Search NASA⌕ Search
Home/Archive/DOE OSTI

DOE OSTI · 3030193

Omnigenous stellarators with improved ideal and kinetic ballooning stability

Gaur, R. [Princeton University, NJ (United States)] (ORCID:0000000343679052)·Conlin, R. [University of Maryland, College Park, MD (United States)] (ORCID:0000000183662111)·Dickinson, D. [University of York (United Kingdom)] (ORCID:000000020868211X)·Parisi, J. F. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000313287154)·Panici, D. [Princeton University, NJ (United States)] (ORCID:0000000307364360)·Dudt, D. [Thea Energy, Kearny Point, NJ (United States)] (ORCID:0000000245573529)·Kim, P. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000332011831)·Unalmis, K. [Princeton University, NJ (United States)] (ORCID:0000000217556764)·Dorland, W. D. [University of Maryland, College Park, MD (United States)] (ORCID:000000032915724X)·Kolemen, E. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000342123247)
View original source ↗Read source document ↗Export metadata ↓

Abstract

Omnigenity is a property of a magnetic field which ensures confinement of trapped particles. It is a necessary requirement for any high-performance stellarator. After creating an omnigenous equilibrium, one must also ensure reduced transport resulting from kinetic and magnetohydrodynamic (MHD) instabilities. To this end, we leverage the GPU-accelerated DESC optimization suite, which is used to design stable, finite-β omnigenous equilibria with poloidal, toroidal, and helical symmetry, achieving Mercier, ideal ballooning, and as a consequence, improved kinetic ballooning stability. We discover stellarators with second stability, a regime of large pressure gradient where an equilibrium becomes ideal ballooning stable, and demonstrate and explore both using theory and gyrokinetic simulations the connection between ideal and kinetic ballooning stability.

Explore related subjects

optimizationstabilitystellaratorturbulence

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Gaur, R. [Princeton University, NJ (United States)] (ORCID:0000000343679052), Conlin, R. [University of Maryland, College Park, MD (United States)] (ORCID:0000000183662111), Dickinson, D. [University of York (United Kingdom)] (ORCID:000000020868211X), Parisi, J. F. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000313287154), Panici, D. [Princeton University, NJ (United States)] (ORCID:0000000307364360), Dudt, D. [Thea Energy, Kearny Point, NJ (United States)] (ORCID:0000000245573529), Kim, P. [Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000332011831), Unalmis, K. [Princeton University, NJ (United States)] (ORCID:0000000217556764), Dorland, W. D. [University of Maryland, College Park, MD (United States)] (ORCID:000000032915724X), Kolemen, E. [Princeton University, NJ (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)] (ORCID:0000000342123247). 2025-12-23. Omnigenous stellarators with improved ideal and kinetic ballooning stability. https://doi.org/10.1088/1361-6587%2Fae1e9e

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

NASA NTRS2019

A Design Methodology for Optimizing and Integrating Composite Materials in Gear Structures

The application of composite materials to gear structures is complex because of the gear shape, the need for precise dimensional tolerances, and the complex dynamic load condition. Methods are presented in this work to design and optimize an integrated composite hub-web structure that can be used as part of a hybrid composite-steel gear. The composite hub-web structure is a planar structure with a large decrease in thickness from the hub to the rim. Methods for design and optimization of this variable-thickness structure are presented along with a method for forming braided prepreg material to conform to the shape of this structure. A layered approach is presented that integrates cut plies or filler materials for thickness buildup with continuous-fiber layers for the primary load path. An additional gear design concept is presented that has an axially extended continuous-fiber composite structure that can be combined with the planar structure. A proposed optimization methodology is introduced where an optimized design is output for each type of optimization simulation. Through this process, composite knowledge can be incorporated in the optimization, and more control is given over the design during the process. The methods in this study provide a tool for designing and optimizing composite structures for gears and other high-power-density applications.

optimization↗
NASA NTRS2017

A Smoothed Eclipse Model for Solar Electric Propulsion Trajectory Optimization

Solar electric propulsion (SEP) is the dominant design option for employing low-thrust propulsion on a space mission. Spacecraft solar arrays power the SEP system but are subject to blackout periods during solar eclipse conditions. Discontinuity in power available to the spacecraft must be accounted for in trajectory optimization, but gradient-based methods require a differentiable power model. This work presents a power model that smooths the eclipse transition from total eclipse to total sunlight with a logistic function. Example trajectories are computed with differential dynamic programming, a second-order gradient-based method.

optimization↗