M A Barrios

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The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray(More)
As the yield on implosion shots increases it is expected that the peak x-ray emission reduces to a duration with a FWHM as short as 20 ps for ∼7 × 10(18) neutron yield. However, the temporal resolution of currently used gated x-ray imagers on the NIF is 40-100 ps. We discuss the benefits of the higher temporal resolution for the NIF and present performance(More)
Enriching linguistic resources with domain information has been considered one important target in natural language applications. However, automatic definition extraction of this domain information from specialized resources has revealed certain methodological problems in definition construction. This paper presents some problems encountered in automatic(More)
The purpose of this paper is to describe a data model that has been used in the construction of a lexical database for Spanish. This lexical resource takes the Meaning-Text Theory (MTT) as the theoretical basis, especially lexical functions (LF), which associate a lexical unit (LU) to values that express a specific meaning related to that LF for that LU. We(More)
Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell(More)
The calibration campaign of the National Ignition Facility X-ray Spectrometer (NXS) was carried out at the Omega laser facility. Spherically symmetric, laser-driven, millimeter-scale x-ray sources of K-shell and L-shell emission from various mid-Z elements were designed for the 2-18 keV energy range of the NXS. The absolute spectral brightness was measured(More)
Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165  μm in thickness, 10% and 15% thinner, respectively, than the nominal thickness capsule used throughout the high foot and most of the National Ignition Campaign. These three-shock, high-adiabat, high-foot(More)
X-ray cameras on inertial confinement fusion facilities can determine the velocity and symmetry of target implosions by recording the x-ray emission of a backlighter or the target itself gated as a function of time. To capture targets that undergo ignition and thermonuclear burn, however, cameras with less than 10ps shutter times are needed. Collaboration(More)
We report 3% conversion efficiency of laser energy into Kr K-shell (≈13 keV) radiation, consistent with theoretical predictions. This is ≈10× greater than previous work. The emission was produced from a 4.1-mm-diameter, 4-mm-tall gas pipe target filled with 1.2 or 1.5 atm of Kr gas. 160 of the National Ignition Facility laser beams deposited ≈700 kJ of 3ω(More)
The equation of state (EOS) of materials at extreme temperatures and pressures is of interest to astrophysics, high-energy-density physics, and inertial confinement fusion (ICF). The behavior of hydrocarbon materials at high-pressures (> 1 Mbar) is essential to the understanding of ablator materials for ICF ignition targets. The EOS measurements on CHX(More)