[en] The Big Dee modification project has completed the basic physics design and conceptual engineering design phase and is beginning detailed engineering. The project is funded in FY83 for completing most of the detailed design and placing orders for long lead components and systems. This paper summarizes the conceptual engineering design, especially of the vessel itself

[en] The Doublet III tokamak facility is presently undergoing an upgrade to Big Dee, a device projected to be capable of producing plasmas with parameters approaching breakeven conditions, albeit in hydrogen plasmas. The goal of the upgrade has been to develop a facility capable of studying confinement and beta in non-circular discharges at parameters near breakeven conditions while maintaining the flexibility and accessibility necessary to allow a wide range of problems to be addressed. The upgrade replaces the vacuum vessel and outermost plasma shaping coils allowing higher plasma currents and improved access

[en] The Doublet III facility represents a unique opportunity to convert an existing device to a powerful test bed for FED design and operation issues. Such a conversion is made possible by virtue of the demountability of the devices toroidal field coils. Doublet III can be partially disassembled then reassembled with a large dee-shaped vacuum vessel and associated poloidal coils and structure. Doublet III presently possesses or is acquiring adequate auxiliary heating (14 MW of neutral beams and 2 MW of ECH), stored energy (3 GJ), and power conversion equipment (some added field shaping power equipment is required) to support large dee, reactor-level, plasma experiments. The only modifications required of the device are those directly caused by installing a larger vessel - the vessel itself (and its internal protection system); poloidal field coils that interfere with the larger vessel; and a support system for the new vessel and coils

[en] The principal thrust of the project was to examine a single design in enough depth to gain confidence in the feasibility and desirability of specific design features. However, a valuable spin-off of the project was to develop information of a more generic character to aid in future studies of possibilities for Doublet III. For example, we now feel that Doublet III can be reconfigured with any of a variety of new vacuum vessels, poloidal coil sets, and auxiliary heating systems within three years of project initiation, a period that is short compared to the time scale for developing a completely new facility. In addition, this can be accomplished at a fraction of the cost required to develop a comparable facility

[en] An anti-torque structure is described that meets all the design criteria and involves a minimum of structural redundancy, utilizes ordinary manufacturing techniques, and incorporates adjustability

[en] The DIII-D tokamak at GA Technologies began plasma operation in February of 1986 and is dedicated to the study of highly non-circular plasmas. High beta operation with enhanced energy confinement is paramount among the goals of the DIII-D research program. Commissioning of the device and facility has verified the design capability including coil and vessel loading, volt-second consumption, bakeout temperature, vessel armor, and neutral beamline thermal integrity and control systems performance. Initial experimental results demonstrate the DIII-D is capable of attaining high confinement (H-mode) discharges in a divertor configuration using modest neutral beam heating or ECH. Record values of I/sub p/aB/sub T/ have been achieved with ohmic heating as a first step toward operation at high values of toroidal beta and record values of beta have been achieved using neutral beam heating. This paper summarizes results to date and gives the near term plans for the facility. 13 refs., 6 figs., 1 tab

[en] The US/Japan agreement provided for sharing of Doublet III experimental time between scientific teams from GA and the Japan Atomic Energy Research Institute (JAERI), and also provided for upgrading the experimental capabilities of Doublet III with additional power systems, plasma heating capability, and plasma diagnostic systems

[en] Fusion, the nuclear engine that powers the sun and stars, has been pursued by scientists for decades as the ultimate source of energy. It promises an almost inexhaustible fuel supply with the oceans containing sufficient fusion fuel to outlast the expected life of the sun. Fusion is a process whose waste is inert and whose components know no geographical bounds. Scientists have pondered the laws governing the fusion process since the 1940's, and since the late 1950's laboratory devices have been constructed to test and further develop the theories. To achieve fusion, the joining of light atomic nuclei (as opposed to the splitting of heavy elements in the fission process), the natural tendency of the nuclei to repel each other due to their like electrical charges must be overcome. As the fusion takes place, some of the matter of the nuclei is converted to energy. In the stars fusion is accomplished largely by enormous gravitational forces. On earth the fusion fuel must be heated by other means to increase the energy of the particles to force them to fuse. Therein lies the challenge of fusion research - how to heat sufficient matter to hundreds of millions of degrees and contain it long enough for a controlled and sustained fusion reaction to take place. The method that presently shows the most promise is to contain a plasma (an ionized gas - the fourth state of matter) in a magnetic field while heating the plasma by means of high energy neutral particle beams or radio frequency waves

[en] The Doublet III tokamak is to be modified wherein the original 'doublet' plasma containment vacuum vessel will be exchanged with one of a large dee-shaped cross section. The basic dimensions of the dee vessel will allow plasmas of 1.7-m major radius, 0.7-m minor radius, and a vertical elongation of 1.8. Installation of a large dee vessel in Doublet III is made possible by the demountable toroidal field coils and the large, low-ripple volume they include. Ripple at the plasma edge will be less than one percent. The plasma parameters affecting the design of the vessel will be reviewed including plasma current, power, disruption time, allowable error field, impurity control techniques, pulse length, and limiter schemes. A driving requirement for the design of the vessel is to maximize the access to the plasma for auxiliary heating (both neutral beam injection and radio frequency heating), diagnostics, developmental component and material testing, and pumping. The dee vessel is structurally designed along the same lines as the present vessel: an Inconel 625, all-welded, continuous chamber in a corrugated sandwich construction. An overview of the vessel design and its solutions to the design criteria will be presented. An overview will also be presented of the entire modification project which includes replacement of some coils, and addition of support structure, limiters and vessel armor, and power system components

[en] The Doublet III tokamak facility is presently undergoing an upgrade to Big Dee, a device projected to be capable of producing plasmas with parameters approaching breakeven conditions, albeit in hydrogen plasmas. The goal of the upgrade has been to develop a facility capable of studying confinement and beta in non-circular discharges at parameters near breakeven conditions while maintaining the flexibility and accessibility necessary to allow a wide range of problems to be addressed. The upgrade replaces the vacuum vessel and outermost plasma shaping coils allowing higher plasma currents and improved access