The Istituto di Fisica del Plasma (IFP) 'Piero Caldirola' belongs to the Department of Energy & Transport of the Italian National Research Council (CNR). IFP is also a Euratom Research Unit of the Italian EURATOM-ENEA Association in the frame of the European R&D Program on Fusion. The primary mission of IFP is to develop physics and technology activities aimed at the implementation of the experimental prototype of the fusion reactor ITER presently under construction at Cadarache (France). During the last thirty years IFP has gained a widely recognized experience in the field of heating and current drive in fusion plasmas by means of high-power millimeter-wave beams that exploit the resonant wave-plasma interaction at the electron cyclotron frequency either to heat the plasma (ECRH) or to drive current in it (ECCD). IFP personnel is since long responsible of the ECRH&CD system of the tokamak FTU at ENEA-Frascati that includes four 140GHz gyrotrons delivering 0.6MW each and is extensively used to perform various kinds of experiments as ! ! besides plasma heating and non-inductive current drive, stabilization of MHD modes, disruption mitigation and plasma start-up. Unfortunately in 2008 practically no experimental campaign was carried out in FTU due to technical problems, but nevertheless the collaboration of IFP with ENEA-Frascati has profitably prosecuted. Extended data analyses have been carried out to interpret previous experiments and the design of the new fast ECRH launcher to be installed on FTU in year 2009 has been completed. A joint activity for the design of the new European 'satellite tokamak' FAST proposed by the Italian Association to the international fusion community has been also pursued. Casting a glance at a wider horizon, 2008 has seen an increasing involvement of IFP personnel in the experimental program of JET, the largest tokamak now in operation not only in the EU but all over the world. In addition to the traditional modeling activity on energy and momentum transport, which has produced new important results, a participation of IFP to the scientific and technological assessment of the feasibility of an ECRH system for JET has been also started, in which IFP provides broad competences both in the relevant physics studies and in the definition of the gyrotron frequency, the transmission lines, and the millimeter-wave launchers. The involvement of IFP in the JET program further included the development of innovative fusion diagnostics, as the oblique ECE diagnostic (OECE) aimed at the measurement of the radiation emitted obliquely by the electrons at their EC resonance, and neutron and gamma-ray spectrometry, this last carried out in collaboration with the University of Milano Bicocca. Worth being stressed is also that in 2008 an experimental program previously carried out in FTU and aimed at demonstrating the potential of ECRH in the mitigation of extremely dangerous phenomena as plasma disruptions was profitably extended to the AUG tokamak at IPP-Garching (Germany), with direct involvement of IFP personnel Among the actions more specifically focused on the procurement of ECRH components for ITER, in 2008 IFP prosecuted the work for the implementation of a millimeter-wave matched calorimetric load with a power handling capability of up to 2MW , an activity that will converge in the 'Fusion for Energy' Grant for the development of a prototype European gyrotron, awarded by the consortium EGYC formed by, besides IFP, CRPP-Lausanne (Switzerland), FZK-Karlsruhe (Germany), HELLAS (Greece) and ENEA. The activity for the optimization of the EC Upper Launcher of ITER and the definition of a strategy for automatic feedback control of neo-tearing modes (NTMs) was also prosecuted in the frame of a European collaboration purposely implemented to respond jointly to the incoming 'Fusion for Energy' Grants. The participation of IFP to the fusion program of the EU extends to the development of fusion-related technologies. In 2008 significant efforts were devoted to more directly orient these activities towards ITER-relevant issues, taking profit of skills previously acquired in applied plasma researches for industries, generally carried out under dedicated external contracts. For instance, plasma-based coating techniques previously developed for industrial applications were successfully applied to deposit thin rhodium layers on various substrates in view of producing highreflectivity mirrors for fusion diagnostics, a new micro-jet device aimed at producing diamond-like carbon films was procured and will be used to develop detectors for 14MeV neutrons, and preliminary investigations on the 'scavenging effect' of nitrogen molecules, aimed at reducing the carbon re-deposition in remote areas of the first wall of a tokamak, were started ! The issues of carbon re-deposition and tritium retention in an ignited plasma are closely related to the dynamics of the dust that progressively accumulates in it. Understanding the mechanisms of dust production and migration in a fusion plasma therefore is of paramount importance to develop tools for the mitigation of their negative effects. This gave new impulse to experimental studies on the dynamics of the plasma dust and for the development of dust diagnostics based on the analysis of density fluctuation spectra, these last carried out in the magnetic cusp device available at IFP in collaboration with the University of Stockholm, the Universita' di Napoli, and ENEA-Frascati. In the effort of reinforcing its role into ITER-relevant technologies, IFP also succeeded in attracting the interest of highly qualified personnel of IENI-CNR and of the Politecnico di Milano on these issues Most of the experimental activities are accompanied by the development of theoretical models and computational tools. In 2008 the traditional modeling studies on the transport of electromagnetic radiation in tokamak plasmas were extensively used to perform predictive studies for ITER scenarios. In addition, first-principle theoretical models describing the NTMs (Neo-classical Tearing Modes) and ITG (Ion Temperature Gradient) instabilities have been improved with the inclusion of new physical effects, which led to reliable predictions on experimental observations. In the field of plasma physics at high energy densities, the development of a first-principle analytical model for the ion acceleration produced by the interaction of an ultra-short relativistically intense laser pulse impinging on a thin solid layer allowed a satisfactory reproduction of the high-energy part of the ion spectra observed in a number of experiments. The implementation of the linear magnetized plasma device GyM, the main scope of which is providing IFP with modern instrumentation for the development of scientific and technological skills in plasma science, was completed in 2008 and the first plasma has been already produced. The design of an RF-excited high-density plasma source based on the use of a ! 28GHz gyrotron delivering ! 15kW CW and capable of providing relatively high fluxes of fully ionized plasma was also pursued in collaboration with IAP-Nizhny Novgorod (Russia). The new instrumentations will make possible plasma physics experiments under conditions of physical similarity with larger fusion devices. Experiments of plasma breakdown and ionization by means of millimeter-wave radiation and the production of energetic charged particles for ion implantation are other significant parts of the scientific program of GyM, together with the training of young researchers during their Master and PhD Thesis, preliminarily to their full involvement in fusion activities. Even more generally, in 2008 IFP has been steadily engaged in training and dissemination activities in the fields of plasma physics and fusion science tutoring Master and PhD students and delivering courses at the Universita' di Milano Bicocca and the Politecnico di Milano. The organization of the exhibition 'Fusion Expo' also relied mostly on IFP personnel. The rapidly evolving scenario that, following the start of the international undertaking ITER-DEMO, will have to be faced in the incoming years by all the fusion laboratories of the EU will deeply affect their life, their funding and their capability of growing qualified human resources. Meanwhile new strategies will be much likely also defined, both in the EU and all over the world, to afford the energy problem. Great opportunities of development will be counterbalanced by risky situations in case of failure of the efforts for taking profit of the chances of growth all this will offer. In this challenging path towards ITER and DEMO, IFP is fully engaged in better exploiting the scientific and technical competences acquired in several strategic fields, as well as the credit and appreciation repeatedly deserved to its personnel by the fusion community, to make still more trenchant its role. Milano, May 15-th 2009 Maurizio Lontano Head of Research Unit IFP-CNR
Activity Report 2008
2009
Abstract
The Istituto di Fisica del Plasma (IFP) 'Piero Caldirola' belongs to the Department of Energy & Transport of the Italian National Research Council (CNR). IFP is also a Euratom Research Unit of the Italian EURATOM-ENEA Association in the frame of the European R&D Program on Fusion. The primary mission of IFP is to develop physics and technology activities aimed at the implementation of the experimental prototype of the fusion reactor ITER presently under construction at Cadarache (France). During the last thirty years IFP has gained a widely recognized experience in the field of heating and current drive in fusion plasmas by means of high-power millimeter-wave beams that exploit the resonant wave-plasma interaction at the electron cyclotron frequency either to heat the plasma (ECRH) or to drive current in it (ECCD). IFP personnel is since long responsible of the ECRH&CD system of the tokamak FTU at ENEA-Frascati that includes four 140GHz gyrotrons delivering 0.6MW each and is extensively used to perform various kinds of experiments as ! ! besides plasma heating and non-inductive current drive, stabilization of MHD modes, disruption mitigation and plasma start-up. Unfortunately in 2008 practically no experimental campaign was carried out in FTU due to technical problems, but nevertheless the collaboration of IFP with ENEA-Frascati has profitably prosecuted. Extended data analyses have been carried out to interpret previous experiments and the design of the new fast ECRH launcher to be installed on FTU in year 2009 has been completed. A joint activity for the design of the new European 'satellite tokamak' FAST proposed by the Italian Association to the international fusion community has been also pursued. Casting a glance at a wider horizon, 2008 has seen an increasing involvement of IFP personnel in the experimental program of JET, the largest tokamak now in operation not only in the EU but all over the world. In addition to the traditional modeling activity on energy and momentum transport, which has produced new important results, a participation of IFP to the scientific and technological assessment of the feasibility of an ECRH system for JET has been also started, in which IFP provides broad competences both in the relevant physics studies and in the definition of the gyrotron frequency, the transmission lines, and the millimeter-wave launchers. The involvement of IFP in the JET program further included the development of innovative fusion diagnostics, as the oblique ECE diagnostic (OECE) aimed at the measurement of the radiation emitted obliquely by the electrons at their EC resonance, and neutron and gamma-ray spectrometry, this last carried out in collaboration with the University of Milano Bicocca. Worth being stressed is also that in 2008 an experimental program previously carried out in FTU and aimed at demonstrating the potential of ECRH in the mitigation of extremely dangerous phenomena as plasma disruptions was profitably extended to the AUG tokamak at IPP-Garching (Germany), with direct involvement of IFP personnel Among the actions more specifically focused on the procurement of ECRH components for ITER, in 2008 IFP prosecuted the work for the implementation of a millimeter-wave matched calorimetric load with a power handling capability of up to 2MW , an activity that will converge in the 'Fusion for Energy' Grant for the development of a prototype European gyrotron, awarded by the consortium EGYC formed by, besides IFP, CRPP-Lausanne (Switzerland), FZK-Karlsruhe (Germany), HELLAS (Greece) and ENEA. The activity for the optimization of the EC Upper Launcher of ITER and the definition of a strategy for automatic feedback control of neo-tearing modes (NTMs) was also prosecuted in the frame of a European collaboration purposely implemented to respond jointly to the incoming 'Fusion for Energy' Grants. The participation of IFP to the fusion program of the EU extends to the development of fusion-related technologies. In 2008 significant efforts were devoted to more directly orient these activities towards ITER-relevant issues, taking profit of skills previously acquired in applied plasma researches for industries, generally carried out under dedicated external contracts. For instance, plasma-based coating techniques previously developed for industrial applications were successfully applied to deposit thin rhodium layers on various substrates in view of producing highreflectivity mirrors for fusion diagnostics, a new micro-jet device aimed at producing diamond-like carbon films was procured and will be used to develop detectors for 14MeV neutrons, and preliminary investigations on the 'scavenging effect' of nitrogen molecules, aimed at reducing the carbon re-deposition in remote areas of the first wall of a tokamak, were started ! The issues of carbon re-deposition and tritium retention in an ignited plasma are closely related to the dynamics of the dust that progressively accumulates in it. Understanding the mechanisms of dust production and migration in a fusion plasma therefore is of paramount importance to develop tools for the mitigation of their negative effects. This gave new impulse to experimental studies on the dynamics of the plasma dust and for the development of dust diagnostics based on the analysis of density fluctuation spectra, these last carried out in the magnetic cusp device available at IFP in collaboration with the University of Stockholm, the Universita' di Napoli, and ENEA-Frascati. In the effort of reinforcing its role into ITER-relevant technologies, IFP also succeeded in attracting the interest of highly qualified personnel of IENI-CNR and of the Politecnico di Milano on these issues Most of the experimental activities are accompanied by the development of theoretical models and computational tools. In 2008 the traditional modeling studies on the transport of electromagnetic radiation in tokamak plasmas were extensively used to perform predictive studies for ITER scenarios. In addition, first-principle theoretical models describing the NTMs (Neo-classical Tearing Modes) and ITG (Ion Temperature Gradient) instabilities have been improved with the inclusion of new physical effects, which led to reliable predictions on experimental observations. In the field of plasma physics at high energy densities, the development of a first-principle analytical model for the ion acceleration produced by the interaction of an ultra-short relativistically intense laser pulse impinging on a thin solid layer allowed a satisfactory reproduction of the high-energy part of the ion spectra observed in a number of experiments. The implementation of the linear magnetized plasma device GyM, the main scope of which is providing IFP with modern instrumentation for the development of scientific and technological skills in plasma science, was completed in 2008 and the first plasma has been already produced. The design of an RF-excited high-density plasma source based on the use of a ! 28GHz gyrotron delivering ! 15kW CW and capable of providing relatively high fluxes of fully ionized plasma was also pursued in collaboration with IAP-Nizhny Novgorod (Russia). The new instrumentations will make possible plasma physics experiments under conditions of physical similarity with larger fusion devices. Experiments of plasma breakdown and ionization by means of millimeter-wave radiation and the production of energetic charged particles for ion implantation are other significant parts of the scientific program of GyM, together with the training of young researchers during their Master and PhD Thesis, preliminarily to their full involvement in fusion activities. Even more generally, in 2008 IFP has been steadily engaged in training and dissemination activities in the fields of plasma physics and fusion science tutoring Master and PhD students and delivering courses at the Universita' di Milano Bicocca and the Politecnico di Milano. The organization of the exhibition 'Fusion Expo' also relied mostly on IFP personnel. The rapidly evolving scenario that, following the start of the international undertaking ITER-DEMO, will have to be faced in the incoming years by all the fusion laboratories of the EU will deeply affect their life, their funding and their capability of growing qualified human resources. Meanwhile new strategies will be much likely also defined, both in the EU and all over the world, to afford the energy problem. Great opportunities of development will be counterbalanced by risky situations in case of failure of the efforts for taking profit of the chances of growth all this will offer. In this challenging path towards ITER and DEMO, IFP is fully engaged in better exploiting the scientific and technical competences acquired in several strategic fields, as well as the credit and appreciation repeatedly deserved to its personnel by the fusion community, to make still more trenchant its role. Milano, May 15-th 2009 Maurizio Lontano Head of Research Unit IFP-CNRI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
