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EUV mask surface cleaning effects on lithography process performance (open access)

EUV mask surface cleaning effects on lithography process performance

The reflective, multilayer based, mask architectures for extreme ultraviolet (EUV) lithography are highly susceptible to surface oxidation and contamination. As a result, EUV masks are expected to undergo cleaning processes in order to maintain the lifetimes necessary for high volume manufacturing. For this study, the impact of repetitive cleaning of EUV masks on imaging performance was evaluated. Two, high quality industry standard, EUV masks are used for this study with one of the masks undergoing repeated cleaning and the other one kept as a reference. Lithographic performance, in terms of process window analysis and line edge roughness, was monitored after every two cleans and compared to the reference mask performance. After 8x clean, minimal degradation is observed. The cleaning cycles will be continued until significant loss imaging fidelity is found.
Date: June 18, 2010
Creator: George, Simi; Baclea-an, Lorie Mae; Naulleau, Patrick; Chen, Robert J. & Liang, Ted
System: The UNT Digital Library
An Analysis of the NEXAFS Spectra of a molecular crystal: alpha-Glycine (open access)

An Analysis of the NEXAFS Spectra of a molecular crystal: alpha-Glycine

The nitrogen K-edge Near Edge X-ray Absorption Fine Structure (NEXAFS) spectrum of alpha-crystalline glycine has been calculated for temperatures ranging from 0 K to 450 K. Significant temperature dependent spectral changes are predicted. The calculated room temperature spectrum is in good agreement with experiment. At high temperatures, molecular motions strongly influence the spectrum, as any unique spectrum from an individual instantaneous configuration does not resemble the experimental result or the average calculated spectrum; complex coupled motions in this prototypical molecular crystal underlie the observed spectral changes.
Date: June 18, 2010
Creator: Schwartz, Craig P.; Saykally, Richard J. & Prendergast, David
System: The UNT Digital Library
Multiplicity behavior of $pi$$sup -$p $Yields$ pX: a multiperipheral model description (open access)

Multiplicity behavior of $pi$$sup -$p $Yields$ pX: a multiperipheral model description

None
Date: June 18, 1974
Creator: Chan, C.F. & Winkelmann, F.C.
System: The UNT Digital Library
On analog simulation of ionization cooling of muons (open access)

On analog simulation of ionization cooling of muons

Analog simulation, proposed here as an alternative approach for the study of ionization cooling of muons, is a scaled cooling experiment, using protons instead of muons as simulation particles. It is intended to be an effective and flexible, quick and inexpensive experiment for the understanding and validation of unprecedentedly complicated cooling physics, for the demonstration and optimization of various elaborated techniques for beam manipulation in 6D phase space. It can be done and perhaps should be done before the costly and time-consuming development of extremely challenging, muon-specific cooling technology. In a nutshell, the idea here is to build a toy machine in a playground of ideas, before staking the Imperial Guard of Napoleon into the bloody battlefield of Waterloo.
Date: June 18, 2001
Creator: Xie, Ming
System: The UNT Digital Library
B Physics at CDF (open access)

B Physics at CDF

Due to the large b{bar b} cross section at 1.96 TeV p - {bar p} collisions, the Tevatron is currently the most copious source of B hadrons. Recent detector upgrades for Run II have made these more accessible, allowing for a wide range of B and C/P physics with B hadrons of all flavours. In this paper we present B-physics results, and, using the versatile hadronic Two Track Trigger, a search for {Xi}(1860), from up to 240 pb{sup -1} of data.
Date: June 18, 2004
Creator: Rademacker, J.
System: The UNT Digital Library
Life history and habitat associations of the broad wood cockroach, Parcoblatta lata (Blattaria: Blattellidae) and other native cockroaches in the Coastal Plain of South Carolina. (open access)

Life history and habitat associations of the broad wood cockroach, Parcoblatta lata (Blattaria: Blattellidae) and other native cockroaches in the Coastal Plain of South Carolina.

Wood cockroaches are an important prey of the red-cockaded woodpecker, Picoides borealis, an endangered species inhabiting pine forests in the southern United States. These woodpeckers forage on the boles of live pine trees, but their prey consists of a high proportion of wood cockroaches, Parcoblatta spp., that are more commonly associated with dead plant material. Cockroach population density samples were conducted on live pine trees, dead snags and coarse woody debris on the ground. The studies showed that snags and logs are also important habitats of wood cockroaches in pine forests.
Date: June 18, 2002
Creator: Horn, Scott & Hanula, James, L.
System: The UNT Digital Library
Solvent extraction in the treatment of acidic high-level liquid waste : where do we stand? (open access)

Solvent extraction in the treatment of acidic high-level liquid waste : where do we stand?

During the last 15 years, a number of solvent extraction/recovery processes have been developed for the removal of the transuranic elements, {sup 90}Sr and {sup 137}Cs from acidic high-level liquid waste. These processes are based on the use of a variety of both acidic and neutral extractants. This chapter will present an overview and analysis of the various extractants and flowsheets developed to treat acidic high-level liquid waste streams. The advantages and disadvantages of each extractant along with comparisons of the individual systems are discussed.
Date: June 18, 1998
Creator: Horwitz, E. P. & Schulz, W. W.
System: The UNT Digital Library
Combustion of TNT products in a confined explosion (open access)

Combustion of TNT products in a confined explosion

The effects of turbulent combustion of detonation products gases in a confined explosion are explored via laboratory experiments and high-resolution numerical simulations. The expanded products from the detonation of a TNT charge are rich in C and CO, which act as a fuel. When these hot gases mix with air, they are oxidized to CO2--thereby releasing 2482 Cal/g in addition to the 1093 Cal/g deposited by the detonation wave. In this case, the exothermic power is controlled by the turbulent mixing rate, rather than by chemistry. A kinetic law of turbulent combustion is suggested for this process. Pressure histories from the numerical simulations were in good agreement with the experimental measurements--demonstrating that the numerical model contains the fundamental mechanism that controls the exothermic process.
Date: June 18, 1999
Creator: Ferguson, R E; Kuhl, A L & Oppenheim, A K
System: The UNT Digital Library
Plasma inverse transition acceleration (open access)

Plasma inverse transition acceleration

It can be proved fundamentally from the reciprocity theorem with which the electromagnetism is endowed that corresponding to each spontaneous process of radiation by a charged particle there is an inverse process which defines a unique acceleration mechanism, from Cherenkov radiation to inverse Cherenkov acceleration (ICA) [1], from Smith-Purcell radiation to inverse Smith-Purcell acceleration (ISPA) [2], and from undulator radiation to inverse undulator acceleration (IUA) [3]. There is no exception. Yet, for nearly 30 years after each of the aforementioned inverse processes has been clarified for laser acceleration, inverse transition acceleration (ITA), despite speculation [4], has remained the least understood, and above all, no practical implementation of ITA has been found, until now. Unlike all its counterparts in which phase synchronism is established one way or the other such that a particle can continuously gain energy from an acceleration wave, the ITA to be discussed here, termed plasma inverse transition acceleration (PITA), operates under fundamentally different principle. As a result, the discovery of PITA has been delayed for decades, waiting for a conceptual breakthrough in accelerator physics: the principle of alternating gradient acceleration [5, 6, 7, 8, 9, 10]. In fact, PITA was invented [7, 8] as one of several …
Date: June 18, 2001
Creator: Xie, Ming
System: The UNT Digital Library
Preparing emergency response teams for effective risk communications. (open access)

Preparing emergency response teams for effective risk communications.

None
Date: June 18, 2002
Creator: Ingle, K.
System: The UNT Digital Library
U.S.A. visibility monitoring, trends, and regulatory programs and their relevance to Korea. (open access)

U.S.A. visibility monitoring, trends, and regulatory programs and their relevance to Korea.

This paper describes visibility monitoring and regulatory programs in the United States, particularly within certain designated National Parks and Wilderness Areas. Government agencies responsible for the management of federal lands, in cooperation with other federal, state, and regional air quality organizations, have established a monitoring program of more than 125 sites. Recent visual documentation (scene images), optical measurements, and aerosol characterizations (mass and chemical speciation) obtained at selected monitoring sites are presented, as information on general spatial and temporal visibility trends. National regulations are described that limit the amount of additional visibility impairment from new or modified emission sources and that establish a schedule for improving existing conditions in designated areas. The relevance of the experience in developing and implementing these programs to the planning for programs to address emerging visibility problems in Korea is discussed.
Date: June 18, 2002
Creator: Archer, S. F. & Chun, K. C.
System: The UNT Digital Library
Generation of attosecond electron bunches (open access)

Generation of attosecond electron bunches

Ultra-fast science is an important new research frontier that is driving the development of novel sources for generation of extremely short x-ray and electron pulses. Recent advances in femtosecond lasers have stimulated development of femtosecond x-ray sources that allow the study of matter at the time scale shorter than period of oscillations of atoms in molecules, {approx} 100 fs. The next breakthrough would be a source of electron pulses comparable with atomic periods {omega}{sup -1} {approx} 100 attosecond (10{sup -16} s), where {omega} is a transition frequency between atomic levels. This will open qualitatively new class of phenomena based on the interaction of atomic electrons in the medium with a collective electric field of electron pulses and not with their individual electrons. For example, one can expect coherent ionization losses that are proportional to a square number of electrons in the microbunch, phase synchronized excitation of medium followed by its relaxation with a radiation of a single-cycled optical pulse, excitation of entanglement states in the medium of atoms with few valence electrons, and possibly other new phenomena, yet to be identified. Simple estimation of coherent ionization losses shows that a 100 MeV, 100 attosecond electron pulse containing 10{sup 5} electrons …
Date: June 18, 2001
Creator: Zholents, Alexander A.; Zolotorev, Max S. & Wan, Weishi
System: The UNT Digital Library
RAPID MAPPING TOOL: AN ARCMAP EXTENSION (open access)

RAPID MAPPING TOOL: AN ARCMAP EXTENSION

Cartographic production laboratories produce large volumes of maps for diverse customers. Turnaround time and consistency are key concerns. The Rapid Mapping Tool is an ArcMap based tool that enables rapid creation of maps to meet customer needs. This tool was constructed using VB/VBA, ArcObjects, and ArcGIS templates. The core capability of ArcMap is extended for custom map production by storing specifications associated with a map or template in a companion XML document. These specifications include settings and preferences used to create custom maps. The tool was developed as a component of an enterprise GIS, which enables spatial data management and delivery using ArcSDE, ArcIMS, Oracle, and a web-based request tracking system.
Date: June 18, 2002
Creator: LINGER, STEVE P.; RICH, PAUL M.; WALTHER, DOUG; WITKOWSKI, MARC S.; JONES, MARCIA A. & KHALSA, HARI S.
System: The UNT Digital Library
Fundamental limits on beam stability at the Advanced Photon Source. (open access)

Fundamental limits on beam stability at the Advanced Photon Source.

Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.
Date: June 18, 1998
Creator: Decker, G. A.
System: The UNT Digital Library
Vibratory response modeling and verification of a high precision optical positioning system. (open access)

Vibratory response modeling and verification of a high precision optical positioning system.

A generic vibratory-response modeling program has been developed as a tool for designing high-precision optical positioning systems. Based on multibody dynamics theory, the system is modeled as rigid-body structures connected by linear elastic elements, such as complex actuators and bearings. The full dynamic properties of each element are determined experimentally or theoretically, then integrated into the program as inertial and stiffness matrices. Utilizing this program, the theoretical and experimental verification of the vibratory behavior of a double-multilayer monochromator support and positioning system is presented. Results of parametric design studies that investigate the influence of support floor dynamics and highlight important design issues are also presented. Overall, good matches between theory and experiment demonstrate the effectiveness of the program as a dynamic modeling tool.
Date: June 18, 1999
Creator: Barraza, J.; Kuzay, T.; Royston, T. J. & Shu, D.
System: The UNT Digital Library
Problems of the laser-augmented pinch proposal (open access)

Problems of the laser-augmented pinch proposal

None
Date: June 18, 1973
Creator: Shearer, J.W.
System: The UNT Digital Library
Optical Interferometry Diagnostics in Laser-Driven Equation of State Experiments (open access)

Optical Interferometry Diagnostics in Laser-Driven Equation of State Experiments

We have developed and tested several optical interferometric diagnostics to measure preheat and shock velocity in high-pressure equation of state experiments on the Nova laser. Theory and practical application of interferometric measurement techniques with illustrative experimental results are presented.
Date: June 18, 1999
Creator: Cauble, R. C.; Celliers, P. M.; Collins, G. W.; Da Silva, L. B.; Gold, D. M.; Kalantar, D. H. et al.
System: The UNT Digital Library
X-ray Emissivities from Well Characterized Underdense, Laser-Heated Gas Targets (open access)

X-ray Emissivities from Well Characterized Underdense, Laser-Heated Gas Targets

Maximizing the conversion efficiency (CE) of laser energy into multi-keV x-rays is a general concern to many areas of high-energy-density plasma physics. Bright x-ray sources are needed for backlighters in order to radiograph targets in inertial-confinement fusion (ICF) experiments. As the targets get larger, and as compression in the targets increases, the backlighter sources need to be brighter and the backlighter-photon energies must increase. To this end, for a given laser power, backlighters can become brighter by becoming more efficient at converting the drive beams to multi-keV x-rays. Volumetric heating of low-density gas targets has been shown to be a very efficient method of producing x-rays. Recently, laser heating of an underdense aerogel target has demonstrated efficient x-ray production. Ongoing experiments are optimizing these designs; this paper reports on detailed calculations of the x-ray yield from L-shell Kr in laser-heated targets.
Date: June 18, 2004
Creator: Fournier, K. B.; Back, C. A.; Constantin, C.; Miller, M. C.; Suter, L. J. & Chung, H.
System: The UNT Digital Library
ITER pellet fueling (open access)

ITER pellet fueling

This paper discusses: ITER fueling issues; ITER pellet sizes, ablation and penetration; and ITER pellet injector requirements. 5 refs., 6 figs.
Date: June 18, 1988
Creator: Houlberg, W.A.
System: The UNT Digital Library
Large-Eddy Simulation and Multigrid Methods (open access)

Large-Eddy Simulation and Multigrid Methods

A method to simulate turbulent flows with Large-Eddy Simulation on unstructured grids is presented. Two kinds of dynamic models are used to model the unresolved scales of motion and are compared with each other on different grids. Thereby the behavior of the models is shown and additionally the feature of adaptive grid refinement is investigated. Furthermore the parallelization aspect is addressed.
Date: June 18, 2001
Creator: Falgout,R D; Naegle,S & Wittum,G
System: The UNT Digital Library
Measurement of the Relative Intensity of the Ly-(alpha) Lines in Fe 25+ (open access)

Measurement of the Relative Intensity of the Ly-(alpha) Lines in Fe 25+

The intensity of the polarized Ly-{alpha}{sub 1} (2p{sub 3/2} {yields} 1s{sub 1/2}) transition has been measured relative to that of the unpolarized Ly-{alpha}{sub 2} (2p{sub 1/2} {yields} 1s{sub 1/2}) transition in Fe{sup 25+}. The measurements were made with the Livermore electron beam ion trap EBIT-II for beam energies from threshold to 2.5 times threshold. The results are compared to the corresponding intensity ratio predicted using excitation cross sections from distorted-wave calculations, which includes polarization, the M1(2s{sub 1/2} {yields} 1s{sub 1/2}) transition, and cascade contributions. Discrepancies are found that tend to confirm a recent report of a measurement of the Ly-{alpha} lines in Ti{sup 21+} performed on the Tokyo electron beam ion trap.
Date: June 18, 2002
Creator: Wong, K. L.; Beiersdorfer, P.; Reed, K. J. & Osterheld, A. L.
System: The UNT Digital Library
The Effective Field Theory of Multifield Inflation (open access)

The Effective Field Theory of Multifield Inflation

None
Date: June 18, 2013
Creator: Senatore, Leonardo; /Princeton, Inst. Advanced Study /Stanford U., Phys. Dept. /KIPAC, Menlo Park; Zaldarriaga, Matias & /Princeton, Inst. Advanced Study
System: The UNT Digital Library
Fermi-LAT Study of Gamma-Ray Emission in the Direction of Supernova Remnant W49B (open access)

Fermi-LAT Study of Gamma-Ray Emission in the Direction of Supernova Remnant W49B

None
Date: June 18, 2013
Creator: Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G. et al.
System: The UNT Digital Library
Cascades with Adjoint Matter: Adjoint Transitions (open access)

Cascades with Adjoint Matter: Adjoint Transitions

None
Date: June 18, 2013
Creator: Simic, Dusan
System: The UNT Digital Library