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Actinic EUV mask inspection beyond 0.25 NA

Description: Operating at EUV wavelengths, the SEMATECH Berkeley Actinic Inspection Tool (AIT) is a zoneplate microscope that provides high quality aerial image measurements in routine operations for SEMATECH member companies. We have upgraded the optical performance of the AIT to provide multiple image magnifications, and several inspection NA values up to 0.35 NA equivalent (0.0875 mask-side). We report on the improved imaging capabilities including resolution below 100-nm on the mask side (25 nm, 4x wafe… more
Date: August 6, 2008
Creator: Goldberg, Kenneth A.; Mochi, Iacopo; Anderson, Erik H.; Rekawa, Seno B.; Kemp, Charles D.; Huh, S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Proof-of-Principle Echo-enabled Harmonic Generation Free Electron Laser Experiment at SLAC

Description: With the advent of X-ray Free Electron Lasers (FELs), new methods have been developed to extend capabilities at short wavelengths beyond Self-Amplified Spontaneous Emission (SASE). In particular, seeding of a FEL allows for temporal control of the radiation pulse and increases the peak brightness by orders of magnitude. Most recently, Gennady Stupakov and colleagues at SLAC proposed a new technique: Echo-Enabled Harmonic Generation (EEHG). Here a laser microbunches the beam in an undulator and … more
Date: January 6, 2012
Creator: Pernet, Pierre-Louis
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

The Effect of an Oxide Layer on Resistive-Wall Wakefields

Description: Shorter and shorter electron bunches are now used in the FEL designs. The fine structure of the wall of a beam vacuum pipe plays more noticeable role in the wake field generation. Additionally to the resistance and roughness, the wall may have an oxide layer, which is usually a dielectric. It is important for aluminium pipe, which have Al2O3 layer. The thickness of this layer may vary in a large range: 1-100 nm. We study this effect for the very short (20-1000 nm) ultra relativistic bunches in … more
Date: July 6, 2009
Creator: Novokhatski, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Microstructure and Mechanical Instability of Water-Quenched U-6wt% Nb Alloy Affected by Long-Term Aging

Description: A combinative approach of microhardness testing, tensile testing, and TEM microstructural analysis was employed to study the microstructure and mechanical instability of a water-quenched U-6wt.% Nb (WQ-U6Nb) alloy subjected to different aging schedules including artificial aging at 200 C, 15-year natural aging at ambient temperatures, and 15-year natural aging followed by accelerative aging at 200 C. The changes in mechanical property during and after the aging processes were examined using mic… more
Date: December 6, 2005
Creator: Hsiung, L & Zhou, J
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Influence of the Sb dopant distribution on far infrared photoconductivity in Ge:Sb blocked impurity band detectors

Description: Extended long wavelength response to {approx}200 {micro}m (50 cm{sup -1}) has been observed in Ge:Sb Blocked Impurity Band (BIB) detectors with N{sub D} {approx} 1 x 10{sup 16} cm{sup -3}. The cut-off wavelength increases from 150 {micro}m (65 cm{sup -1}) to 200 {micro}m (50 cm{sup -1}) with increasing bias. The responsivity at long wavelengths was lower than expected. This can be explained by considering the observed Sb diffusion profile in a transition region between the blocking layer and ac… more
Date: February 6, 2002
Creator: Bandaru, Jordana; Beeman, Jeffrey W.; Haller, Eugene E.; Samperi, Stacy & Haegel, Nancy M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

AnisWave2D: User's Guide to the 2d Anisotropic Finite-DifferenceCode

Description: This document describes a parallel finite-difference code for modeling wave propagation in 2D, fully anisotropic materials. The code utilizes a mesh refinement scheme to improve computational efficiency. Mesh refinement allows the grid spacing to be tailored to the velocity model, so that fine grid spacing can be used in low velocity zones where the seismic wavelength is short, and coarse grid spacing can be used in zones with higher material velocities. Over-sampling of the seismic wavefield i… more
Date: January 6, 2005
Creator: Toomey, Aoife
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nova Experiments Examining Raleigh-Taylor Instability in Materials with Strength

Description: Material strength can affect the growth of the Rayleigh-Taylor instability in solid materials, where growth occurs through plastic flow. In order to study this effect at megabar pressures, we have shocked metal foils using hohlraum x-ray drive on Nova, and observed the growth of pre-imposed modulations with x-ray radiography. Previous experiments employing Cu foils did not conclusively show strength effects for resolvable wavelengths. Therefore, we have redesigned the experiment to use aluminum… more
Date: October 6, 1999
Creator: Weber, S. V.; Kalantar, D. H.; Colvin, J. D.; Gold, D. M.; Mikaelian, K. O.; Remington, B. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Developing solid state experiments on the Nova laser

Description: An x-ray drive has been developed to shock compress metal foils in the solid state using an internally shielded hohlraum with a high contrast shaped pulse from the Nova laser. The drive has been characterized and hydrodynamics experiments designed to study growth of the Rayleigh-Taylor (RT) instability in Cu foils at 3 Mbar peak pressures in the plastic flow regime have been started. Pre-imposed modulations with an initial wavelength of 20-50 {micro}m, and amplitudes of 1.0-2.5 {micro}m show gr… more
Date: August 6, 1999
Creator: Chandler, E. A.; Colvin, J. D.; Failor, B. H.; Gold, D. M.; Hauer, A.; Kalantar, D. H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Quantifying Uranium Isotope Ratios Using Resonance Ionization Mass Spectrometry: The Influence of Laser Parameters on Relative Ionization Probability

Description: Resonance Ionization Mass Spectrometry (RIMS) has been developed as a method to measure relative uranium isotope abundances. In this approach, RIMS is used as an element-selective ionization process to provide a distinction between uranium atoms and potential isobars without the aid of chemical purification and separation. We explore the laser parameters critical to the ionization process and their effects on the measured isotope ratio. Specifically, the use of broad bandwidth lasers with autom… more
Date: September 6, 2011
Creator: Isselhardt, B H
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Emission line spectra of S VII ? S XIV in the 20 ? 75 ? wavelength region

Description: As part of a larger project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, the authors present observations of sulfur lines in the soft X-ray and extreme ultraviolet regions. The database includes wavelength measurements with standard errors, relative intensities, and line assignments for 127 transitions of S VII through S XIV between 20 and… more
Date: August 6, 2004
Creator: Lepson, J K; Beiersdorfer, P; Behar, E & Kahn, S M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

High Resolution Absorption Spectroscopy using Externally Dispersed Interferometry

Description: We describe the use of Externally Dispersed Interferometry (EDI) for high-resolution absorption spectroscopy. By adding a small fixed-delay interferometer to a dispersive spectrograph, a precise fiducial grid in wavelength is created over the entire spectrograph bandwidth. The fiducial grid interacts with narrow spectral features in the input spectrum to create a moire pattern. EDI uses the moire pattern to obtain new information about the spectra that is otherwise unavailable, thereby improvin… more
Date: July 6, 2005
Creator: Edelstein, J & Erskine, D J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

LUX - A design study for a linac/laser-based ultrafast X-ray source

Description: A warm, relativistic fluid theory of a nonequilibrium, collisionless plasma is developed to analyze nonlinear plasma waves excited by intense drive beams. The maximum amplitude and wavelength are calculated for nonrelativistic plasma temperatures and arbitrary plasma wave phase velocities. The maximum amplitude is shown to increase in the presence of a laser field. These results set a limit to the achievable gradient in plasma-based accelerators.
Date: August 6, 2004
Creator: Corlett, J. N.; Barletta, W. A.; DeSantis, S.; Doolittle, L.; Fawley, W. M.; Heimann, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Progress report of FY 1998 activities: Continued development of an integrated sounding system in support of the DOE/ARM experimental program

Description: Both during September 15-30, 1996 and September 15-October 5, 1997, the Environmental Technology Laboratory (ETL) participated in an experiment at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site that was designed to study many of the ways that ARM is measuring water vapor. These experiments, called the Water Vapor Intensive Operating Periods (WVIOPs), produced some results of significant importance to ARM water vapor measurements. We have spent the major portion of this … more
Date: September 6, 1998
Creator: Westwater, Edgeworth R.; Han, Yong & Leuskiy, Vladimir
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

NIF optical specifications - the importance of the RMS gradient specification

Description: The performance of the National Ignition Facility (NIF), especially in terms of laser focusability, will be determined by several key factors. One of these key factors is the optical specification for the thousands of large aperture optics that will comprise the 192 beamlines. We have previously reported on the importance of the specification of the power spectral density (PSD) on NIF performance. Recently, we have been studying the importance of long spatial wavelength (>33 mm) phase errors… more
Date: July 6, 1998
Creator: Auerbach, J. M.; Cotton, C. T.; English, R. E.; Henesian, M. A.; T, Hunt J.; Kelly, J. H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Practical Approach to Monochromatic Lwfa.

Description: Dependence of the LWFA performance upon the laser wavelength is applied to optimization of the plasma-channeled standard LWFA operating in a linear regime. Electron beam energy spread, emittance and luminosity depend upon the proportion of the electron bunch size to the plasma wavelength. This proportion tends to improve with the laser wavelength increase. We propose the two-stage {approximately}1 GeV LWFA with the controlled energy spread and emittance based on realistic capabilities of the BN… more
Date: July 6, 1998
Creator: Pogorelsky, I. V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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