Proposed magnet system for EBT-P

Since EBT-P, and other EBT devices, depends on having closed field lines for its successful operation, a very tight tolerance (on the order of 6 parts in 10/sup 4/) must be imposed on certain components of the field error. This is a global tolerance that influences the design of each magnet, its leads, the electrical bus, and the relative position of each magnet to its neighbors. This paper discusses the design, and field error analysis of the ORNL reference design for EBT-P

Advantages of iron core in a tokamak

A quantitative comparison of the iron core vs air core concepts was carried out on a preliminary basis by using a representative tokamak reactor design with the following self-consistent reference parameters. In the area of plasma engineering, poloidal field and MHD equilibrium considerations with an unsaturated iron core is discussed. The question of proper poloidal field coils to maintain D-shaped plasmas of relatively high anti ..beta.. (7%) with a saturated iron core is also discussed. Estimates of the required iron core size, volt seconds, magnetic flux and its influence on force loading on the superconducting toroidal field coils are shown. Conceptual designs of the mechanical structure of an iron core device are presented. Favorable impacts on the OH power supply cost and complexity are indicated

Preliminary structural analysis of the toroidal field coils for T-10M

A structural analysis of the T-10M tokamak toroidal field (TF) coil system has been performed. Two TF coil shapes were proposed, one oval and the other circular. Each TF coil system is composed of 24 coils. The oval TF coil system has a 2.4-m major radius with a minor bore diameter of 2.15 m and a major bore diameter of 3.28 m. The circular TF coil system has a 2.5-m major radius with a 2.2-m bore diameter. The cross sections of both TF coil shapes have rectangular dimensions of 0.4 m by 0.26 m with a 0.36-m by 0.22-m winding cavity symmetrically placed within the cross section. The current of each coil is 1.75 MA. Either geometry produces a magnetic field of 3.5 T on axis, 2.4 m from the machine center line. This study reports the results of a cooperative investigation to determine which TF coil shape operates in a minimum stress configuration. The study is a part of the joint U.S.A./U.S.S.R. scientific exchange. The scope of the analysis covers only the in-plane force distribution produced by the magnetic field. Based upon the preceding conditions the oval TF coil shape appears to be superior to the circular TF coil shape. Further, the oval TF coil shape in its present design has a significant safety margin between working and yield stress under normal operating conditions. The circular design, however, is less sensitive to magnetic field perturbations which may be encountered in proof testing

Characterization and conservation of genetic diversity in subdivided populations

We review the available tools for analysing genetic diversity in conservation programmes of subdivided populations. Ways for establishing conservation priorities have been developed in the context of livestock populations, both from the classical population genetic analysis and from the more recent Weitzman's approach. We discuss different reasons to emphasize either within or between-population variation in conservation decisions and the methodology to establish some compromise. The comparison between neutral and quantitative variation is reviewed from both theoretical and empirical points of view, and the different procedures for the dynamic management of conserved subdivided populations are discussed