Pui-Wai Ma T.-H. Hubert Chan
We have devised a new type of feedforward neural network. It is equivariant with respect to unitary operators $U(n)$. The input and output can be vectors in $\\mathbb{C}^n$ with arbitrary dimension~$n$. No convolution layer is required in our implementation, and we also avoid errors due to truncated higher order terms in Fourier-like transformat…
Preprint PublishedK. Pentland M. Tamborrino T. J. Sullivan J. Buchanan L. C. Appel
Sequential numerical methods for integrating initial value problems (IVPs) can be prohibitively expensive when high numerical accuracy is required over the entire interval of integration. One remedy is to integrate in a parallel fashion, “predicting” the solution serially using a cheap (coarse) solver and “correcting” these values using an …
PreprintS. H. Ward R. Akers S. D. Pinches A. Loarte R. G. L. Vann M. A. Van Zeeland L. Li Y. Liu A. Polevoi
The LOCUST GPU code has been applied to study the fast-ion transport caused by resonant magnetic perturbations in the high-performance Q = 10 ITER baseline scenario. The computational speed of the code is used calculate the impact of the ITER ELM-control-coil system on neutral beam heating efficiency, as well as producing detailed predictions o…
Preprint PublishedAnder Gray Scott Ferson Edoardo Patelli
Elementary formulas for propagating information about means and variances through mathematical expressions have long been used by analysts. Yet the precise implications of such information are rarely articulated. This paper explores distribution-free techniques for risk analysis that do not require simulation, sampling or approximation of any kind.…
Preprint PublishedK. Pentland M. Tamborrino D. Samaddar L. C. Appel
Parareal is a well-studied algorithm for numerically integrating systems of time-dependent differential equations by parallelising the temporal domain. Given some initial values at each temporal sub-interval, the algorithm iteratively locates a solution in a fixed number of iterations using a predictor-corrector, stopping once a tolerance is met. T…
Preprint PurchaseHelen Brooks Stephen Dixon Andrew Davis
We present new two applications, AURORA and Achlys, developed using the MOOSE framework for finite element analysis, intended to facilitate engineering analysis for fusion reactors. Respectively these couple neutronics and tritium transport to native MOOSE physics modules including heat conduction and tensor mechanics. We outline steps taken to pe…
PreprintS.J.P.PamelaG.T.A.HuijsmansM.Hoelzl
As the international tokamak ITER is being built, non-linear MHD simulations are playing an essential role in active research, understanding, and prediction of tokamak plasmas for the realisation of a fusion power plant. The development of MHD codes like JOREK is a key aspect of this research effort, and provides invaluable insight into the plasma …
PreprintGerald Pintsuk Giaocomo Aiello Sergei L. Dudarev Michael Gorley Jean Henry Marianne Richou Michael Rieth D. Terentyev Rafael Vila
The EUROfusion materials research program for DEMO in-vessel components aligns with the European Fusion Roadmap and comprises the characterization and qualification of the in-vessel baseline materials EUROFER97, CuCrZr and tungsten, advanced structural and high heat flux materials developed for risk mitigation, as well as optical and dielectric fun…
Preprint PublishedL. Reali M. Boleininger M. R. Gilbert S. L. Dudarev
Using the notion of eigenstrain produced by the defects formed in a material exposed to high energy neutron irradiation, we develop a method for computing macroscopic elastic stress and strain arising in components of a fusion power plant during operation. In a microstructurally isotropic material, the primary cause of macroscopic elastic stress an…
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