Simulation of nanoscale high-efficiency thermionic converters

The design and fabrication of vacuum nano-electronic devices is essential to the present and future US economy and energy sources. Highly-resolved 3D electrostatic particle-in-cell (PIC) simulations are required to correctly model and optimize their fabrication and operation; however, the associated run-time and complexity of such HPC codes is prohibitive. The Scientific Discovery through Advanced Computing (SciDAC) program has contributed to the development of Warp, an open source multi-species 3D PIC code that scales efficiently to many cores and includes many state-of-the-art algorithms, including mesh refinement. With code hardening, and some additional physics and design capabilities, Warp will profoundly impact the vacuum nano-electronics industry. General statement of how this problem is being addressed We will develop a commercial quality GUI for cloud-based execution of Warp on HPC servers, with CAD integration for complex geometries, and with specialized capabilities to design and optimize vacuum nanoelectronic devices, emphasizing thermionic converters for electricity generation. We will demonstrate the capabilities of this interface by optimizing the design of thermionic converters for industrial application. What is to be done in Phase I? We will implement a prototype GUI for electrostatic PIC simulations, based on our open source Sirepo architecture. We will also demonstrate integration of Warp's native geometry handling with a standard CAD format. Third, we will use a state-of-the-art ASCR funded nonlinear optimization library to demonstrate minimization of current loss in a thermionic converter. Finally, we will explore the physics of electrostatic dielectric charging, including all relevant surface physics issues, including charge mobility. Commercial Applications and Other Benefits We will commercialize our open-source scientific application framework Sirepo to provide sophisticated simulation support and consulting services for targeted industry and research partners. The Sirepo platform is designed to support a diverse array of software for modelling plasma physics, beam physics, and nanoscale device multiphysics. Our target customers include start-ups in the vacuum electronics industry looking to model novel nanoscale device designs. In addition to direct sales and presentations at conferences and trade shows, RadiaSoft will build and brand an active online community and a viable ecosystem to support this business model.