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The recently discovered properties of the I-confinement Regime are explained as resulting from the excitation of a heavy particle mode. The theoretically predicted mode phase velocity in the direction of the electron diamagnetic velocity and the induced confinement of impurities at the edge of the plasma column have been confirmed by the experiments. The direction of the mode phase velocity is consistent with that (opposite) of the spontaneous rotation in the plasma core. The mode is of the “ion-mixing” type, in that it does not produce any electron transport across the fields and it involves significant poloidal magnetic field fluctuations., United States. Department of Energy

A hybrid solution is proposed for the IGNITOR research fusion machine by using of superconducting coils for some poloidal magnets, in association with high field copper magnets for the central solenoid and for the toroidal field coils. The choice to be made among the various superconductors is based on the materials performances in high magnetic field, on the mechanical strength of the conductors and on the cost of manufacturing large coils. In this study we analyze a coil based on MgB₂, a "medium temperature" superconducting material that we expect will avoid, in association with others high temperature superconductors, the use of liquid He in future machines. The external poloidal magnet, 5 m in diameter and subjected to a magnetic field of 5 T, represents a real test bench of the technical issues which should be addressed in the exploitation of the future fusion reactors. To fulfil the technical characteristics of the selected magnet we must optimize the fill factor of the superconducting MgB₂ wires, increasing the presently obtained 30% value. Accordingly, the effective current density in the superconducting wire should be of about 1500 A/mm[superscript 2] (@10 K, 5 T), a value which is compatible with the present best MgB₂ laboratory short wires, doped by C or SiC.

The excitation of a novel kind of heavy particle [1, 2] mode at the edge of the plasma column is considered as the signature of the I-con nement Regime [3{7]. The outward transport of impurities produced by this mode is in fact consistent with the observed expulsion of them from the main body of the plasma column (a high degree of plasma purity is a necessary feature for fusion burning plasmas capable of approaching ignition). Moreover, the theoretically predicted mode phase velocity, in the direction of the electron diamagnetic velocity, has been con rmed by relevant experimental analyses [8] of the excited uctuations (around 200 kHz). The plasma \spontaneous rotation" in the direction of the ion diamagnetic velocity is also consistent, according to the Accretion Theory [9] of this phenomenon, with the direction of the mode phase velocity. Another feature of the mode that predicted by the theory is that the I-Regime exhibits a knee of the ion temperature at the edge of the plasma column but not one of the particle density as the mode excitation factor is the relative main ion temperature gradient exceeding the local relative density gradient. The net plasma current density appearing in the saturation stage of the relevant instability, where the induced particle and energy uxes are drastically reduced, is associated with the signi cant amplitudes of the poloidal magnetic eld uctuations [6, 7] observed to accompany the density uctuations. The theoretical implications of the signi cant electron temperature uctuations [10] observed are discussed., United States. Dept. of Energy

The presented theory is motivated by the growing body of experimental information on the characteristics, connected with relevant spectral, time, and space resolutions, of the radiation emission from objects considered as rotating black holes. In the immediate surroundings of these objects, three plasma regions are identified: an innermost Buffer Region, an intermediate Three-regime Region, and a Structured Peripheral Region. In the last region, a Composite Disk Structure made of a sequence of plasma rings corresponding to the formation of closed magnetic surfaces is considered to be present and to allow intermittent accretion flows along the relevant separatrices. The nonlinear “Master Equation” describing composite disk structures is derived and solved in appropriate asymptotic limits. A ring configuration, depending on the state of the plasma at the microscopic level: (i) can be excluded from forming given the strongly nonthermal nature of the electron distribution (in momentum space) within the Three-regime Region allowing the onset of a spiral structure; the observed High Frequency Quasi Periodic Oscillations are associated with these tridimensional structures; (ii) may be allowed to propagate to the outer edge of the Buffer Region where successive rings carrying currents in opposite directions are ejected vertically (in opposite directions) and originate the observed jets; or (iii) penetrates in the Three-regime Region and is dissipated before reaching the outer edge of the Buffer Region. The absence of a coherent composite disk structure guiding accretion in the presence of a significant magnetic field background is suggested to characterize quiescent black holes., United States. Dept. of Energy

ENEA and Oak Ridge National Laboratory (ORNL) are collaborating on the development of a four barrel, two-stage pneumatic injector for the Ignitor experiment, featuring two innovative concepts: (i) the proper shaping of the propellant pressure pulse to improve pellet acceleration, and (ii) the use of fast closing (< 10 ms) valves to drastically reduce the expansion volumes of the propellant gas removal system. Two independent sub-systems have been built and tested separately by ENEA and ORNL. The ENEA equipment has then been shipped to Oak Ridge, where testing of the two coupled systems have started during the last year. The results of the first two short experimental campaigns, jointly carried out by ENEA and ORNL teams (May 12-16 and December 15-19 2008), as well as the latest advancement of this project will be reported.

Contains table of contents for Section 2 and reports on four research projects., Lawrence Livermore National Laboratory Subcontract 6264005, National Science Foundation Grant ECS 84-13173, National Science Foundation Grant ECS 85-14517, U.S. Air Force - Office of Scientific Research Contract AFOSR 84-0026, U.S. Army - Harry Diamond Laboratories Contract DAAL02-86-C-0050, U.S. Navy - Office of Naval Research Contract N00014-87-K-2001, National Science Foundation Grant ECS 85-15032, National Science Foundation Grant ECS 88-22475, U.S. Department of Energy Contract DE-AC02-ET-51013

Contains research objectives and summary of research on eighteen research projects split into seven sections and reports on four research projects., U.S. Atomic Energy Commission (Contract AT(l1-1)-3070), National Science Foundation (Grant GK-37979X1)

Ignitor is a proposed compact high-magnetic field tokamak aimed at studying plasma burning conditions in Deuterium-Tritium plasmas. Localisation of this experiment in Italy has seen growing attention during the last years. The determination to carry out this project in Italy has driven to taking into account several candidate sites. Recently, due to several technical reasons, it was identified a new site, the Caorso Site, in northern Italy, a nuclear site were a nuclear power reactor was sited. Preliminary Radiological Impact analyses for the siting of Ignitor in Caorso are presented in this paper. Te Ignitor radiological impact turns out to be negligible both during normal operation and in case of accident.

The theory of the composite plasma disk structures and of the relevant magnetic field configurations that can surround black holes is presented, consistently with recent experimental observations indicating that highly coherent magnetic field configurations exist in the core of these structures. Concepts developed to describe the physics of magnetically confined laboratory plasmas are used. Thus the “paradox”, that arises when considering accreting plasmas in the presence of a transverse magnetic field is resolved by considering accretion as an intermittent process whereby particles are carried in steps, along a sequence of magnetic separatrices containing the formed magnetic islands, by the onset of the equivalent of “edge localized modes” (ELMs) observed in laboratory experiments. Inactive galactic black holes are suggested as being associated with older galaxies that have been subjected to collisions destroying the coherent structures needed to guide relevant accretion flows. Alternatively, tridimensional spiral structures can emerge from axisymmetric disk configurations in a region close to the black hole and guide the relevant accretion flows. The radial gradient of the rotation frequency and the vertical gradient of the plasma pressure are the excitation factors for spirals as well as for axisymmetric modes. These can produce vertical flows of thermal energy and particles in opposing directions that can be connected to the winds emanating from disks in Active Galactic Nuclei (AGNs). In the close vicinity of Binary Black Holes the existence of three characteristic plasma regions is envisioned. The intermediate of these regions exhibits three physical regimes that differ both for the magnetic field structure and the spectrum of the emitted radiation, with jets and High Frequency Periodic Oscillations (HFQPOs) produced in two of these regimes., United States Department of Energy

The theoretical finding of composite disk structures around compact objects (e.g. black holes) and recent experimental observations indicate that highly coherent and dynamically important magnetic field configurations exist in the core of these plasma structures. Coherent configurations involving closed magnetic surfaces provide a means to resolve the 'accretion paradox' for a magnetized disk while the formation of jets emitted in the close vicinity of the compact object is related to these configurations. The absence of vigorous accretion activity in the presence of black holes in old galaxies can be attributed to the loss of the surrounding coherent magnetic configurations during their history. The relevant dynamics include axisymmetric (ballooning) modes as well as tridimensional spirals which can be excited from disks with a 'seed' magnetic field, under the effects of differential rotation and of the vertical plasma pressure gradient. The properties of these spirals are strongly dependent on their vertical structure. Axisymmetric modes can produce vertical flows of thermal energy and particles in opposing directions that can be connected to the winds emanating from disks in active galactic nuclei (AGNs). A similarity to the effects of temperature gradient driven modes in magnetically confined laboratory plasmas is pointed out. Spiral modes that are oscillatory in time and in the radial direction can produce transport of angular momentum toward the outer region of the disk structure, a necessary process for the occurrence of accretion. The excitation of radially localized density spirals co-rotating with the plasma, at a distance related to the Schwartzchild radius RS = 2GM*/c2, is proposed as the explanation for high frequency quasiperiodic oscillations (HFQPOs) of non-thermal x-ray emission from compact objects., U.S. Department of Energy

Contains research objectives and reports on four research projects., U. S. Atomic Energy Commission (Contract AT(30-1)-3980)

Contains reports on two research projects., U.S. Atomic Energy Commission (Contract AT(30-1)-3980)