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  • ESS/SAC/Report/1/01

    ESS – SAC/ENSA Workshop

    on

    “Scientific Trends in Condensed Matter Research and Instrumentation Opportunities at ESS”

    edited by

    D. Richter (Chairman of SAC)

    jointly organized by

    the Scientific Advisory Committee (SAC) of the European Spallation Source (ESS) and the European Neutron Scattering Association (ENSA)

    sponsored by

    European Science Foundation Swiss National Science Foundation European Neutron Round Table Paul Scherrer Institute Villigen Forschungszentrum Jülich

    Address: Institut für Festkörperforschung (IFF) Forschungszentrum Jülich D-52425 Jülich Germany

    Tel.: +49-(0)2461-61-2499 Fax: +49-(0)2461-61-2610 IFF Homepage: http://www.kfa-juelich.de/iff/Institute/ins/ins-d.shtml ESS Homepage: http://www.ess-europe.de

  • ESS – SAC/ENSA Workshop

    “Scientific Trends in Condensed Matter Research and Instrumentation Opportunities at ESS”

    Engelberg/Switzerland, 03. – 05.05.2001

    Contents

    Preface (D. Richter, SAC Chairman) I

    Preface (R. Cywinski, ENSA Chairman) II

    Executive Summary IV

    1. Introduction 1

    2. Science and Instrument Groups 3

    3. The ESS - SAC/ENSA Workshop on “Scientific Trends in Condensed Matter Research and Instrumentation Opportunities at ESS”

    4

    4. The Long Pulse Target Station 8

    5. Recommendations of the Scientific Advisory Committee 10

    6. Instrumentation issues, established techniques, need for innovation, technical risks (F. Mezei, HMI Berlin)

    13

    7. Science Group Reports

    7.1 Solid State Physics 34

    7.2 Material Science and Engineering 45

    7.3 Biology and Biotechnology 56

    7.4 Soft Condensed Matter 69

    7.5 Chemical Structure, Kinetics and Dynamics 80

    7.6 Earth Science, Environmental Science and Cultural Heritage 91

    7.7 Liquids and Glasses 107

    7.8 Fundamental Physics 119

    8. Appendix

    A1 Members of the Science Groups 126

    A2 Members of the Instrument Groups 127

    A3 Participants at the SAC/ENSA Workshop in Engelberg 128

    9. Acknowledgments 130

  • I

    Preface

    This document reports on a decisive step towards the final definition of the European

    Spallation Source (ESS). At the beginning of May 2001 in Engelberg (Switzerland), about 70

    scientists from all fields of neutron science encompassing solid state physics, material

    science and engineering, biology and biotechnology, soft condensed matter science,

    chemistry, earth and related sciences, the science of liquids and glasses and the physics of

    the neutron itself gathered in order to deliberate upon the optimum choice for the neutron

    parameters of ESS. The course of consideration went through a two stage process. Initially,

    the scientists identified high profile research areas in their scientific fields at the limit or

    beyond of what may be accessed today. From these so called flagship areas scientific

    demands on the performance of ESS were derived. Then, these demands were discussed in

    the frame of the instrumental opportunities offered by different configurations of ESS. This

    part of the discussions was guided by instrument specialists representing the different fields

    of instrumentation. From the synthesis of science considerations and instrumental

    opportunities a recommendation for the neutron parameters of ESS was reached.

    The report documents the scientific and instrumentation background which led to the

    recommendations for the choice of target stations and power levels at the ESS accelerator

    complex. The document emphasises strongly the science case considerations and in

    particular the high profile flagship areas which are behind the conclusions on the neutron

    parameters. With respect to the science case of ESS, this document is an important but

    intermediate step which will need to be completed adding information on the breath and the

    width of neutron research on science in general. Furthermore, the opportunities offered by

    innovative and novel instrumentation that will become possible at ESS, need to be outlayed

    in more detail. This next and final step will be completed within the next year. The resulting

    report will underpin the ESS project proposal and is aimed to be published together with

    European Science Foundation.

    I like to take the opportunity to thank all participating scientists for their extraordinary

    engagement and enthusiasm that became evident during the three intense working days in

    Engelberg. I also like to thank the conveners of the science groups for their efforts to

    complete the science group reports within a very short time after the workshop, allowing us

    to go into print less than one month after the event.

    Prof. D. Richter (Chairman of SAC)

    Jülich, 05.06.2001

  • II

    A Preface from the Chairman of ENSA

    Neutron scattering is a uniquely sensitive and extensively used experimental technique for studying the structure and dynamics of matter. However it is a technique that is strictly limited by the intensity of available neutron sources. Indeed since the pioneering neutron scattering studies of the Nobel Prize winners Shull and Brockhouse in the early 1950’s this source intensity has increased only by a factor of 4, an increase achieved almost 30 years ago with the commissioning of the world’s premiere neutron research reactor, the Institut Laue Langevin in Grenoble.

    Over the intervening decades the scientific and technological problems associated with the fine analysis of matter that depend crucially upon neutron scattering for their solution have grown enormously in complexity, subtlety and range. As a response to this burgeoning demand for ever more sensitive neutron scattering methods the European Spallation Source (ESS) Project was established in the early 1990s as the most direct and feasible approach to providing a new third generation neutron source. It is intended that the ESS will offer an effective increase in performance of between 10 and 100 over all existing neutron sources, depending upon the specific application. This achievement will represent by far the greatest single stepwise increase in source performance since the early 1950’s. The implications for neuron scattering science will be profound.

    By 1997 the scientific case for, and the technical design of, the ESS was published [1]. Indeed the ESS design had reached such an advanced state that the United States adopted the principal design features of the ESS as the basis for their own Spallation Neutron Source (SNS) project. The construction of the SNS commenced in 1999, but unfortunately there has been no parallel commitment to progress the ESS within Europe.

    The overriding need for a third generation neutron source in Europe has been emphasised within the global neutron strategy compiled by the OECD Megascience Forum [2] in 1998 and endorsed by the OECD Ministerial Conference in 1999. The OECD recommended that an advanced European neutron source should stand alongside complementary third generation neutron sources in America and Asia. Both the US and Japan have adopted these recommendations and are now, in 2001, well advanced with the design and construction of their own advanced regional sources (the SNS and JSNS respectively).

    It is the goal of the ESS project to provide the scientific case for and design of a neutron spallation source which will satisfy the OECD global neutron strategy and provide Europe with a top ranking neutron facility which will remain at the forefront of neutron scattering technology for at least the first half of the 21st century.

    Neutron scattering, although a uniquely sensitive probe of condensed matter, is strictly limited by neutron source intensity

    The ESS represents more than an order of magnitude improvement in source performance, an achievement unequalled in since the 1950s

    The OECD has endorsed a global neutron strategy which places a third generation neutron source in Europe, America and Asia. The US and Japan have already commnced construction

    The ESS will be the world leading neutron facility for the first half of the 21st

    century

  • III

    The ESS project has been strongly and vociferously supported by the European neutron scattering community, through its representive body, the European Neutron Scattering Association, ENSA. ENSA represents, via the elected delegates from 17 European national user communities, approximately 4500 physicists, chemists, material scientists and members of the life, earth and engineering science communities, all of whom view neutron scattering as an essential tool in their exploration and exploitation of the structure and dynamics of condensed matter.

    Although a close and effective collaboration between ENSA and the ESS Project has been in place for some time, the ESS Science Advisory Committee/ENSA workshop held in Engelberg between 3 and 5 May 2001 proved remarkably successful not only in defining an exciting and far reaching scientific case for the ESS, but also in building upon this scientific case in order to establish the optimal neutronic performance parameters for the ESS target stations necessary to enable the ESS to address the ambitious scientific challenges outlined in the scientific case.

    This report, prepared through an active collaboration between the ESS and ENSA presents a detailed discussion of the refined scientific case and its implications for the ESS target