Development of Spectral and Atomic Models for Diagnosing Energetic Particle Characteristics in Fast Ignition Experiments

Period of Performance: 01/01/2006 - 12/31/2006

$750K

Phase 2 STTR

Recipient Firm

Prism Computational Sciences, Inc.
455 Science Drive Suite 140
Madison, WI 53711
Principal Investigator

Research Institution

University of Nevada, Reno
University of Nevada, Reno Mailstop 325
Reno, NV 89557
Institution POC

Abstract

In the fast ignition concept for inertial fusion energy, high-intensity short-pulse lasers are used to create energetic particles (protons and relativistic electrons) that propagate to the fuel within a compressed capsule. The efficient transport of these energetic particles to the fuel is a key issue in fast ignition research. A combination of well-diagnosed experiments and well-tested simulation tools are needed in order to understand energetic particle transport through dense plasmas, a prerequisite for fast ignition to become a viable option for inertial fusion. This project will develop and apply spectral and atomic physics models, used in concert with a particle-in-cell (PIC) code, to simulate diagnostic signatures associated with energetic particle transport in short-pulse laser experiments. The developed models will be applied to fast-ignition-related short-pulse-laser experiments to characterize the properties of energetic electrons and protons. Phase I developed and benchmarked cross section models for energetic protons and relativistic electrons, and utilized them in a collisional-radiative code; developed an interface for post-processing simulation results; developed and initiated a plan to utilize more accurate ionization modeling in PIC code simulations; and performed proof-of-principal simulations relevant to short-pulse laser experiments. Phase II will: (1) develop diagnostics for characterizing energetic particle distributions based on polarization spectroscopy; (2) develop atomic physics modules for use within PIC codes; (3) implement high-fidelity, Stark-broadened line profiles in a multi-dimensional spectral analysis code, in order to provide accurate spectral diagnostics based on inner-shell transitions; and (4) benchmark the new models by comparison with well-diagnosed short-pulse laser experiments. Commercial Applications and other Benefits as described by the awardee: Beyond the application to fast ignition concepts for inertial fusion energy, powerful, user-friendly computational tools, capable of simulating the spectroscopic and atomic properties of laser-produced plasmas, should be applicable to radiation sources for EUV and x-ray lithography, plasma radiation sources used in defense research, magnetic fusion energy plasma diagnostics, materials plasma processing, and radiation sources developed for medical physics research and instrumentation.