotron radiation generation 4 3. Synchrotron radiation beamlines 24 4. Detectors 37 5. Techniques 43 Acknowledgements 90 References 91 Chapter 2 Synchrotron Imaging for Archaeology, Art History, Conservation, and Palaeontology 97 L. Bertrand 1. Introduction 98 2. Current use of synchrotron imaging on ancient materials 99 3. Experimental requirements 102 4. Examples of imaging experiments 104 5. Conclusions: some way forward 109 Acknowledgements 111 References 112 Chapter 3 Holistic Modeling of Gas and Aerosol Deposition and the Degradation of Cultural Objects 115 I.S. Cole, D.A. Paterson and D. Lau 1. Introduction 116 2. Types and sizes of particles and types of gases 118 3. Deposition mechanisms 121 4. Deposition equations 125 v vi Contents 5. Generation, transport and deposition on cultural objects exposed to the external environment 133 6. Generation, transport and deposition on cultural objects inside buildings 137 7. Surface forms and degradation 148 8. Implications for design and maintenance strategies 151 9. Conclusions 152 References 152 Chapter 4 Examples of Using Advanced Analytical Techniques to Investigate the Degradation of Photographic Materials 155 Giovanna Di Pietro 1. Introduction 156 2. Silver mirroring on silver gelatin glass plates 158 3. Identification of photographic dyes in colour motion picture films 178 References 196 Chapter 5 Hyperspectral Imaging: A New Technique for the Non-Invasive Study of Artworks 199 Maria Kubik 1. Introduction 200 2. The principles of reflectance and hyperspectral imaging 201 3. Building a hyperspectral imaging system 209 4. Selected applications 227 Acknowledgements 255 References 255 Author Index 261 Subject Index 271 Preface In this Volume 2 of the series on the use of physical techniques for the study of art, archae- ology, and cultural heritage, we continue our policy of choosing topics from widely differ- ent fields of cultural heritage conservation. Also, we have chosen authors both in their early and late careers. In Chapter 1, Dudley Creagh writes on “Synchrotron radiation and its use in art, archaeometry, and cultural heritage studies”. He is Professor and a Director of the Cultural Heritage Research Centre at the University of Canberra, Canberra, Australia. He has exten- sive experience in all aspects of cultural heritage research. Inter alia, he was a member of the team responsible for the restoration of the Japanese Zero fighter at the Australian War Memorial, conducted research on prestigious medals such as the Victoria Cross and the Lusitania Medal, investigated the effect of self-organizing alkyl chain molecules for the protection of outdoor bronze sculptures, and studied the properties of lubricating oils necessary for the proper preservation of working vintage motor vehicles. Research groups led by him have studied the mechanisms underlying the degradation of Australian aborig- inal bark paintings, and examined of the degradation of iron-gall inks on parchment, dyes and pigments in motion picture film, and dyes and pigments on painted surfaces. Prof. Creagh has also designed new equipment and devised new techniques of analysis. He designed the Australian National Beamline at the Photon Factory, KEK, Tsukuba, Japan. With Dr. Stephen Wilkins, he also designed the unique X-ray diffractometer (BIGDIFF) mounted on it. He designed a number of its accessories, including an eight- position specimen-spinning stage. For surface studies on air–liquidinterfaces, he designed an X-ray interferometer for the Research School of Chemistry at the Australian National University. He has designed X-ray interferometers that are now finding application in the phase contrast imaging of small objects. More recently, he has designed the infrared beam- line for the Australian Synchrotron, Melbourne, Australia. He is currently President of the International Radiation Physics Society. In continuation of the theme on synchrotron radiation, Loic Bertrand has elaborated, in Chapter 2, on synchrotron imaging for archaeology and art history, conservation, and palaeontology. Dr. Bertrand is the archaeology and cultural heritage officer at the new French synchrotron, Synchrotron Soleil (Orme les Mesuriers, Gif-sur-Yvette, France). He is charged with the task of raising the awareness of cultural heritage scientists to the use of synchrotron radiation for their research. With Dr. Manolis Pantos, he is responsible for the database that lists all the cultural heritage and archaeological publications involving the use of synchrotron radiation. He is an early-career researcher; but mentioning this undervalues vii viii Preface thecontribution he has already made to the field, using a variety of experimental techniques. In Chapter 2 he describes a number of his activities as well as the research of others. In the other chapters of this volume, widely different issues are addressed. Chapter 3 is authored by Ivan Cole and his associates Dr. David Paterson and Deborah Lau. This chap- ter is concerned with the holistic modelling of gas and aerosol deposition, and the degra- dation of cultural objects. Dr. Cole is the Deputy Chief of the Novel Materials and Processes Division of the Commonwealth Scientific and Industrial Research Organization (Melbourne, Australia). He has over 20 years experience of being involved in projects concerned with the preservation of cultural heritage. Ivan is an internationally recognized leader in the field of life cycle of materials and the development of protective coatings for metals. In 2004, he was a co-winner of the Guy Bengough Award (UK Institute of Materials, Minerals and Mining). He has taken lead roles in major projects in intelligent vehicle health monitoring for aerospace applications, the relation between building design and climate and component life, as well as the development of performance-based guid- ance standards and codes for durable buildings. He has made a significant contribution in the application of building and material science to the conservation of cultural buildings and collections. Ivan is a member of international and national committees for research and standards in durable structures. In Chapter 4, Giovanna Di Pietro describes two different types of experiments she has undertaken in the study of the mechanisms underlying the degradation of photographic media. In the first, she describes the degradation of old black-and-white plates. In the second, she outlines her attempts to understand the mechanisms by which the compara- tively modern motion picture film degrades. A significant part of this project involved trying to ascertain exactly which dyes were used by Kodak in their motion picture film from about 1980 onwards. The level of secrecy to which this information was protected was great. And, to this day, no information has officially been divulged by the company, although sufficient information has now been acquired to infer the formulations. Giovanna is a post doctoral researcher at the Institute for the Conservation of Monuments, Research Laboratory on Technology and Conservation Polytechnic University of Zurich, Switzerland. Her current project involves monitoring wall paintings using techniques derived from information technology. Giovanna’s other research interests include, inter alia, the effect of microclimate on canvas paintings. She is a consultant to museums and archives in the field of photographic preservation. An entirely new technique for the remote investigation of the pigments in paintings is presented by Maria Kubik in Chapter 5. This technique will significantly enhance the abil- ity of conservators to study the palette of pigments used by artists, check for repairs by others, and detect fraudulent paintings. It complements the techniques described by Prof. Franz Mairinger in an earlier Elsevier book Radiation in Art and Archaeometry, edited by Creagh and Bradley (2000). Maria is to receive her PhD from the Australian National University in April 2007. She studied conservation in the Cultural Heritage Conservation Course at the University of Canberra, graduating with the degree of Master of Science, specializing in painting conservation. She is at present the Conservator of Paintings at the Western Australia Gallery. Dudley Creagh David Bradley Chapter 1 Synchrotron Radiation and its Use in Art, Archaeometry, and Cultural Heritage Studies Dudley Creagh Director, Cultural Heritage Research, Division of Health Science and Design, University of Canberra, Canberra ACT 2601, Australia Email: [email protected] Abstract Synchrotron radiation has become an increasingly important tool for research in the fields of art, archaeometry, and the conservation of objects of cultural heritage significance. Scientists using conventional laboratory tech- niques are finding that the fundamental characteristics of synchrotron radiation – high brightness, low divergence, and highly linear polarization – can be used to give information not readily available in the laboratory context. In the author’s experience, experiments do not translate directly from the laboratory to the synchrotron radiation laboratory: there are subtle differences in the use of what seem to be similar experimental apparatus. To achieve the best results, the research scientist must be able to discuss his or her research aims meaningfully with beam- line scientists. And to be able to do this, the research scientist must have an understanding of the properties of synchrotron radiation, and also the various techniques that are available at synchrotrons but are unavailable in the laboratory. The chapter includes a discussion of synchrotron radiation and its properties, monochromators, detec- tors, and techniques such as infrared (IR) microscopy; soft X-ray spectroscopy; X-ray diffraction; micro-X-ray diffraction and X-ray fluorescence analysis; X-ray absorption spectroscopy (XAS), including extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES), and X-ray tomography. The underlying principles of these techniques are discussed here. Later in this book, authors will address these techniques in more detail. Keywords:Synchrotron radiation, IR microscopy, XRD, micro-XRD, micro-XRF, XAS, XAFS, XANES, X-ray tomography. Contents 1. Introduction 2 2. The principles of synchrotron radiation generation 4 2.1. Introduction 4 2.2. Synchrotron radiation sources 7 2.2.1. Bending-magnet sources 7 2.2.2. Second- and third-generation synchrotrons 14 3. Synchrotron radiation beamlines 24 3.1. General comments 24 3.1.1. Interfaces 30 3.1.2. Mirrors and capillaries 31 3.2. Monochromators 33 3.2.1. Crystal monochromators 33 3.2.2. Laboratory monochromator systems 34 Physical Techniques in the Study of Art, Archaeology and Cultural Heritage 1 Edited by D. Creagh and D. Bradley ©2007 Elsevier B.V. All rights reserved