Bei dem Vorhaben handelt es sich um ein Verbundvorhaben mit der GRS. Das Ziel des Verbundvorhabens mit der GRS ist die radiometrische Charakterisierung und Quantifizierung von C-14 in Reaktorgraphit mittels Beschleuniger-Massenspektrometrie. Das Verbundvorhaben gliedert sich in die Teilvorhaben 'Entwicklung eines Systems zur routinemäßigen Bestimmung von C-14 in Reaktorgraphit mittels Beschleuniger-Massenspektrometrie' (TV Universität zu Köln) und 'Optimierung der Entscheidungsmessung und Freigabemengen' (TV GRS). Ziel des hier beantragten Teilvorhabens ist die Entwicklung eines automatisierbaren Systems zur zuverlässigen Charakterisierung und Quantifizierung des C-14-Gehalts von Reaktorgraphit mittels Beschleuniger-Massenspektrometrie (Accelerator Mass Spectrometry, AMS), das im industriellen Bereich eingesetzt werden kann und Schwierigkeiten z.B. im Bereich der Untergrundunterdrückung oder aufwändiger Probenaufbereitung bei bisher genutzten Verfahren wie Liquid Scintillation Counting (LSC) umgeht und gleichzeitig in der Lage ist, das Unterschreiten der künftig geltenden Freigabewerte zuverlässig zu belegen . Ferner sollen Schnittstellen eines solchen AMS-Systems für die Messung weiterer Radionuklide definiert werden, um künftig die simultane Messung von C-14, Cl-36 und H-3 aus einer einzelnen Probe zu ermöglichen.
Recent progress in the operation of CO2 gas ion sources for accelerator mass spectrometer (AMS) 14C analysis on microgram-size samples opens a wide range of new applications in dating studies, e.g. for environmental and archeological applications. This proposal aims at implementing a gas ion source at the AMS system MICADAS at the Klaus-Tschira Laboratory of the Curt-Engelhorn-Zentrum für Archäometrie (CEZA) in Mannheim and to use this new capability for cutting-edge applications in environmental studies, namely the dating of small amounts of organic carbon contained in glacier ice and of specific organic compounds in ground water. Cold glaciers hold unique records on past climate and atmospheric composition. Mid-latitude ice cores furthermore enable reconstructions of recent ice chemistry changes, but cannot be dated by stratigraphic methods. For such ice bodies, only radiometric dating based on 14C analysis of organic matter contained in the ice matrix presently offers a reasonable dating potential in the late Holocene and beyond. The challenge of this approach lies in the very restricted availability of this matter, but the ability to analyse microgram samples of organic carbon from ice via a gas ion source should now enable reliable 14C dating of ice. Ground water constitutes an important water resource worldwide, especially in semi-arid regions, and in addition constitutes a useful climate archive. Dating of ground water by 14C in the dissolved inorganic carbon (DIC) is standard but problematic due to the complex carbonate geochemistry. Dating of ground water based on dissolved organic carbon (DOC) has been attempted with mixed success, but now the new analytical developments enable compound-specific 14C analyses of the various DOC components, offering the chance to identify compounds suitable for dating. This project is based on the extensive experience of the collaborating scientists in 14C analytics and applications as well as in the use of glacier ice and ground water as archives, including the development and application of 14C dating methods for these systems. It will establish 14C-measurements at the MICADAS AMS of the CEZA via a gas ion source on a routine base to analyse CO2-samples in the range of 5 to 40 microgram C at a precision down to 0,5 Prozent. By improving existing sample preparation techniques for glacier ice samples, reliable 14C values of the particulate and dissolved organic fractions from small (some 100 g) ice samples shall be obtained. This capability will be applied to constrain ages of cold, sedimentary glaciers as well as of small scale, cold Alpine congelation ice bodies. The project will further develop and test the tools required for micro-scale, compound-specific radiocarbon dating of ground water via its organic fraction. For this purpose, ground water samples from the Upper Rhine Graben area will be analysed, where extensive isotopic data, including DIC 14C values, are available for comparison.
Different concepts involving critical (fast) reactors or subcritical accelerator-driven systems are being studied in view of their transmutation capabilities. These design studies imply high demands on the underlying nuclear database. The need for improved nuclear data has been expressed in the Strategic Research Agenda of the SNE-TP ( Sustainable Nuclear Energy Technology Platform). The accurate knowledge of neutron and proton induced nuclear reactions in the fast, intermediate- and high energy domains (En=1keV to 500 MeV) is of crucial importance for predicting the capabilities of reducing the inventory of plutonium, minor actinides, and long-lived fission products. In the past, this energy domain was not investigated with high priority because of minor importance for conventional light-water reactors. An additional challenge is the tightening demand on the accuracy of the data, especially for assessing criticality safety aspects and designing fuels for very high burn-up. The ERINDA project aims for a coordination of European efforts to exploit up-to-date neutron beam technology for novel research on advanced concepts for nuclear fission reactors and the transmutation of radioactive waste. Such waste is already existing in appreciable quantity due to the year-Iong operation of existing nuclear reactors and it will eventually also be generated during the running of new reactor types - albeit they can be optimized to produce much less of it. Research to the aim of finding techniques optimized for a strong reduction of nuclear waste can already be performed at existing nuclear facilities from the consortium proposed in this proposal. The main objective is to provide adequate transnational access to the infrastructures. The consortium will also provide funding for scientific support of experiments by short term visits of scientist to the participating facilities and foster the communication and disseminaton of the results by organising scientific workshops.
The scientific objective of CLOUD is to investigate the influence of galactic cosmic rays (GCRs) on ions, aerosols, cloud condensation nuclei (CCN) and clouds, with the CLOUD facility at CERN, and thereby to assess the significance of a possible 'solar indirect' contribution to climate change. Aerosols and clouds are recognised as representing the largest uncertainty in the current understanding of climate change. The Intergovernmental Panel on Climate Change (IPCC) estimates that changes of solar irradiance ('direct solar forcing') have made only a small (7Prozent) contribution to the observed warming. However, large uncertainties remain on other solar-related contributions, such as the effects of changes of galactic cosmic rays on aerosols and clouds. CLOUD aims to settle the important unanswered questions of the IPCC on possible cosmic ray effects on clouds and climate, and to help sharpen our understanding of the anthropogenic contribution to global warming. We have established a central CLOUD facility in the beamline T11 at the CERN Proton Synchrotron accelerator, comprising a large aerosol chamber, within which the atmosphere is recreated from ultra-pure air with added water vapour, trace gases under study and, for certain experiments, aerosols. The chamber is equipped with a wide range of sensitive instruments to analyse their contents via optical ports or sampling probes. The accelerator provides an adjustable and precisely measurable beam of 'cosmic rays' that closely matches natural cosmic rays in ionisation density, uniformity and intensity, spanning the atmospheric range from ground level to the maximum around 15 km altitude. In contrast with experiments in the atmosphere, CLOUD is able to compare processes when the cosmic ray beam is varied, and all experimental parameters can be precisely controlled and measured. More information is found at the CLOUD websites
CLOUD is an acronym for Cosmics Leaving OUtdoor Droplets. The scientific objective of CLOUD is to investigate the influence of galactic cosmic rays (GCRs) on ions, aerosols, cloud condensation nuclei (CCN) and clouds, with the CLOUD facility at CERN, and thereby to assess the significance of a possible 'solar indirect' contribution to climate change. Aerosols and clouds are recognised as representing the largest uncertainty in the current understanding of climate change. The Intergovernmental Panel on Climate Change (IPCC) estimates that changes of solar irradiance ('direct solar forcing') have made only a small (7Prozent) contribution to the observed warming. However, large uncertainties remain on other solar-related contributions, such as the effects of changes of galactic cosmic rays on aerosols and clouds. CLOUD aims to settle the important unanswered questions of the IPCC on possible cosmic ray effects on clouds and climate, and to help sharpen our understanding of the anthropogenic contribution to global warming. The scientific programme of CLOUD will involve the establishment of a central CLOUD facility in a beamline (T11) at the CERN Proton Synchrotron accelerator, comprising a large aerosol chamber, within which the atmosphere is recreated from ultra-pure air with added water vapour, trace gases under study and, for certain experiments, aerosols. The chamber will be equipped with a wide range of sensitive instruments to analyse their contents via optical ports or sampling probes. The accelerator provides an adjustable and precisely measurable beam of 'cosmic rays' that closely matches natural cosmic rays in ionisation density, uniformity and intensity, spanning the atmospheric range from ground level to the maximum around 15 km altitude. In contrast with experiments in the atmosphere, CLOUD will be able to compare processes when the cosmic ray beam is varied, and all experimental parameters can be precisely controlled and measured. More information is found at the CLOUD website http://cloud.web.cern.ch/cloud/.