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Corrosion-resistant multilayer coatings for the 28-75 nm wavelength region

Description: Corrosion has prevented use of SiC/Mg multilayers in applications requiring good lifetime stability. We have developed Al-based barrier layers that dramatically reduce corrosion, while preserving high reflectance and low stress. The aforementioned advances may enable the implementation of corrosion-resistant, high-performance SiC/Mg coatings in the 28-75 nm region in applications such as tabletop EUV/soft x-ray laser sources and solar physics telescopes. Further study and optimization of corros… more
Date: November 8, 2011
Creator: Soufli, R.; Fernandez-Perea, Monica & Al, E. T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Raman Spectroscopy of UH3 from the Hydrogen Corrosion of Uranium

Description: Hydrogen reacts with a uranium surface to form a fine, pyrophoric metal power (UH{sub 3}). Few spectroscopic studies have been conducted to study this reaction. Advances in Raman spectroscopy permit the application of the Raman method to formally difficult areas of chemistry such as the hydrogen corrosion of uranium: availability of multiple laser excitation wavelengths; fiber optics delivery and collection systems; upgraded instrumentation and detection techniques; and development of special e… more
Date: May 31, 2011
Creator: Smyrl, N. R.; Stowe, A. C. & Powell, G. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Femtosecond spectroscopy with vacuum ultraviolet pulse pairs

Description: We combine different wavelengths from an intense high-order harmonics source with variable delay at the focus of a split-mirror interferometer to conduct pump-probe experiments on gas-phase molecules. We report measurements of the time resolution (< 44fs) and spatial profiles (4 {micro}m x 12 {micro}m) at the focus of the apparatus. We demonstrate the utility of this two-color, high-order-harmonic technique by time resolving molecular hydrogen elimination from C{sub 2} H{sub 4} excited into … more
Date: June 17, 2011
Creator: Allison, Tom; Wright, Travis; Stooke, Adam; Khurmi, Champak; van Tilborg, Jeroen; Liu, Yanwei et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Multifilter Rotating Shadowband Radiometer (MFRSR) Handbook

Description: The visible Multifilter Rotating Shadowband Radiometer (MFRSR) is a passive instrument that measures global and diffuse components of solar irradiance at six narrowband channels and one open, or broadband, channel (Harrison et al. 1994). Direct irradiance is not a primary measurement, but is calculated using the diffuse and global measurements. To collect one data record, the MFRSR takes measurements at four different shadowband positions. The first measurement is taken with the shadowband in t… more
Date: February 7, 2011
Creator: Hodges, G. B. & Michalsky, J. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Optimization for Single-Spike X-Ray FELs at LCLS with a Low Charge Beam

Description: The Linac Coherent Light Source is an x-ray free-electron laser at the SLAC National Accelerator Laboratory, which is operating at x-ray wavelengths of 20-1.2 Angstrom with peak brightness nearly ten orders of magnitude beyond conventional synchrotron radiation sources. At the low charge operation mode (20 pC), the x-ray pulse length can be <10 fs. In this paper we report our numerical optimization and simulations to produce even shorter x-ray pulses by optimizing the machine and undulator s… more
Date: December 14, 2011
Creator: Wang, L.; Ding, Y. & Huang, Z.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

Description: An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either eleva… more
Date: March 14, 2011
Creator: Clark, E.; Kane, M. & Jiang, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

Description: We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical s… more
Date: December 1, 2011
Creator: Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Absorber height effects on SWA restrictions and 'Shadow' LER

Description: As extreme-ultraviolet lithography (EUVL) approaches introduction at the 22-nm half-pitch node, several key aspects of absorber height effects remain unexplored. In particular, sidewall angle (SWA) restrictions based on the height of the mask absorber has not yet been clearly defined. In addition, the effects of absorber height on line-edge roughness (LER) from shadowing has not been examined. We make an initial investigation into how tight SWA constraints are and the extent to which shadow LER… more
Date: February 21, 2011
Creator: McClinton, Brittany & Naulleau, Patrick
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Status of the Linac Coherent Light Source

Description: The Linac Coherent Light Source (LCLS) is a free electron laser facility in construction at Stanford Linear Accelerator Center. It is designed to operate in the wavelength range 0.15-1.5 nanometers. At the time of this conference, civil construction of new tunnels and buildings is complete, the necessary modifications to the SLAC linac are complete, and the undulator system and x-ray optics/diagnostics are being installed. The electron gun, 135 MeV injector linac and 250 MeV bunch compressor we… more
Date: November 4, 2011
Creator: Galayda, John N.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Beam Dynamics Study of X-Band Linac Driven X-Ray FELS

Description: Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described b… more
Date: December 13, 2011
Creator: Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T. O.; Wu, J. & Sun, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Raman Spectroscopy of Lithium Hydride Corrosion: Selection of an Appropriate Excitation Wavelength to Minimize Fluorescence

Description: The recent interest in a hydrogen-based fuel economy has renewed research into metal hydride chemistry. Many of these compounds react readily with water to release hydrogen gas and form a caustic. Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFT) has been used to study the hydrolysis reaction. The LiOH stretch appears at 3670 cm{sup -1}. Raman spectroscopy is a complementary technique that employs monochromatic excitation (laser) allowing access to the low energy region of the… more
Date: May 26, 2011
Creator: Stowe, A. C. & Smyrl, N. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design of the fundamental power coupler and photocathode inserts for the 112MHz superconducting electron gun

Description: A 112 MHz superconducting quarter-wave resonator electron gun will be used as the injector of the Coherent Electron Cooling (CEC) proof-of-principle experiment at BNL. Furthermore, this electron gun can be the testing cavity for various photocathodes. In this paper, we present the design of the cathode stalks and a Fundamental Power Coupler (FPC) designated to the future experiments. Two types of cathode stalks are discussed. Special shape of the stalk is applied in order to minimize the RF pow… more
Date: July 25, 2011
Creator: Xin, T.; Ben-Zvi, Ilan; Belomestnykh, S.; Chang, X.; Rao, T.; Skaritka, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Mask roughness induced LER control and mitigation: aberrations sensitivity study and alternate illumination scheme

Description: Here we conduct a mask-roughness-induced line-edge-roughness (LER) aberrations sensitivity study both as a random distribution amongst the first 16 Fringe Zernikes (for overall aberration levels of 0.25, 0.50, and 0.75nm rms) as well as an individual aberrations sensitivity matrix over the first 37 Fringe Zernikes. Full 2D aerial image modeling for an imaging system with NA = 0.32 was done for both the 22-nm and 16-nm half-pitch nodes on a rough mask with a replicated surface roughness (RSR) of… more
Date: March 11, 2011
Creator: McClinton, Brittany M. & Naulleau, Patrick P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Selective Photothermolysis to target Sebaceous Glands: Theoretical Estimation of Parameters and Preliminary Results Using a Free Electron Laser

Description: The success of permanent laser hair removal suggests that selective photothermolysis (SP) of sebaceous glands, another part of hair follicles, may also have merit. About 30% of sebum consists of fats with copious CH2 bond content. SP was studied in vitro, using free electron laser (FEL) pulses at an infrared CH2 vibrational absorption wavelength band. Absorption spectra of natural and artificially prepared sebum were measured from 200 nm to 3000 nm, to determine wavelengths potentially able to … more
Date: December 1, 2011
Creator: Fernanda Sakamoto, Apostolos Doukas, William Farinelli, Zeina Tannous, Michelle D. Shinn, Stephen Benson, Gwyn P. Williams, H. Dylla, Richard Anderson
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design and first cold test of BNL superconducting 112 MHz QWR for electron gun applications

Description: Brookhaven National Laboratory and Niowave, Inc. have designed, fabricated, and performed the first cold test of a superconducting 112 MHz quarter-wave resonator (QWR) for electron gun experiments. The first cold test of the QWR cryomodule has been completed at Niowave. The paper discusses the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule for future experiments. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was propose… more
Date: March 28, 2011
Creator: Belomestnykh, S.; Ben-Zvi, Ilan; Boulware, C. H.; Chang, X.; Grimm, T. L.; Siegel, B. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Photoionizing Trapped Highly Charged Ions with Synchrotron Radiation

Description: Photoabsorption by highly charged ions plays an essential role in astrophysical plasmas. Diagnostics of photoionized plasmas surrounding binary systems rely heavily on precise identification of absorption lines and on the knowledge of their cross sections and widths. Novel experiments using an electron beam ion trap, FLASH EBIT, in combination with monochromatic synchrotron radiation allow us to investigate ions in charge states hitherto out of reach. Trapped ions can be prepared in any charge … more
Date: September 12, 2011
Creator: Crespo, J. R.; Simon, M.; Beilmann, C.; Rudolph, J.; Steinbruegge, R.; Eberle, S. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effects of Inclusions in HSLA Carbon Steel on Pitting Corrosion in CaCl2

Description: Susceptibility of high strength low alloy steel to localized corrosion was studied in 6.7 M CaCl{sub 2} for oil and natural gas drilling applications. Results of the immersion and electrochemical experiments showed that the steel is susceptible to pitting corrosion. Optical microscopy investigations of the polished samples revealed that 10% of the surface area was occupied by defects in the form of pits. The energy dispersive X-ray (EDX) and wavelength dispersive X-ray (WDX) chemical analyses r… more
Date: December 5, 2011
Creator: Ziomek-Moroz, M.; Bullard, S.; Rozman, K. & Kruzic, J.J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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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

Ultra-Short Electron Bunch and X-Ray Temporal Diagnostics with an X-Band Transverse Deflector

Description: The measurement of ultra-short electron bunches on the femtosecond time scale constitutes a very challenging problem. In X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS), generation of sub-ten femtosecond X-ray pulses is possible, and some efforts have been put into both ultra-short electron and X-ray beam diagnostics. Here we propose a single-shot method using a transverse rf deflector (X-band) after the undulator to reconstruct both the electron bunch and X-… more
Date: December 13, 2011
Creator: Ding, Y.; Emma, P.; Frisch, J.; Huang, Z.; Loos, H.; Krejcik, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A New Type of Plasma Wakefield Accelerator Driven By Magnetowaves

Description: We present a new concept for a plasma wakefield accelerator driven by magnetowaves (MPWA). This concept was originally proposed as a viable mechanism for the 'cosmic accelerator' that would accelerate cosmic particles to ultra-high energies in the astrophysical setting. Unlike the more familiar plasma wakefield accelerator (PWFA) and the laser wakefield accelerator (LWFA) where the drivers, the charged-particle beam and the laser, are independently existing entities, MPWA invokes the high-frequ… more
Date: September 12, 2011
Creator: Chen, Pisin; Chang, Feng-Yin; Lin, Guey-Lin; Noble, Robert J. & Sydora, Richard
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Variable Gap Undulator for 1.5-48 Kev Free Electron Laser at Linac Coherent Light Source

Description: We study the feasibility of generating femtosecond duration Free-Electron Laser with a variable photon energy from 1.5 to 48 keV, using an electron bunch with the same characteristics of the LINAC Coherent Light Source (LCLS) bunch, and a planar undulator with additional focusing. We assume that the electron bunch energy can be changed, and the undulator has a variable gap, allowing a variable undulator parameter. It is assumed to be operated in an ultra-low charge and ultra-short pulse regime.… more
Date: August 17, 2011
Creator: Pellegrini, C. & Wu, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Optics-free x-ray FEL oscillator

Description: There is a need for an Optics-Free FEL Oscillators (OFFELO) to further the advantages of free-electron lasers and turning them in fully coherent light sources. While SASE (Self-Amplified Spontaneous Emission) FELs demonstrated the capability of providing very high gain and short pulses of radiation and scalability to the X-ray range, the spectra of SASE FELs remains rather wide ({approx}0.5%-1%) compared with typical short wavelengths FEL-oscillators (0.01%-0.0003% in OK-4 FEL). Absence of good… more
Date: March 28, 2011
Creator: Litvinenko, V. N.; Hao, Y.; Kayran, D. & Trbojevic, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Superconducting 112 MHz QWR electron gun

Description: Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk option… more
Date: July 25, 2011
Creator: Belomestnykh, S.; Ben-Zvi, Ilan; Boulware, C. H.; Chang, X.; Grimm, T. L.; Rao, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A1.5 Fusion Performance

Description: Analysis and radiation hydrodynamics simulations for expected high-gain fusion target performance on a demonstration 1-GWe Laser Inertial Fusion Energy (LIFE) power plant in the mid-2030s timeframe are presented. The required laser energy driver is 2.2 MJ at a 0.351-{micro}m wavelength, and a fusion target gain greater than 60 at a repetition rate of 16 Hz is the design goal for economic and commercial attractiveness. A scaling-law analysis is developed to benchmark the design parameter space f… more
Date: March 31, 2011
Creator: Amendt, P
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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