Deep Quantum Circuit Simulations of Low-Energy Nuclear States

Numerical simulation is an important method for verifying the quantum circuits used to simulate low-energy nuclear states. However, real-world applications of quantum computing for nuclear theory often generate deep quantum circuits that place demanding memory and processing requirements on conventional simulation methods. Here, we present advances in high-performance numerical simulations of deep quantum circuits to efficiently verify the accuracy of low-energy nuclear physics applications. Our approach employs several novel methods for accelerating the numerical simulation including 1- and 2-qubit gate fusion techniques as well as management of simulated mid-circuit measurements to verify state preparation circuits. We test these methods across a variety of high-performance computing systems and our results show that circuits up to 21 qubits and more than 115,000,000 gates can be efficiently simulated

Optimization of Nonlinear Turbulence in Stellarators

We present new stellarator equilibria that have been optimized for reduced turbulent transport using nonlinear gyrokinetic simulations within the optimization loop. The optimization routine involves coupling the pseudo-spectral GPU-native gyrokinetic code GX with the stellarator equilibrium and optimization code DESC. Since using GX allows for fast nonlinear simulations, we directly optimize for reduced nonlinear heat fluxes. To handle the noisy heat flux traces returned by these simulations, we employ the simultaneous perturbation stochastic approximation (SPSA) method that only uses two objective function evaluations for a simple estimate of the gradient. We show several examples that optimize for both reduced heat fluxes and good quasisymmetry as a proxy for low neoclassical transport. Finally, we run full transport simulations using T3D to evaluate the changes in the macroscopic profiles

Computational Methods in Science and Engineering : Proceedings of the Workshop SimLabs@KIT, November 29 - 30, 2010, Karlsruhe, Germany

In this proceedings volume we provide a compilation of article contributions equally covering applications from different research fields and ranging from capacity up to capability computing. Besides classical computing aspects such as parallelization, the focus of these proceedings is on multi-scale approaches and methods for tackling algorithm and data complexity. Also practical aspects regarding the usage of the HPC infrastructure and available tools and software at the SCC are presented

Simulación de la evolución de defectos en materiales irradiados de interés en fusión nuclear mediante un método GPU-OKMC

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, leída el 28-11-2022As the current world reliance on fossil fuels proves to have catastrophic environmental consequences, which are only exacerbated with a growing world economy and population, a future clean source of energy is required. The scientific community expects nuclear fusion to fulfill this task, in particular magnetically confined fusion. To achieve this, an experimental fusion reactor, the ITER Project, is underway and shall provide the basis for a future demonstration power plant, known as DEMO. One of the most important challenges in the design of a future nuclear fusion reactor is the choice of materials. Materials are subjected to an intense flux of neutrons and heat in a fusion reactor like ITER or, in a much more pronounced way, DEMO. Under irradiation, a large amount of defects are created and, as aconsequence, the properties of materials are severely degraded, and may cause the reactor components to malfunction or break...Dado que la actual dependencia mundial de los combustibles fósiles muestra ciertas consecuencias catastro cas para el medio ambiente, las cuales son magnificadas a medida que crecen la economía y población mundiales, se necesita una fuente de energía limpia para el futuro. La comunidad científica espera que sea la fusión nuclear la que desempeñe este papel, en particular la fusión por confinamiento magnético. Para ello, un reactor de fusión experimental, el Proyecto ITER, esta en marcha y proporcionará las bases para un futuro reactor de demostración llamado DEMO. Uno de los desafíos principales en el diseño de un futuro reactor de fusión es la elección de los materiales. En efecto, los materiales serán sometidos a un flujo intenso de neutrones y calor en un reactor de fusión como ITER; y, de forma más pronunciada, en uno como DEMO. Esto provocara la creación de una gran cantidad de defectos, por lo que las propiedades de los materiales serán gravemente alteradas, y podrán provocar que los componentes del reactor dejen de funcionar correctamente o, incluso, se quiebren...Fac. de Ciencias FísicasTRUEunpu