The Istituto di Fisica del Plasma (IFP) "Piero Caldirola", Milan, belongs to the Department of Energy & Transportation of the Italian National Research Council of Italy (CNR). IFP is also a Euratom Research Unit of the EURATOM-ENEA Association in the frame of the European R&D Programme on Fusion. Its primary mission is to develop physics and technology activities for the implementation of the experimental prototype of the fusion reactor ITER, presently under construction in France. The Milan Research Unit consists, besides IFP-CNR, of the Research Groups of University of Milano-Bicocca, of the Milan Polytechnic, and of the two CNR Institutes IENI-Padua and ISC-Florence, collaborating on specific research tasks. During the last thirty years IFP has gained a recognized experience in the field of high-power heating of magnetized fusion plasmas by means of highfrequency electromagnetic (EM) radiation, based on the resonant waveplasma interaction at frequencies equal to the cyclotron frequency of the electrons (Electron Cyclotron Resonant Heating, or ECRH). IFP personnel is responsible of the ECRH system (4 gyrotrons, 0.6 MW each, 140 GHz, pulse duration up to 0.5 s) installed in the Frascati tokamak FTU, which is used to perform various kinds of experiments as bulk plasma heating, non-inductive current drive, plasma breakdown, stabilization of MHD modes, disruption mitigation applications, all issues of primary interest for the ITER programme. In 2009 the traditional collaboration between IFP-CNR and ENEA-Frascati has consisted in carrying out experiments in FTU on ECRH assisted plasma start-up, on ECRH sawtooth stabilization and in the realization of the new fast EC power launcher (in collaboration with Polytechnic of Milan), which is presently under installation in the tokamak. IFP personnel has been also involved in the "FAST Design Team" of the new European "satellite tokamak", proposed from the Italian Association to the European Fusion Community. The 2009 has seen an increasing involvement of IFP personnel into the scientific programme of JET, the world largest EU tokamak. Indeed, besides the traditional modelling activity on energy and momentum transport which has produced new important insights (influence of plasma rotation and of magnetic shear on ion stiffness, role of rotation, rotation gradients, and Te/Ti on ITG threshold, perturbative analysis of momentum transport), IFP has given a fundamental contribution to the scientific and technological assessment of the feasibility of an ECRH system for JET, providing its competences in the relevant physics studies and in the definition of the gyrotron frequency, transmission lines and power launcher, and in the overview of the available gyrotron technology. The participation of IFP to the JET programme comprises also the development of innovative fusion diagnostics like the measurement of the radiation emitted by electrons at their cyclotron harmonics (ECE), and neutron and gamma-ray spectrometry (these latter in collaboration with the University of Milano-Bicocca). In 2009 an experimental demonstration of the measurement of the !-particle energy distribution function from the observation of the "-ray spectra emitted by the fusion reactions in JET has been given. Among the actions specifically aimed at procuring components for the ITER ECRH system, IFP-CNR is actively committed in the development of the matched load for high power millimeter-wave and of the so-called Upper Launcher (UL) of EC power. The implementation of the CW matched calorimetric loads for millimeter-wave power up to 2MW has been carried out under a "Fusion for Energy" Grant awarded by the Consortium EGYC formed by CRPP-CH, FZK-D, HELLAS-GR, ENEA, and IFP-CNR, to develop the prototype of the EU gyrotron. The activity on the optimization of the ECRH UL for ITER, the relevant physics and the development of the automatic feedback control strategy to suppress NTM instabilities have been continued in the frame of a European collaboration. Moreover, experts from the IFP-CNR have participated to the Preliminary Design Review of the ECRH UL held at ITER IO. The IFP participation to the EU Fusion Programme consists also of activities in the field of fusion-related technologies. These activities are carried out in collaboration with the Polytechnic of Milan, IENI-CNR, and ENEA-Frascati, and have been the result of a reorientation of competences previously developed at IFP-CNR, towards ITER relevant problems and carried out under EFDA Tasks. Plasma-based coating techniques, previously developed at IFP for industrial applications, have been applied to thin Rhodium layer deposition on various substrates to investigate the possibility of producing high-reflectivity mirrors for fusion diagnostics. A new micro-jet device aimed at producing diamond-like-carbon films has been characterized and used in different gas atmospheres, Ar, H2, H2/CH4. Investigations on the "scavenging effect" of nitrogen molecules have been prosecuted in order to reduce the carbon re-deposition in remote areas of the first wall. The problems of carbon re-deposition and tritium retention are closely related to that of the dynamics of dust in plasmas. The understanding of the mechanisms of dust production and migration is of primary importance in order to mitigate such issues. Therefore, the experimental studies on dust dynamics and the development of dust diagnostics, based on the analysis of density fluctuation spectra, have been prosecuted in the magnetic cusp device working at IFP, in collaboration with the University of Stockholm, the University of Naples and ENEAFrascati. Finally, most of the research activities carried out at IFP-CNR have been accompanied by the development of theoretical models and computational tools. In the last year the traditional modelling activities on electromagnetic radiation transport in tokamak plasmas have been improved, including new physical effects, and have been used to make predictions on experimental observations. An empirical scaling criterium for plasma boundary in tokamaks has been elaborated and applied to a multi-machine database. The commitment of IFP-CNR in the ITM Task Force has also continued with an active participation to different Projects. In 2009, a collaboration with the Istituto dei Sistemi Complessi of the CNR, Florence, has started aimed at applying Hamiltonian formalisms in modeling of fusion plasmas. Milano, October 4th, 2010 Maurizio Lontano Director of IFP-CNR Head of EURATOM Research Unit
Activity Report 2009
2010
Abstract
The Istituto di Fisica del Plasma (IFP) "Piero Caldirola", Milan, belongs to the Department of Energy & Transportation of the Italian National Research Council of Italy (CNR). IFP is also a Euratom Research Unit of the EURATOM-ENEA Association in the frame of the European R&D Programme on Fusion. Its primary mission is to develop physics and technology activities for the implementation of the experimental prototype of the fusion reactor ITER, presently under construction in France. The Milan Research Unit consists, besides IFP-CNR, of the Research Groups of University of Milano-Bicocca, of the Milan Polytechnic, and of the two CNR Institutes IENI-Padua and ISC-Florence, collaborating on specific research tasks. During the last thirty years IFP has gained a recognized experience in the field of high-power heating of magnetized fusion plasmas by means of highfrequency electromagnetic (EM) radiation, based on the resonant waveplasma interaction at frequencies equal to the cyclotron frequency of the electrons (Electron Cyclotron Resonant Heating, or ECRH). IFP personnel is responsible of the ECRH system (4 gyrotrons, 0.6 MW each, 140 GHz, pulse duration up to 0.5 s) installed in the Frascati tokamak FTU, which is used to perform various kinds of experiments as bulk plasma heating, non-inductive current drive, plasma breakdown, stabilization of MHD modes, disruption mitigation applications, all issues of primary interest for the ITER programme. In 2009 the traditional collaboration between IFP-CNR and ENEA-Frascati has consisted in carrying out experiments in FTU on ECRH assisted plasma start-up, on ECRH sawtooth stabilization and in the realization of the new fast EC power launcher (in collaboration with Polytechnic of Milan), which is presently under installation in the tokamak. IFP personnel has been also involved in the "FAST Design Team" of the new European "satellite tokamak", proposed from the Italian Association to the European Fusion Community. The 2009 has seen an increasing involvement of IFP personnel into the scientific programme of JET, the world largest EU tokamak. Indeed, besides the traditional modelling activity on energy and momentum transport which has produced new important insights (influence of plasma rotation and of magnetic shear on ion stiffness, role of rotation, rotation gradients, and Te/Ti on ITG threshold, perturbative analysis of momentum transport), IFP has given a fundamental contribution to the scientific and technological assessment of the feasibility of an ECRH system for JET, providing its competences in the relevant physics studies and in the definition of the gyrotron frequency, transmission lines and power launcher, and in the overview of the available gyrotron technology. The participation of IFP to the JET programme comprises also the development of innovative fusion diagnostics like the measurement of the radiation emitted by electrons at their cyclotron harmonics (ECE), and neutron and gamma-ray spectrometry (these latter in collaboration with the University of Milano-Bicocca). In 2009 an experimental demonstration of the measurement of the !-particle energy distribution function from the observation of the "-ray spectra emitted by the fusion reactions in JET has been given. Among the actions specifically aimed at procuring components for the ITER ECRH system, IFP-CNR is actively committed in the development of the matched load for high power millimeter-wave and of the so-called Upper Launcher (UL) of EC power. The implementation of the CW matched calorimetric loads for millimeter-wave power up to 2MW has been carried out under a "Fusion for Energy" Grant awarded by the Consortium EGYC formed by CRPP-CH, FZK-D, HELLAS-GR, ENEA, and IFP-CNR, to develop the prototype of the EU gyrotron. The activity on the optimization of the ECRH UL for ITER, the relevant physics and the development of the automatic feedback control strategy to suppress NTM instabilities have been continued in the frame of a European collaboration. Moreover, experts from the IFP-CNR have participated to the Preliminary Design Review of the ECRH UL held at ITER IO. The IFP participation to the EU Fusion Programme consists also of activities in the field of fusion-related technologies. These activities are carried out in collaboration with the Polytechnic of Milan, IENI-CNR, and ENEA-Frascati, and have been the result of a reorientation of competences previously developed at IFP-CNR, towards ITER relevant problems and carried out under EFDA Tasks. Plasma-based coating techniques, previously developed at IFP for industrial applications, have been applied to thin Rhodium layer deposition on various substrates to investigate the possibility of producing high-reflectivity mirrors for fusion diagnostics. A new micro-jet device aimed at producing diamond-like-carbon films has been characterized and used in different gas atmospheres, Ar, H2, H2/CH4. Investigations on the "scavenging effect" of nitrogen molecules have been prosecuted in order to reduce the carbon re-deposition in remote areas of the first wall. The problems of carbon re-deposition and tritium retention are closely related to that of the dynamics of dust in plasmas. The understanding of the mechanisms of dust production and migration is of primary importance in order to mitigate such issues. Therefore, the experimental studies on dust dynamics and the development of dust diagnostics, based on the analysis of density fluctuation spectra, have been prosecuted in the magnetic cusp device working at IFP, in collaboration with the University of Stockholm, the University of Naples and ENEAFrascati. Finally, most of the research activities carried out at IFP-CNR have been accompanied by the development of theoretical models and computational tools. In the last year the traditional modelling activities on electromagnetic radiation transport in tokamak plasmas have been improved, including new physical effects, and have been used to make predictions on experimental observations. An empirical scaling criterium for plasma boundary in tokamaks has been elaborated and applied to a multi-machine database. The commitment of IFP-CNR in the ITM Task Force has also continued with an active participation to different Projects. In 2009, a collaboration with the Istituto dei Sistemi Complessi of the CNR, Florence, has started aimed at applying Hamiltonian formalisms in modeling of fusion plasmas. Milano, October 4th, 2010 Maurizio Lontano Director of IFP-CNR Head of EURATOM Research UnitI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
