ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Human Factors, Instrumentation & Controls
Improving task performance, system reliability, system and personnel safety, efficiency, and effectiveness are the division's main objectives. Its major areas of interest include task design, procedures, training, instrument and control layout and placement, stress control, anthropometrics, psychological input, and motivation.
Meeting Spotlight
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Proving DRACO will deliver
The United States is now closer than it has been in over five decades to launching the first nuclear thermal rocket into space, thanks to DRACO—the Demonstration Rocket for Agile Cislunar Orbit.
R. M. Mayo
Fusion Science and Technology | Volume 30 | Number 3 | December 1996 | Pages 1326-1331
Innovative Approaches to Fusion Energy | doi.org/10.13182/FST96-A11963132
Articles are hosted by Taylor and Francis Online.
As a member of the compact toroidal class of magnetic fusion devices, the spheromak [Nucl. Fusion 19, 489 (1979)] offers substantial advantage as a fusion reactor concept over larger, more complicated, and more costly re-entrant devices like the tokamak. The compact and simply closed geometry affording high energy density, the inherent diverted nature of the magnetic topology, the force free condition μ0j(r) = ƛ(ϕ)B(r) nature of the spheromak equilibrium minimizing external coil requirements and stresses, and the possibility of Ohmic ignition resulting from the majority of confining fields generated by internal plasma currents in the spheromak, are a few of the more prominent advantages that represent substantial improvement over conventional magnetic fusion reactor designs. Further, recent successes in improving confinement parameters (Te ~ 400eV, Ti ~ 1keV, ne ~ 3 × 1014cm-3, B ~ 1T) have renewed the interest in advancing this concept to a proof-of-principle, reactor prototype stage.
Here we extend the initial work by Fowler, et al. [Comments Plasma Phys. Controlled Fusion 16, 91 (1994)] indicating the possibility of Ohmic ignition in spheromaks, to a two fluid model that includes direct ion heating through turbulent Taylor relaxation mechanisms. The contribution to direct ion heating through this non-Ohmic magnetic dissipation, and confinement scaling are quantified through comparison with the latest results from the gun driven Compact Torus eXperiment (CTX) [Phys. Fluids B 2, 1342 (1990)] spheromak. We realize good agreement between experimentally measured plasma parameters and our model predictions. Extrapolation to an ignition class experiment is examined indicating the possibility of reaching these conditions by gun driven Ohmic heating alone, and illustrating the merits of direct ion heating on facilitating approach to ignition. Differences between classical (no direct ion heating) and direct ion heating cases are emphasized. Conservative confinement estimates are used throughout.