Presentations

This page contains the abstracts of presentations for which I have been presenter and/or contributor.

Comparison of one- and two-dimensional simulations of laser driven shock experiments using 1D and 2D HYADES

J. E. Mucino, R. P. Drake, D. Austin, and M. J. Grosskopf

American Physical Society, 50th Annual Meeting of the Division of Plasma Physics, November 17-21, 2008, abstract #JP6.022

Computer simulations play an important role in target design, experimental planning, and diagnostic selection for experiments in high-energy-density physics, such as those performed at the OMEGA laser facility in Rochester, NY, which involve shocks driven by high intensity lasers. These experiments can be modeled using one-dimensional and two-dimensional versions of a Lagrangian radiation-hydrodynamic code, HYADES. The one-dimensional simulations are effective for scaling calculations but cannot account for the lateral flow of mass and/or energy that are present in two dimensions. This study seeks to quantify the extent to which lateral flow of mass and energy affects the evolution of the simulated flow by identifying differences between the one- and two-dimensional pressure, density, and electron temperature profiles. We are assessing these effects both in thin targets that experience post-shock ablative acceleration and thick targets that are not accelerated, for a range of laser intensities.

Relative Characterization of Low-Energy X-Ray Response of Kodak BioMax®-MS (BMS) Photographic Film

J. E. Mucino, M. E. Lowenstern, N. E. Lanier, J. P. Knauer, R. P. Drake, C. C. Kuranz, J. S. Cowan, T. R. Hurry, K. A. Flippo, and S. A. Gaillard

Omega Laser Facility Users Group 2009 Workshop

For the past few decades, the preferred film used for radiography of high energy-density physics (HEDP) experiments has been the high-sensitivity, double emulsion, Kodak Direct Exposure Film® (DEF). This film has been well studied and characterized. [1] However, Kodak has ceased production of the film, resulting in a limited and aging film supply. This has led the inertial confinement fusion (ICF) and HEDP communities to search for a viable alternative. Current collaborative efforts are being aimed into providing an absolute characterization of BMS film. Presented here is a characterization of the response curve of BMS at low energies, using DEF as a standard.

[1] B. L. Henke, J. Y. Uejio, G. F. Stone, C. H. Dittmore, and F. G. Fujiwara, "High-energy x-ray response of photographic films: models and measurement," J. Opt. Soc. Am. B 3, 1540-1550 (1986)

Performance and Characterization of X-ray Detection Devices for Laboratory Astrophysics Research

M. E. Lowenstern, R. P. Drake, N. E. Lanier, E. C. Harding, C. M. Huntington, J. E. Mucino, and A. J. Visco

American Physical Society, 50th Annual Meeting of the Division of Plasma Physics, November 17-21, 2008, abstract #JP6.021

Various detection tools are utilized in laser driven experiments with a focus on Inertial Confinement Fusion and Astrophysics. Amongst them are framing cameras (devices that convert incident x-rays into electrons that are in turn amplified by a microchannel plate (MCP) and detected by a phosphor material) and x-ray films. We have implemented a detached Au transmission photocathode (160 å thick) on a MCP. We have evaluated it using a 1.5 keV Al K-alpha x-ray source, finding an improvement in the effective quantum efficiency combined with a modest decrease in the overall resolution of the detection system. We will also report results of the characterization of AGFA-D7 film using laser generated x-rays.

Low-Divergent, Energetic Electron Beams from Ultra-Thin Foils

T. Kluge, M. Bussmann, S. A. Gaillard, K. A. Flippo, D. C. Gautier, B. B. Gall, T. Lockard, M. E. Lowenstern, J. E. Mucino, Y. Sentoku, K. Zeil, S. D. Kraft, U. Schramm, T. E. Cowan, and R. Sauerbrey

THE 2ND INTERNATIONAL CONFERENCE ON ULTRA-INTENSE LASER INTERACTION SCIENCE. AIP Conference Proceedings, Volume 1209, pp. 51-54 (2010)

In this work we report on a recent experiment where an energetic, well-collimated electron beam has been observed in the laser direction following the short pulse (600 fs) high-intensity laser interaction with ultra-thin solid foils. These results are in contrast to the typical low-energy divergent electrons accompanying ions in the target normal direction usually seen in solid targets. We observe the foils being preheated and expanded by ASE prior to the main pulse which makes them transparent for the laser. The experimental evidence as well as 2D particle-in-cell simulations suggest the excitation of a wakefield that can accelerate electrons to energies of tens of MeV.

65+ MeV Protons from Short-Pulse-Laser Micro-Cone-Target Interactions

S. A. Gaillard, K. A. Flippo, D. C. Gautier, D. T. Offermann, J. B. Workman, F. Archuleta, R. Gonzales, T. Hurry, R. P. Johnson, S. Letzring, D. S. Montgomery, S. M. Reid, T. Shimada, T. Lockard, Y. Sentoku, M. E. Lowenstern, J. E. Mucino, B. B. Gall, E. D'Humieres, M. Geissel, M. Schollmeier, M. Bussmann, T. E. Cowan, T. Kluge, and J. M. Rassuchine

American Physical Society, 51st Annual Meeting of the APS Division of Plasma Physics, November 2-6, 2009, abstract #GO6.003

Two sets of laser-ion acceleration experiments at the LANL 200 TW Trident laser at ~10²⁰ W/cm² (1 μm, 80 J, ~600 fs) with high (>10¹⁰) and low (>10⁸) contrast are compared for regular size flat foils (~2x2 mm), reduced mass targets (RMT, 200-500 μm diameter) and new micro-cone targets in various geometries to elucidate the production of hot electrons and ions in these targets. Results from the latest experiment at high contrast show proton energies in excess of 65 MeV for flat-top cones, compared to ~55 MeV for RMTs and ~45 MeV for flat foils. Data from a Cu Kα 2D imaging crystal, an electron spectrometer and an RCF stack are presented and compared, showing the importance of not just generating hot electrons, but efficiently propagating these hot electrons to the accelerating "tip'', where they can then be converted to ion energy, as well as the importance of the micro-cones' supporting foil size.