Electron impact cross-sections for biomolecules ¿ completeness and selfconsistency via swarm analysis

ICPEAC 2015, Toledo, Spain on 22 –28 July 2015; http://www.icpeac2015.com/The accuracy and completeness of electron impact cross-sections in water and tetrahydrofuran are assessed through comparison with experimental electron transport coefficients using the pulsed Townsend experiment.Peer Reviewe

An improved set of electron-THFA cross sections refined through a neural network-based analysis of swarm data

We review experimental and theoretical cross sections for electron transport in α-tetrahydrofurfuryl alcohol (THFA) and, in doing so, propose a plausible complete set. To assess the accuracy and self-consistency of our proposed set, we use the pulsed-Townsend technique to measure drift velocities, longitudinal diffusion coefficients, and effective Townsend first ionization coefficients for electron swarms in admixtures of THFA in argon, across a range of density-reduced electric fields from 1 to 450 Td. These measurements are then compared to simulated values derived from our proposed set using a multi-term solution of Boltzmann’s equation. We observe discrepancies between the simulation and experiment, which we attempt to address by employing a neural network model that is trained to solve the inverse swarm problem of unfolding the cross sections underpinning our experimental swarm measurements. What results from our neural network-based analysis is a refined set of electron-THFA cross sections, which we confirm is of higher consistency with our swarm measurements than that which we initially proposed. We also use our database to calculate electron transport coefficients in pure THFA across a range of reduced electric fields from 0.001 to 10000 Td

First Measurements of Rayleigh-Taylor-Induced Magnetic Fields in Laser-produced Plasmas

The first experimental demonstration of Rayleigh-Taylor-induced magnetic fields due to the Biermann battery effect has been made. Experiments with laser-irradiated plastic foils were performed to investigate these illusive fields using a monoenergetic proton radiography system. Path-integrated B field strength measurements were inferred from radiographs and found to increase from 10 to 100  T μm during the linear growth phase for 120  μm perturbations. Proton fluence modulations were corrected for Coulomb scattering using measured areal density profiles from x-ray radiographs.United States. Dept. of Energy (grant DE-FG52-09NA29553)University of Rochester. Fusion Science Center (grant 415023-G)University of Rochester. Laboratory for Laser Energetics (grant 414090-G)Lawrence Livermore National Laboratory (grant B580243)National Laser User’s Facility (grant DE-NA0000877