Franco Cozzani | Joint Research Centre (original) (raw)

Papers by Franco Cozzani

Transforming Government: People, Process and Policy, 2015

Purpose – The purpose of this paper is to present an innovative in-house knowledge management sys... more Purpose – The purpose of this paper is to present an innovative in-house knowledge management system of core know-how for European Commission (EC) officials. It shows how the quality of the work of officials could be improved and how talent growth and recognition could be better fostered within the EC, taken as target for the proposal, as well as example for other large, multi-disciplinary organisations that might wish to implement a similar system. Design/methodology/approach – The study considered what the key issues for better knowledge management in the EC are, and what could be learnt from the successful implementation of Diplopedia, the knowledge wiki of the US Department of State, and from previous studies of author rank, quality and stability of individual entries in the public Wikipedia. The less known Citizendium wiki was also considered. Adopting a design science approach, a first conceptual design for a EC-wide in-house knowledge wiki was developed and validated through ...

The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode ... more The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode in the collisional regime is investigated analytically. In the appropriate parameter regime, a new unstable mode, driven by equilibrium current, is found and its relevance to tokamak discharges is discussed.

Journal of Plasma Physics, 1986

The transport theory of a high-energy ion species injected isotropically in a magnetized plasma i... more The transport theory of a high-energy ion species injected isotropically in a magnetized plasma is considered for arbitrary ratios of the high-energy ion cyclotron frequency to the collisional slowing down time. The assumptions of (i) low fractional density of the high-energy species and (ii) average ion speed faster than the thermal ions and slower than the electrons are used to decouple the kinetic equation for the high-energy species from the kinetic equations for background ions and electrons. The kinetic equation is solved by a Chapman–Enskog expansion in the strength of the gradients; an equation for the first correction to the lowest-order distribution function is obtained without scaling a priori the collision frequency with respect to the gyrofrequency. Various transport coefficients are explicitly calculated for the two cases of a weakly and a strongly magnetized plasma.

Fusion Engineering and Design, 2000

For the future fusion materials development program it is necessary to have a dedicated high inte... more For the future fusion materials development program it is necessary to have a dedicated high intensity neutron source available. IFMIF, an accelerator-based intense D-Li neutron source that produces neutrons with a suitable energy spectrum at high intensity and sufficient irradiation volume, is a near term feasible concept which fulfills all essential requirements of the fusion materials development program defined by the users community. IFMIF performs all necessary kinds of material tests with high flexibility in the materials test matrix and the very attractive capability of accelerated irradiations up to about 50 dpa per full power year.

Physics of Fluids, 1987

The local effect of the equilibrium current on the linear stability of low poloidal number tearin... more The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in the collisional regime is investigated analytically. The set of eigenmode equations describing the relevant mode dynamics inside the tearing layer, including the local effect of the equilibrium current, is solved variationally to derive the dispersion relations for the m≥2 and m=1 tearing modes. The local effect of the equilibrium current is found to increase the well‐known FKR growth rate for the classical tearing mode, to enhance stabilization for the m≥2 drift‐tearing mode, and to slightly increase the growth rate for the m=1 mode.

The local effect of the equilibrium current on the linear stability of low poloidal number tearin... more The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in tokamaks is investigated analytically. The plasma response inside the tearing layer is derived from fluid theory and the local equilibrium current is shown to couple to the mode dynamics through its gradient, which is proportional to the local electron temperature gradient under the approximations used in the analysis. The relevant eigenmode equations, expressing Ampere's law and the plasma quasineutrality condition, respectively, are suitably combined in a single integral equation, from which a variational principle is formulated to derive the mode dispersion relations for several cases of interest. The local equilibrium current is treated as a small perturbation of the known results for the m (GREATERTHEQ) 2 and the m = 1 tearing modes in the collisional regime, and the m (GREATERTHEQ) 2 tearing mode in the semi-collisional regime; its effect is found to enhance stabilization for the m (GREATERTHEQ) 2 drift-tearing mode in the collisional regime, whereas the m = 1 growth rate is very slightly increased and the stabilizing effect of the parallel thermal conduction on the m (GREATERTHEQ) 2 mode in the semi-collisional regime is slightly reduced. The possibility of new modes, which do not exist in the absence of local current, is also discussed, but no relevant result is found in this case.

Journal of Plasma Physics, 1986

It is widely agreed that the development of materials for fusion systems requires a high flux, 14... more It is widely agreed that the development of materials for fusion systems requires a high flux, 14 MeV neutron source. The European Union, Japan, Russia and the U.S. have initiated the conceptual design of such a facility. This activity, under the International Energy Agency (IEA) Fusion Materials Agreement, will develop the design for an accelerator-based D-Li system. The first organizational meeting was held in June 1994. This paper describes the system to be studied and the approach to be followed to complete the conceptual design by early 1997.

The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode ... more The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode in the collisional regime is investigated analytically. In the appropriate parameter regime, a new unstable mode, driven by equilibrium current, is found and its relevance to tokamak discharges is discussed.

Physics of Fluids, 1987

The local effect of the equilibrium current on the linear stability of low poloidal number tearin... more The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in the collisional regime is investigated analytically. The set of eigenmode equations describing the relevant mode dynamics inside the tearing layer, including the local effect of the equilibrium current, is solved variationally to derive the dispersion relations for the m≥2 and m=1 tearing modes. The local effect of the equilibrium current is found to increase the well-known FKR growth rate for the classical tearing mode, to enhance stabilization for the m≥2 drift-tearing mode, and to slightly increase the growth rate for the m=1 mode.

Transforming Government: People, Process and Policy, 2015

Purpose – The purpose of this paper is to present an innovative in-house knowledge management sys... more Purpose – The purpose of this paper is to present an innovative in-house knowledge management system of core know-how for European Commission (EC) officials. It shows how the quality of the work of officials could be improved and how talent growth and recognition could be better fostered within the EC, taken as target for the proposal, as well as example for other large, multi-disciplinary organisations that might wish to implement a similar system. Design/methodology/approach – The study considered what the key issues for better knowledge management in the EC are, and what could be learnt from the successful implementation of Diplopedia, the knowledge wiki of the US Department of State, and from previous studies of author rank, quality and stability of individual entries in the public Wikipedia. The less known Citizendium wiki was also considered. Adopting a design science approach, a first conceptual design for a EC-wide in-house knowledge wiki was developed and validated through ...

The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode ... more The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode in the collisional regime is investigated analytically. In the appropriate parameter regime, a new unstable mode, driven by equilibrium current, is found and its relevance to tokamak discharges is discussed.

Journal of Plasma Physics, 1986

The transport theory of a high-energy ion species injected isotropically in a magnetized plasma i... more The transport theory of a high-energy ion species injected isotropically in a magnetized plasma is considered for arbitrary ratios of the high-energy ion cyclotron frequency to the collisional slowing down time. The assumptions of (i) low fractional density of the high-energy species and (ii) average ion speed faster than the thermal ions and slower than the electrons are used to decouple the kinetic equation for the high-energy species from the kinetic equations for background ions and electrons. The kinetic equation is solved by a Chapman–Enskog expansion in the strength of the gradients; an equation for the first correction to the lowest-order distribution function is obtained without scaling a priori the collision frequency with respect to the gyrofrequency. Various transport coefficients are explicitly calculated for the two cases of a weakly and a strongly magnetized plasma.

Fusion Engineering and Design, 2000

For the future fusion materials development program it is necessary to have a dedicated high inte... more For the future fusion materials development program it is necessary to have a dedicated high intensity neutron source available. IFMIF, an accelerator-based intense D-Li neutron source that produces neutrons with a suitable energy spectrum at high intensity and sufficient irradiation volume, is a near term feasible concept which fulfills all essential requirements of the fusion materials development program defined by the users community. IFMIF performs all necessary kinds of material tests with high flexibility in the materials test matrix and the very attractive capability of accelerated irradiations up to about 50 dpa per full power year.

Physics of Fluids, 1987

The local effect of the equilibrium current on the linear stability of low poloidal number tearin... more The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in the collisional regime is investigated analytically. The set of eigenmode equations describing the relevant mode dynamics inside the tearing layer, including the local effect of the equilibrium current, is solved variationally to derive the dispersion relations for the m≥2 and m=1 tearing modes. The local effect of the equilibrium current is found to increase the well‐known FKR growth rate for the classical tearing mode, to enhance stabilization for the m≥2 drift‐tearing mode, and to slightly increase the growth rate for the m=1 mode.

The local effect of the equilibrium current on the linear stability of low poloidal number tearin... more The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in tokamaks is investigated analytically. The plasma response inside the tearing layer is derived from fluid theory and the local equilibrium current is shown to couple to the mode dynamics through its gradient, which is proportional to the local electron temperature gradient under the approximations used in the analysis. The relevant eigenmode equations, expressing Ampere's law and the plasma quasineutrality condition, respectively, are suitably combined in a single integral equation, from which a variational principle is formulated to derive the mode dispersion relations for several cases of interest. The local equilibrium current is treated as a small perturbation of the known results for the m (GREATERTHEQ) 2 and the m = 1 tearing modes in the collisional regime, and the m (GREATERTHEQ) 2 tearing mode in the semi-collisional regime; its effect is found to enhance stabilization for the m (GREATERTHEQ) 2 drift-tearing mode in the collisional regime, whereas the m = 1 growth rate is very slightly increased and the stabilizing effect of the parallel thermal conduction on the m (GREATERTHEQ) 2 mode in the semi-collisional regime is slightly reduced. The possibility of new modes, which do not exist in the absence of local current, is also discussed, but no relevant result is found in this case.

Journal of Plasma Physics, 1986

It is widely agreed that the development of materials for fusion systems requires a high flux, 14... more It is widely agreed that the development of materials for fusion systems requires a high flux, 14 MeV neutron source. The European Union, Japan, Russia and the U.S. have initiated the conceptual design of such a facility. This activity, under the International Energy Agency (IEA) Fusion Materials Agreement, will develop the design for an accelerator-based D-Li system. The first organizational meeting was held in June 1994. This paper describes the system to be studied and the approach to be followed to complete the conceptual design by early 1997.

The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode ... more The effect of the parallel equilibrium current on the linear stability of the drift-tearing mode in the collisional regime is investigated analytically. In the appropriate parameter regime, a new unstable mode, driven by equilibrium current, is found and its relevance to tokamak discharges is discussed.

Physics of Fluids, 1987

The local effect of the equilibrium current on the linear stability of low poloidal number tearin... more The local effect of the equilibrium current on the linear stability of low poloidal number tearing modes in the collisional regime is investigated analytically. The set of eigenmode equations describing the relevant mode dynamics inside the tearing layer, including the local effect of the equilibrium current, is solved variationally to derive the dispersion relations for the m≥2 and m=1 tearing modes. The local effect of the equilibrium current is found to increase the well-known FKR growth rate for the classical tearing mode, to enhance stabilization for the m≥2 drift-tearing mode, and to slightly increase the growth rate for the m=1 mode.