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J. Villanueva

Bio: J. Villanueva is an academic researcher from Lawrence Livermore National Laboratory. The author has contributed to research in topics: National Ignition Facility. The author has an hindex of 3, co-authored 3 publications receiving 87 citations.

Papers
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Journal ArticleDOI
TL;DR: The National Ignition Facility (NIF) as discussed by the authors is the world's largest optical instrument, comprising 192 37'cm square beams, each generating up to 9.6'kJ of 351'nm laser light in a 20'ns beam precisely tailored in time and spectrum.
Abstract: The National Ignition Facility (NIF) is the world’s largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum. The Facility houses a massive (10 m diameter) target chamber within which the beams converge onto an ∼1 cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5 m×2 m×1 m) line-replaceable optics assemblies to within ±1 mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10 min and alignment to target chamber center within 44 min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50 μm rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams.

84 citations

24 Aug 2010
TL;DR: The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum.
Abstract: The National Ignition Facility (NIF) is the world's largest optical instrument, comprising 192 37 cm square beams, each generating up to 9.6 kJ of 351 nm laser light in a 20 ns beam precisely tailored in time and spectrum. The Facility houses a massive (10 m diameter) target chamber within which the beams converge onto an ∼1 cm size target for the purpose of creating the conditions needed for deuterium/tritium nuclear fusion in a laboratory setting. A formidable challenge was building NIF to the precise requirements for beam propagation, commissioning the beam lines, and engineering systems to reliably and safely align 192 beams within the confines of a multihour shot cycle. Designing the facility to minimize drift and vibration, placing the optical components in their design locations, commissioning beam alignment, and performing precise system alignment are the key alignment accomplishments over the decade of work described herein. The design and positioning phases placed more than 3000 large (2.5 m×2 m×1 m) line-replaceable optics assemblies to within ±1 mm of design requirement. The commissioning and alignment phases validated clear apertures (no clipping) for all beam lines, and demonstrated automated laser alignment within 10 min and alignment to target chamber center within 44 min. Pointing validation system shots to flat gold-plated x-ray emitting targets showed NIF met its design requirement of ±50 μm rms beam pointing to target chamber. Finally, this paper describes the major alignment challenges faced by the NIF Project from inception to present, and how these challenges were met and solved by the NIF design and commissioning teams.

6 citations

Proceedings ArticleDOI
TL;DR: The National Ignition Facility in Livermore, California, completed it's commissioning milestone on March 10, 2009 when it fired all 192 beams at a combined energy of 1.1 MJ at 351nm, the culmination of 15 years of engineering design of a stable facility, commissioning of precision alignment, and precise shot operations controls.
Abstract: The National Ignition Facility in Livermore, California, completed it's commissioning milestone on March 10, 2009 when it fired all 192 beams at a combined energy of 1.1 MJ at 351nm. Subsequently, a target shot series from August through December of 2009 culminated in scale ignition target design experiments up to 1.2 MJ in the National Ignition Campaign. Preparations are underway through the first half of of 2010 leading to DT ignition and gain experiments in the fall of 2010 into 2011. The top level requirement for beam pointing to target of 50μm rms is the culmination of 15 years of engineering design of a stable facility, commissioning of precision alignment, and precise shot operations controls. Key design documents which guided this project were published in the mid 1990's, driving systems designs. Precision Survey methods were used throughout construction, commissioning and operations for precision placement. Rigorous commissioning processes were used to ensure and validate placement and alignment throughout commissioning and in present day operations. Accurate and rapid system alignment during operations is accomplished by an impressive controls system to align and validate alignment readiness, assuring machine safety and productive experiments.

3 citations


Cited by
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Journal ArticleDOI
TL;DR: The National Ignition Facility (NIF) as discussed by the authors was designed and built to meet the challenges for study of high energy-density physics and inertial confinement fusion (ICF) implosi...
Abstract: The possibility of imploding small capsules to produce mini-fusion explosions was explored soon after the first thermonuclear explosions in the early 1950s. Various technologies have been pursued to achieve the focused power and energy required for laboratory-scale fusion. Each technology has its own challenges. For example, electron and ion beams can deliver the large amounts of energy but must contend with Coulomb repulsion forces that make focusing these beams a daunting challenge. The demonstration of the first laser in 1960 provided a new option. Energy from laser beams can be focused and deposited within a small volume; the challenge became whether a practical laser system can be constructed that delivers the power and energy required while meeting all other demands for achieving a high-density, symmetric implosion. The National Ignition Facility (NIF) is the laser designed and built to meet the challenges for study of high-energy-density physics and inertial confinement fusion (ICF) implosi...

182 citations

Journal ArticleDOI
TL;DR: The conceptual design for laser drivers used in Laser Inertial Fusion Energy (LIFE) power plants is presented and statistical modeling predicts that laser-system availability can be greater than 99% provided that components meet reasonable mean-time-between-failure specifications.
Abstract: This paper presents our conceptual design for laser drivers used in Laser Inertial Fusion Energy (LIFE) power plants. Although we have used only modest extensions of existing laser technology to en...

73 citations

Journal ArticleDOI
TL;DR: The National Ignition Facility (NIF) is the culmination of more than 40 years of work at Lawrence Livermore National Laboratory dedicated to the delivery of laser systems capable of driving electric vehicles.
Abstract: The National Ignition Facility (NIF) laser is the culmination of more than 40 years of work at Lawrence Livermore National Laboratory dedicated to the delivery of laser systems capable of driving e...

67 citations

Journal ArticleDOI
Xian Tao1, De Xu1, Zhengtao Zhang1, Feng Zhang1, Xilong Liu1, Dapeng Zhang1 
TL;DR: This method can detect multiple types of weak scratches in complex images and that the defects can be correctly distinguished with interference, and satisfies the real-time and accurate detection requirements of surface defects.

37 citations

Journal ArticleDOI
TL;DR: The spontaneous Raman scattering cross sections of the main peaks (related to the A1 vibrational mode) in rapid and conventional grown potassium dihydrogen phosphate and deuterated crystals are measured to enable the estimation of the transverse stimulatedRaman scattering gain of these nonlinear optical materials in various configurations suitable for frequency conversion and beam control in high-power, large-aperture laser systems.
Abstract: The spontaneous Raman scattering cross sections of the main peaks (related to the A1 vibrational mode) in rapid and conventional grown potassium dihydrogen phosphate and deuterated crystals are measured at 532 nm, 355 nm, and 266 nm. The measurement involves the use of the Raman line of water centered at 3400 cm-1 as a reference to obtain relative values of the cross sections which are subsequently normalized against the known absolute value for water as a function of excitation wavelength. This measurement enables the estimation of the transverse stimulated Raman scattering gain of these nonlinear optical materials in various configurations suitable for frequency conversion and beam control in high-power, large-aperture laser systems.

32 citations