EIPAM Final Report
EIPAM was a five year ESF programme that explored how low energy electrons may be used to both manipulate molecules and initiate chemistry in complex molecular systems including within clusters and on surfaces. The programme brought together both experimentalists and theorists from a wide range of disciplines including physics, chemistry, engineering and biology to both develop fundamental research and increasingly in its latter stages to develop the applications of such research to such diverse fields as Astrochemistry, radiation chemistry and the development of nanoscale lithography. The programme established a series of international collaborative projects involving researchers from 15 European Countries and developed strong links with US, Australian, Japanese and Indian. More than 200 publications may be linked to EIPAM support either in personal exchanges or through establishing links at EIPAM Meetings. Indeed the Programme supported 94 staff exchanges including several longer term (up to six months) research fellowships which have been welcomed by the (mostly younger) researchers engaged as being excellent mechanisms for their career development and fostering longer term career opportunities (18 leading in part to the visitor subsequently holding a research positions in the host institution)
The Programme has also acted as the catalyst for several further applications for transnational funding; A COST Action on Electron Chemical Controlled lithography was awarded (CM0601) and was launched in 2007 and an EU Research Infrastructure bids involving members of the EIPAM community was successful to develop a Virtual Atomic and Molecular Data Centre (VAMDC) which will include the data collated as part of EIPAM research (3 millions Euros 2009-2012). A major bid for an EU Framework VII Initial Training Network based on electron controlled chemistry leading to lithography was submitted in December 2009.
The EIPAM programme has been a (the) major catalyst for its research community to develop its research agenda on a transnational basis. In September 2006 the Programme was responsible for initiating a European-Australia research co-operation that was awarded a major grant from the Australian government for a collaborative research in electron and positron physics (an award recently reviewed, deemed ‘excellent’, and extended to 2012). EIPAM was also the impetus for several applications under the Framework VII Programme. Three Marie Curie senior incoming research professors (I Fabrikant, University of Nebraska USA: L Sanche University of Sherbrooke, Canada and E Krishnakumar, Tata Institute Mumbai, India) were successfully applied for and awarded partly on the basis of EIPAM and thence their ability to interact with a vibrant and EU research community in electron induced chemistry.
As the above indicates the EIPAM programme increasingly sought to develop links with more applied communities and in 2007 a meeting was held with researchers from Japanese plasma processing community to explore how basic research in electron control may be used to assist the development of nanoscale device fabrication using plasma technology. This has led to a series of independently funded annual workshops between EU and Japan on plasma processing and technology and both EU and international funding consortia applications to develop a collaborative science programme have been prepared and are under evaluation.
The role of electron chemistry in Astrochemistry and the formation of molecules in the Interstellar medium and in planetary atmospheres has been one highlight of the EIPAM programme opening a new and vibrant area of transdisciplinary research. A COST Action based on Astrochemistry (CM0805) was awarded and launched in 2009 and includes a working group that is dedicated to understanding the role of electron induced chemistry and a European Research Infrastructure on planetary science (Europlanet) linking more than 30 research groups to share facilities and develop joint research with a budget of 6 million Euros was awarded in 2009 for four years. These are supported by an Initial Training Network (ITN) based on Astrochemistry including EIPAM related research which was awarded late in 2009 (LASSIE ) with another 6 million Euros.
The third research area of the EIPAM and one that has perhaps received the widest publicity was related to gaining an understanding of low energy electrons interacting with biomolecules and the role of electron induced damage in DNA. Such research (initiated in 2000 by a seminal paper by Sanche and co-workers in Sherbrooke Canada) has led to a fundamental reappraisal of the mechanism of radiation damage at the DNA level. The EIPAM and the EU community have led the international research programme in this area since 2003/4 and now using such fundamental knowledge acquired during EIPAM to explore new possible therapies for Cancer treatment. A Cost action on radiotherapy is therefore currently; under evaluation having reached final stage of selection process for 2010 and a major bid for EU funds to support research on radiation damage induced by low doses over long term exposures will be submitted in April 2010 as part of the Euratom programme.
‘Finally’ the EIPAM programme has also engaged with researchers engaged in fusion research and in the development of next generation lighting sources to discuss how a better understanding of electron induced processes may be exploited in these fields.
Therefore in summary we believe EIPAM has been an extremely successful research programme building a strong and vibrant interdisciplinary research community that has secured further funding to develop its research along a number of different research paths but l based on a core knowledge of the role of electrons in induced physical and chemical change in their local environment. We therefore thank the ESF for their support and the opportunity that this Research Network allowed.
2. Programme Objectives
The ability to understand, manipulate and control chemical reactions at the molecular level remains one of the great challenges of modern research. Since chemical processes are dominant in most areas of science and technology the ability to control their pathways will provide exciting new opportunities that may be exploited by both the research and technological communities. Such ‘single molecule engineering’ requires selective bond cleavage in target molecules to allow subsequent management of the local site chemistry. Since electrons are ubiquitous in nature and electron induced reactions (in the gaseous phase, on surfaces and in the condensed phase) initiate and drive the basic physical-chemical processes in many areas of science and technology from industrial plasmas to living tissues our ability to control electron interactions provides exciting new opportunities that can now be exploited by both the research and technological communities. For example, the development of the Scanning Tunnel Microscope (STM) -an electron emitter- has introduced the capability of atomic-scale imaging, analysis and individual atomic/molecular manipulation providing a new technology that has the opportunity to revolutionize the scientific approach in many aspects of both the material and life sciences.
Europe remains at the forefront of such pioneering research but, in contrast to the USA and Japan, the European research effort prior to the EIPAM Research Network had been somewhat fragmented and international coordination was rudimentary. The ESF supported EIPAM programme was aimed at bringing together Europe's leading experimental and theoretical groups in a large-scale, multidisciplinary and collaborative research programme that would establish Europe as the centre for investigations of molecular control through electron processing with direct relevance in many areas from the basic sciences to industrial applications.
EIPAM based research was focused on four strongly inter-linked scientific strands:
The programme aimed to both develop basic research in these four strands and to then seek to determine how such knowledge was relevant to applied research areas. The programme would meet its aims by hosting research conferences where leading members of the EU research community could meet to present and discuss their research and through the support of an extensive programme of scientific exchanges, both short term (1 to 4 weeks) and longer term (1 to 6 months), to conduct joint research projects. These exchanges were mainly aimed at younger career researchers (Postgraduate and Postdoctoral).
3. Results achieved
During the course of the Research Network major progress was made in all these areas of research. Space limitations do not allow a comprehensive review of all the research that has been enabled under EIPAM so only a few highlights will be presented here.
Strand 1. Some of the most dramatic progress in the Programme has been in the study of electron scattering from bio-molecules in particular the DNA bases adenine, cytosine, guanine, thymine and RNA base uracil and, most recently, the larger biomolecules including glycine, simple sugars and amino/fatty acids. EIPAM partners (e.g. University of Innsbruck, The Open University Free University of Berlin) demonstrated that the low energy electron process of ‘Dissociative Electron Attachment’ (DEA) is a dominant process when low energy electrons (< 10eV) interact with biomolecular systems. DEA is a resonant process occurring with a strong cross section over a narrow energy region (1-2eV) and occurs trough the capture of the incident electron by the target molecule with the subsequent ‘anion’ often decaying by fragmentation producing a product anion and one or more neutral (often reactive) fragments. EIPAM supported projects revealed that DEA is both bond (C-H versus N-H) and site selective (N1-H versus N3-H and C6-H versus CH3) in the DNA bases. These pioneering results (reported in several PRL publications) suggest that it may be possible to explain DNA damage at a basic molecular level with low energy secondary electrons produced by primary radiation (eg Xrays, protons or heavy ions used in cancer therapy) producing the DNA damage that consequently leads to destruction of the cancerous cell. Indeed recent work by Berlin, Innsbruck and Open University groups has demonstrated a correlation between electron attachment rates to biomolecules and their carcinogenicity and this is now being used to suggest new compounds to be adopted in radiation therapy as treatment enhancing sensitizers, e.g. 5-bromouracil or the use of gold nanoparticles, (themselves a source of low energy secondary electrons during irradiation) as a cancer therapy agent. Since the majority of the research was initially conducted using gas phase biomolecular targets the direct application of such data in modelling cellular processes remains controversial. Therefore in the latter stages of the EIPAM programme research was developed to study biomolecules embedded in clusters as these may be more representative of cellular conditions. Clearly the most important molecular with which biomolecules interact is water. The EIPAM programme therefore supported and extensive study of electron interactions with water including detailed gas phase dissociative electron attachment experiments to water (University of Innsbruck and Open University) electron interactions in water ice (Aarhus Denmark), positron-water interactions (relevant to PET studies). These experiments were complemented by detailed theoretical calculations (eg University College London, Charles University and Hevrovsky Institute Prague and Sapienza University, Rome) see below (strand 4).
Strand 2. The second highlight of EIPAM Research was the experimental demonstration that slow electrons can act as a soft tool to control chemical reactions in the condensed phase. By setting the energy of a well defined electron beam to values below 3 eV it has been shown that it is possible to initiate chemistry at very low incident energies - energies less than that predicted to rupture chemical bonds. This low energy chemistry is once again driven by the process of dissociative electron attachment (DEA). DEA fragments may then initiate further chemical reactions. For example in a CH3Cl/NF3 cluster F- from NF3 reacts with CH3Cl by F- + CH3Cl CH3F + Cl-. An identical process may occur on a multilayer of co-deposited CH3Cl and NF3.Cl- desorbs from the film leaving CH3F so a multilayer may be chemically converted into pure film of another chemical species. Chemical reactivity has also been induced following electron irradiations of mixture of ammonia and acetic acid at 25K. Amongst the irradiation products is the amino acid, glycine. Such results have important consequences for Astrochemistry where the observation of increasingly complex molecular species in the interstellar medium (including now glycine!) opens the debate as to the mechanisms by which these can be formed since the low temperatures (10K) and low densities would preclude traditional gas phase chemistry. Hence the possibility/probability of electron induced heterogeneous chemistry within the dust mantle of ice covered dust grains in the ISM has great appeal and is now the topic of major research programme both laboratory studies, modelling and, with the launch of Herschel Space telescope and the commissioning of the ALMA telescope, in coming decade OBSERVATIONS.
Electron-induced reactions can also bind specific functional groups to a surface in a controlled way. DEA of acetonitrile CH3CN + e- CH2CN- + H being used in the functionalization of hydrogenated diamond to attach organic groups to surfaces. Such experiments suggest that it is possible to manipulate molecular reactions on surfaces using low energy electrons. This research has great significance in the nanotechnology area where ‘nanoscale lithography’ may be induced by electron patterning (perhaps using scanning tunnel microscopes). Such DEA induced processing has been entitled Electron induced chemical lithography and is the topic of a European Science Foundation COST Action which was ranked as the leading chemistry proposal in 2007. Under the auspices of this Action and EIPAM the fundamental research community has engaged with the industrial lithography community (eg Carl Zeiss, Raith inc) to develop a research programme for developing low energy electron lithography to fashion nanoscale structures.
Strand 3. In seeking to develop nanoscale tools fro surface processing the EIPAM programme sought to incorporate members of the EU’s Scanning Tunnel Microscopy community to develop the STM as a chemical tool. STMs are in fact an electron source, a source of high brightness and potentially high resolution. Therefore they have the potential to become a tool for preparing novel nanoscale structures fashioned using electron induced processing. For many years STMs have lacked chemical specificity, requiring complementary spectroscopic tools to identify the chemical species being imaged however, recently STM–IETS (STM Inelastic Electron Tunnelling Spectroscopy) has been developed to measure the vibrational spectrum of a single molecule, allowing STMs to be used as a tool for chemical analysis of single molecules. EIPAM members at the University of Toulouse, University of Liverpool and Free University of Berlin have been at the forefront of this research.(e.g. N Lorente, J J Pascual and H Ueda Surface Science 593 122-132 (2005) whilst the University of Birmingham demonstated for the first time that STMs may be used to induce DEA in a single molecule. Furthermore that since the STM is such a bight electron source two electron interactions may be induced in a single molecule, the first preparing the target in a specific excited state the second inducing fragmentation (e.g. through DEA). By such electron processes chemical pathways can be controlled and new molecular structures fashioned. One of the electrons may be replaced with a photon(s) as demonstrated by EIPAM member (University of Hannover). Thus STM induced chemistry is now a field that is developing rapidly but before it can be developed commercially there is a need to develop methods for scaling up from single tips and there is a need to develop STM theory that includes chemical reactivity. Several EIPAM members are engaged in this and the work is developing as a core part of the new COST CM0601 Action.
Strand 4. Methodology and general purpose codes, built upon existing codes constructed by teams in the network, have been developed to study fundamental electron interactions with increasingly complex molecules leading to excitation and dissociation. Recently Researchers at University College London and Open University have developed their computational codes to study larger molecular systems with first results on tetrahydrofuran, formic acid dimmer and water clusters being presented at EIPAM meetings. The UCL group has also reported the first results for electron induced dissociation of the water molecule. The Research group in Sapienza University Rome have performed the first electron scattering calculations on complex biological molecules (e.g. glycine and the DNA bases). Researchers in Prague have developed a computational scheme based on the Discrete Momentum Representation to derive energy loss spectra and a model, based on the quantum defect theory approach to electron-polar molecule collisions, to derive the first set of data for state-to-state rotationally inelastic scattering cross-sections. This research has been greatly advanced by the provision of longer fellowships supported by the EIPAM programme. In addition the programme has helped to reinvigorate an EU programme of positron based research with one EIPAM Fellow (K Franz) developing UK based R matrix code for positron-molecule scattering. This in turn assisted in the recent EU Australia collaborative award on electron/positron chemistry with the newly established Centre for Antimatter Matter Studies. These calculations are being more widely incorporated into track models used to quantify radiation damage in cellular systems and used in the clinic to set dose treatment. CIEMAT, Madrid, Spain a core EIPAM partner has shown that current dose models poorly represent electron molecular interactions and that using semi empirical representations developed under EIPAM a more realistic representation of track structure can be develop leading to consequences for dose planning in the clinic. This research is now subject of new EU projects currently under review (as a COST Action) and in preparation for an EU Framework project.
As part of the EIPAM programme we established an annual series of meetings. The first was held in Viterbo. Italy 25-30 June 2005, the Second in Valletta Malta 16-20 September 2006 the third in Iceland 25-29 May 2007, the fourth in Roscoff, France, 7 - 11 May 2008 and, although after the end of the project and not supported by ESF finances a fifth held jointly with the Australian community in Trieste 12-16 October 2009 (see below). These meetings have provided a unique forum for interdisciplinary discussions between STM surface science and atomic and molecular communities. At the EIPAM06 meeting we signed a Memorandum of Understanding with colleagues in Australia which formed part of an application to the Australian Government for a collaborative programme in Electron and Positron induced chemistry. This was awarded in November 2006 and began 2007 initially for a three year period supporting staff exchanges and an annual meeting, that is 200 being held under EIPA title in Trieste. In March 2007 in Belgrade we held a collaborative meeting with Japanese Colleagues as part of the EU-Japan Plasma Processing Conference series to explore how basic research in electron control may be used to assist the development of nanoscale device fabrication using plasma technology. EIPAM also supported the Low Energy Electron Molecule Interactions (LEEMI) meeting in Smolenice, Slovakia 6-10 October, 2005 and LEEMI merged with EIPAM for the meeting in Roscoff in 2008.. Day schools in STM were arranged in Berlin and Birmingham in 2005. A special meeting/school was arranged for young theoreticians in Prague February 14-18 2005 to discuss future directions in electron molecule theory. Several members of the EIPAM community also participated in the ESF sponsored meeting Biomolecules from Gas Phase Properties to the Actions Relevant to Living Cells Obergurgl, Austria, 27th June – 1st July, 2006 and in 2008 ESF supported a Conference on Chemical Control with Electrons and Protons also at Obergurgl Austria 22-27 November). Since 200 members of the EIPAM community have continued to meet as part of the COST Action CM0601 on Electron Controlled Chemical Lithography (inaugural meeting Lisbon 12-16 march 2008 , second meeting Istanbul 4-9 June 2009). Members of EIPAM have also been invited to attend the annual Radiation Damage meeting (RADAM) organised annually in Europe since 2004.
The Steering Committee determined that a major proportion of the budget should be used for staff exchanges and establishing short term fellowships to allow research teams in Europe to develop collaborations and formulate joint research programmes. These have been very successful and very popular. We have particularly geared many of these visits at younger scientists. allowing them access to facilities that they do not have in their own Universities. Such visits have been (and are) extremely useful parts of their PhD programmes or Postdoctoral Research. Senior staff also exploited the opportunities for short visits to develop collaborations In total 94 such exchanges were arranged and we believe these to be the most effective parts of the Network leading to longer scale co-operations with 18 leading in part to the visitor subsequently holding a research positions in the host institution.
4. European Added Value and Visibility of the Programme
Whilst not wishing to overplay the role of the ESF Programme in the wider EU/International research programme we strongly believe that the opportunities provided by the Programme have provided an essential part of the emergence of the EU community as the world leader in electron driven research. Although there are, of course, centres of research excellence in the USA, Canada and Australia it is now the European research community that is leading much of the international research agenda, particularly in study of electron interactions with biomolecules, the role of electron processes in astrochemistry and the development of electron induced chemistry/lithography. This was the primary aim of the ESF Programme and we believe that the ability to develop joint research projects, exchange staff and hold regular well funded meetings has greatly aided this process. The invitation to work with the Japanese Plasma research/industry in developing joint research, the funding of the Joint EU Australia programme in Electron and Positron research (by the Australian Government) and the award of major EU Framework funding in astrochemistry and planetary science are, we believe testament to this leadership.
5. Programme Finances and Management
The financial expenditure is reported in the Appendices. As stated above we sought to provide a significant part of the budget towards visits and Fellowships whilst hosting one major meeting each year, and where appropriate supporting smaller strategic workshops. The growing number of publications recognising EIPAM as a source of support we feel justified this and represented extremely good value for money (<5000 Euros per paper !).
The Management Structure operated without difficulty, the Steering Commitee meeting once a were changes in Membership of the Steering Committee (the addition of Prof O Ingolfson for Iceland, the departure of Prof M Persson from Sweden to Liverpool, UK (to be replaced by Prof M Larsson, Stockholm) replacement of P Scheier for T Maerk (Austria) P Limao-Vieira for Portugal, Prof G Garcia for Spain). We also welcomed (non voting) representatives for France (A Lafosse/G Dujardin) and Italy (F Gianturco) even though their countries had not signed the programme since it we believe it was important to have the research of these countries represented in the Science plan. Finally we would like to note the excellent support provided by Ms B Harker at Open University who acted as EIPAM Secretary; Dr N C Jones Aarhus Denmark who acted as Webmaster and Chantal Durant at the ESF whose efficiency and help in ensuring the smooth operation of the programme was greatly appreciated.
The programme had its own website (http://www.isa.au.dk/networks/eipam) which proved to be very successful in attracting new groups interest in the programme and developing applications for visits/fellowships. We are also negociating a book of review papers with a commercial publisher with the intention of publication in late 2010. We would also note that several participants have had their work featured in their national media (e.g. Teams in Free University Berlin, University of Innsbruck, University of Aarhus).
7. Forward Perspectives
As discussed above we believe that EIPAM was an major success that clearly met is aims and objectives of developing a strong and vibrant interdisciplinary research community across Europe, one that has secured both momentum and funding to develop in the next few years. These include;
We also wish to build upon links formed in the latter stages of the EIPAM programme to (i) link electron and positron studies and (ii) form closer interactions with plasma research community and study of ion interactions and ion-molecule chemistry, for example to study electron ion recombination which is so important in astrochemistry and in technological plasmas. Positron interactions with matter have both applied applications (e.g. their use in medical therapy and as a tool for surface analysis) and provide exciting new insights into the interaction of simple leptons with molecules (the processes of annihilation and positronium formation being introduced in positron interactions). The EIPAM programme links with the large scale Centre for Antimatter-Matter Studies (http://www.positron.edu.au/index.html) established in Canberra Australia will therefore be continued and developed (Australian support having recently been extended to 2012).
Electron induced processes drive most of the fundamental physical and chemical processes in technological plasmas (e.g. those used in lighting, semiconductor chip manufacture, ozone production for sterilisation etc). The development of the next generation of plasma sources requires a more detailed knowledge of the electron interactions for example Japanese industry is exploring the development of electronegative plasmas as a tool for nanoscale technology (e.g. seminal paper ‘Ultimate top-down etching processes for future nanoscale devices: Advanced neutral-beam etching’ S JAPANESE JOURNAL OF APPLIED PHYSICS 45 2395-2407 (2006), hence the development of EIPAM studies in collaboration with the plasma community needs to be further developed.
The two fields in which EIPAM now has direct continuation support are:
Electron controlled chemical lithography (ECCL) is supported through the COST Action CM0601 (http://www.isa.au.dk/networks/eccl/index.html) which supports annual; meeting and short visits and has developed strong links with industry allowing it to submit an Initial Training Network to the EU Framework VII Marie Curie Programme. The Action is Chaired by Professor O Ingolfsson, Iceland who joined the EU community through the EIPAM programme and has since emerged as a leader of the community. He states that without EIPAM his research career would have followed very different (and much more isolated) path.
Astrochemistry research has developed rapidly in the last 2-3 years with the role of electrons induced chemistry becoming one of the hot topics of the field. Also supported by another COST Action (CM0805) chaired by N J mason (Chair of EIPAM) and awarded support from the EU Framework programme, this will be one of the most active areas of research in the next 4 years. EIPAM members are engaging with astronomers, planetary scientists and even space missions technicians in a manner unthought of at the commencement of EIPAM. EIPAM built and supported thee links ion their earliest stages and this is perhaps a fitting final tribute to the EIPAM programme and the opportunities the ESF Research Network scheme provides.
Professor N J Mason on behalf of the EIPAM Steering Committee