[en] Goal was to develop a scaling expression which adequately describes profiles in existing tokamaks and which could be used to predict plasma profile shapes and magnitudes for future devices (such as ITER and TPX) without the need for a plasma transport model. This paper presents a multi-machine feasibility study of this goal. We present an initial assessment of an effort to derive an empirical expression for the normalized plasma electron temperature and electron density profile in terms of global quantities. (Global variables were used since they allowed a large enough database to be assembled for this statistical study.) Data from both JET and DIII-D were obtained in a single-null configuration with an expanded boundary divertor. The density profile parameterization indicates that as the plasma current is increased, the n_e profile broadens and the edge gradient increases; this is consistent with JET and DIII-D operations. The T_e profile broadens as the RF power is deposited farther off-axis. For both T_e and n_e profiles, the DIII-D profiles are more peaked than the JET profiles. The probable ITER profiles are discussed. 3 figs

[en] The torus of the Fusion Engineering Device (FED) provided a plasma chamber with the required vacuum integrity and nuclear shielding to protect personnel and to limit damage to sensitive components. The torus spool is the primary load-carrying structure and serves as the vacuum enclosures on the top, bottom, and inboard wall. A combination of the shield sector outer surface, a bellows seal systems, and the spool comprises the total vacuum system boundary. The inboard shield thickness of 60 cm is sufficient to meet the FED requirements to limit the heating rate in the inboard leg of the TF coils to 5 mW/cm/sup 3/. The 1.2-m-thick outboard shield meets the requirements of limiting personnel exposure to 2.5 mrem/h 24 hours after shutdown from 8-T operation or 2.5 mrem/h 36 hours after shutdown for a limited number of 10-T shots

[en] The reasons to correct or not to correct the global energy confinement time by taking into account the non-absorption due to different loss mechanisms are discussed and the consequences of such correction are examined. In order to alleviate the growing confusion, always state the so-called ''engineering'' definition of the confinement time given by the ratio of plasma energy to total power injected. (Author)

No abstract available

[en] In this paper, the authors consider the strategies pursued to reach thermonuclear ignition and to come from there to an economical fusion reactor. The JET generation of tokamak devices is described as well as the period after JET. The state of affairs of national and international research programs is discussed. (Auth.)

No abstract available

[en] The interest of thermonuclear fusion for energy production is underlined. The present state of the research in this field is presented, emphasis being given to Tokamak configurations. The problems concerning confinement and additional heating in these devices are presented

[en] Electromagnetic aspects in the design of ITER-like reactors call for an extensive use of complex and advanced numerical codes. For this reason a strong attention has been paid within the NET-Team to the code development. In particular, through a cooperation with some Italian universities, during the last years a number of numerical procedures were developed and integrated. In order to assess the code reliability and to gain confidence on their predictions for next generation ITER-like reactors, the validation of the codes against experiments has to be considered as a strict requirement. Aim of this paper is to give a comprehensive presentation of this problem in the light of the results of a campaign of validation runs. The main outcome of this work is that the computational procedures, which have been developed for the NET project and then extensively used also for ITER studies, can be considered as experimentally validated in a sufficiently wide range of cases of interest. In particular, computed values are compared with experimental measurements made during some typical ASDEX-Upgrade discharges. From the electromagnetic point of view, many features of this machine are common to the ITER concept, so that the results of the validation can reasonably be extended to the ITER case. (orig.)

[en] A new theory of astron ion-ring equilibria is developed. In contrast with previous equilibria, the new equilibria have a distribution of canonical momentum which is invariant to axisymmetric changes in the external magnetic field and in the boundary conditions at vessel walls. As a function of the single particle constants of the mation, the energy H and the canonical momentum P/sub theta/, the distribution function, f(H,P/sub theta/), is written as f = g(P/sub theta/) F(H,P/sub theta/) [A(H,P/sub theta)]^-1; where g(P/sub theta/) is the invariant distribution function for canonical momentum; where A(H,P/sub theta/) is the area of the poloidal (r,z) plane accessible to a ring particle with constants H and P/sub theta/, and where F(H,P/sub theta/) is a non negative function having the normalization integral aHF = const. With this representation of f, it becomes possible to study the adiabatic compression of ion-ring Vlasov equilibria

[en] To meet the requirements of the U.S. Stellarator Power Plant Study, a Modular Helias-like Heliac (MHH) configuration was developed that has features in common with a quasihelically symmetric experiment proposed at the University of Wisconsin [D. Anderson and P. Garabedian, Nucl. Fusion 34, 881 (1994)]. Improvements have been made in the design of the MHH that raise the β limit, increase the confinement time, and simplify the geometry of the coils. In particular, specifications have been found for a stellarator with just two field periods that has a magnetic field spectrum B_mn close to axial symmetry. This configuration has physical properties that make it an interesting candidate for a follow-on experiment to assess the equilibrium, stability and transport of advanced stellarators. copyright 1996 American Institute of Physics