Tunable lasers in isotope separation, a colorful view of a dye chemist (open access)

Tunable lasers in isotope separation, a colorful view of a dye chemist

Some of the problems to be encountered in the large-scale use of dye lasers in an isotope separation plant are discussed. Why should dye lasers be employed. How can dye conversion efficiency be optimized. How can dye photochemical decomposition and hence running costs be minimized and how serious is this effect anyway. What are toxicity problems with the dye. These and similar issues are examined.
Date: December 15, 1976
Creator: Hammond, P. R.
System: The UNT Digital Library
Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste (open access)

Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste

Laboratory results of a comprehensive, regulatory performance test program, utilizing an extruded bitumen and a surrogate, sodium nitrate-based waste, have been compiled at the Oak Ridge National Laboratory (ORNL). Using a 53 millimeter, Werner and Pfleiderer extruder, operated by personnel of WasteChem Corporation of Paramus, New Jersey, laboratory-scale, molded samples of type three, air blown bitumen were prepared for laboratory performance testing. A surrogate, low-level, mixed liquid waste, formulated to represent an actual on-site waste at ORNL, containing about 30 wt % sodium nitrate, in addition to eight heavy metals, cold cesium and strontium was utilized. Samples tested contained three levels of waste loading: that is, forty, fifty and sixty wt % salt. Performance test results include the ninety day ANS 16.1 leach test, with leach indices reported for all cations and anions, in addition to the EP Toxicity test, at all levels of waste loading. Additionally, test results presented also include the unconfined compressive strength and surface morphology utilizing scanning electron microscopy. Data presented include correlations between waste form loading and test results, in addition to their relationship to regulatory performance requirements.
Date: December 15, 1986
Creator: Mattus, A. J. & Kaczmarsky, M. M.
System: The UNT Digital Library
Analysis of Bulk DKDP Damage Distribution, Obscuration and Pulse Length Dependence (open access)

Analysis of Bulk DKDP Damage Distribution, Obscuration and Pulse Length Dependence

Recent LLNL experiments reported elsewhere at this conference explored the pulselength dependence of 351 nm bulk damage incidence in DKDP. The results found are consistent, in part, with a model in which a distribution of small bulk initiators is assumed to exist in the crystal and the damage threshold is determined by reaching a critical temperature. The observed pulse length dependence can be explained as being set by the most probable defect capable of causing damage at a given pulselength. Analysis of obscuration in side illuminated images of the damaged region yields estimates of the damage site distributions that are in reasonable agreement with the distributions experimentally directly estimated.
Date: December 15, 2000
Creator: Feit, M D; Rubenchik, A M & Runkel, M
System: The UNT Digital Library
Attomole quantitation of protein separations with accelerator mass spectrometry (open access)

Attomole quantitation of protein separations with accelerator mass spectrometry

Quantification of specific proteins depends on separation by chromatography or electrophoresis followed by chemical detection schemes such as staining and fluorophore adhesion. Chemical exchange of short-lived isotopes, particularly sulfur, is also prevalent despite the inconveniences of counting radioactivity. Physical methods based on isotopic and elemental analyses offer highly sensitive protein quantitation that has linear response over wide dynamic ranges and is independent of protein conformation. Accelerator mass spectrometry quantifies long-lived isotopes such as 14C to sub-attomole sensitivity. We quantified protein interactions with small molecules such as toxins, vitamins, and natural biochemicals at precisions of 1-5% . Micro-proton-induced-xray-emission quantifies elemental abundances in separated metalloprotein samples to nanogram amounts and is capable of quantifying phosphorylated loci in gels. Accelerator-based quantitation is a possible tool for quantifying the genome translation into proteome.
Date: December 15, 2000
Creator: Vogel, J. S.; Grant, P. G.; Buccholz, B. A.; Dingley, K. & Turteltaub, K. W.
System: The UNT Digital Library
Port and Harbor Security (open access)

Port and Harbor Security

Port and Harbor Security is a daunting task to which optics and photonics offers significant solutions. We are pleased to report that the 2005 Defense and Security Symposium (DSS, Orlando, FL) will include reports on active and passive photonic systems operating from both airborne and subsurface platforms. In addition to imaging techniques, there are various photonic applications, such as total internal reflection fluorescence (TIRF), which can be used to ''sniff'' for traces of explosives or contaminants in marine. These non-imaging technologies are beyond the scope of this article, but will also be represented at DSS 2005. We encourage colleagues to join our technical group to help us to make our ports and harbors safer and more secure.
Date: December 15, 2004
Creator: Saito, T.; Guthmuller, H. & DeWeert, M.
System: The UNT Digital Library
Solution Sythesis Of Geranium Nanocrystals: Success And Open Challenges (open access)

Solution Sythesis Of Geranium Nanocrystals: Success And Open Challenges

We present a two-steps synthesis route that yields nanometer size crystalline germanium in the form of a black powder. It relies on high temperature decomposition of tetraethylgermane (TEG) in organic solvents. The presence of pure germanium with diamond structure is unambiguously attested by powder XRD measurements. Low resolution TEM indicates that the particles are between {approx}5 to 30 nm in size depending on the synthesis conditions. The as-synthesized Ge powders can be stored in air for months and no oxidation occurs. The Ge powders are sparingly soluble in conventional solvents because Ge nanocrystals are likely embedded in a matrix, composed mainly of C=C, C-C, and C-H bonds. The presence of residual organic by-products impedes probing of the optical properties of the dots. Also, we discuss drawbacks and open challenges in high temperature solution synthesis of Ge nanocrystals that could also be faced in the synthesis of Si nanocrystals. Overall, our results call for a cautious interpretation of reported optical properties of Ge and Si nanocrystals obtained by high temperature solution methods.
Date: December 15, 2003
Creator: Casula, M; Galli, G; Saw, C; Zaitseva, N; Gerion, D; van Buuren, T et al.
System: The UNT Digital Library
Equilibrium constants for the hydrogen isotopic self-exchange reactions in the 4. 2-50. 0 K temperature range (open access)

Equilibrium constants for the hydrogen isotopic self-exchange reactions in the 4. 2-50. 0 K temperature range

Hydrogen fusion will require a mixture of liquefied or frozen D/sub 2/ and T/sub 2/. The equilibrium constant of the mixture describes the composition of this fuel. We have calculated the equilibrium constant, K/sub DT/, for the reaction D/sub 2/ + T/sub 2/ = 2DT in the 4.2-100 K temperature range. The results agree well with previous calculations at 25, 50, and 100 K. No calculations at temperatures below 25 K have been previously published. In the 16.7 to 33.3 K temperature range, which includes the triple point, K/sub DT/ can be represented by K = 2.995 exp (-10.82/T). The values of the analogous equilibrium constants for H/sub 2/--D/sub 2/ and H/sub 2/--T/sub 2/ are also given in the 4.2 to 50 K temperature range.
Date: December 15, 1976
Creator: Pyper, J. C. & Souers, P. C.
System: The UNT Digital Library
Computer Modeling of a Fusion Plasma (open access)

Computer Modeling of a Fusion Plasma

Progress in the study of plasma physics and controlled fusion has been profoundly influenced by dramatic increases in computing capability. Computational plasma physics has become an equal partner with experiment and traditional theory. This presentation illustrates some of the progress in computer modeling of plasma physics and controlled fusion.
Date: December 15, 2000
Creator: Cohen, B I
System: The UNT Digital Library
A Final Focus Model for Heavy Ion Fusion Driver System Codes (open access)

A Final Focus Model for Heavy Ion Fusion Driver System Codes

The need to reach high temperatures in an inertial fusion energy (IFE) target (or a target for the study of High Energy Density Physics, HEDP) requires the ability to focus ion beams down to a small spot. System models indicate that within the accelerator, the beam radius will be of order centimeters, whereas at the final focal spot on the target, a beam radius of order millimeters is required, so radial compression factors of order ten are required. The IFE target gain (and hence the overall cost of electricity) and the HEDP target temperature are sensitive functions of the final spot radius on target. Because of this sensitivity, careful attention needs to be paid to the spot radius calculation. We review our current understanding of the elements that enter into a systems model (such as emittance growth from chromatic, geometric, and non-linear space charge forces) for the final focus based on a quadrupolar magnet system.
Date: December 15, 2004
Creator: Barnard, J. J.; Bangerter, R. O.; Henestroza, E.; Kaganovich, I. D.; Logan, B. G.; Meier, W. R. et al.
System: The UNT Digital Library
A Numerical Algorithm for Complex Biological Flow in Irregular Microdevice Geometries (open access)

A Numerical Algorithm for Complex Biological Flow in Irregular Microdevice Geometries

We present a numerical algorithm to simulate non-Newtonian flow in complex microdevice components. The model consists of continuum viscoelastic incompressible flow in irregular microscale geometries. Our numerical approach is the projection method of Bell, Colella and Glaz (BCG) to impose the incompressibility constraint coupled with the polymeric stress splitting discretization of Trebotich, Colella and Miller (TCM). In this approach we exploit the hyperbolic structure of the equations of motion to achieve higher resolution in the presence of strong gradients and to gain an order of magnitude in the timestep. We also extend BCG and TCM to an embedded boundary method to treat irregular domain geometries which exist in microdevices. Our method allows for particle representation in a continuum fluid. We present preliminary results for incompressible viscous flow with comparison to flow of DNA and simulants in microchannels and other components used in chem/bio microdevices.
Date: December 15, 2003
Creator: Nonaka, A; Miller, G H; Marshall, T; Liepmann, D; Gulati, S; Trebotich, D et al.
System: The UNT Digital Library
The PHENIX experiment at RHIC (open access)

The PHENIX experiment at RHIC

Later this decade the Relativistic Heavy Ion Collider (RHIC) will be built at Brookhaven National Laboratory. Its goal will be to accelerate and collide Au beams at 100 GeV/c in an attempt to create a Quark Gluon Plasma (QGP). The PHENIX detector aims to detect the QGP through its leptonic and hadronic signatures. We describe here its physics capabilities and the details of the apparatus designed to pick out rare leptonic signatures from among hadronic multiplicities of up to 1500 particles per unit of rapidity.
Date: December 15, 1993
Creator: Tonse, S. R. & Thomas, J. H.
System: The UNT Digital Library
[Draft minutes of IAPG Mechanical Working Group meeting] (open access)

[Draft minutes of IAPG Mechanical Working Group meeting]

This report provides the draft minutes of the Interagency Advanced Power Group meeting held November 3--4, 1993. Topics addressed are: Materials for thermal management; photovoltaic programs in the Airforce; ground based radar advanced power system development program; battery research; generator prognostics & diagnostics equipment; a thermal flight experiment test program; power systems assessment; Overview: Phillip`s space thermal technologies branch; and development of actuator thermal management.
Date: December 15, 1993
Creator: Skinner, D. M.
System: The UNT Digital Library
Gamma-ray optical counterpart search experiment (GROCSE) (open access)

Gamma-ray optical counterpart search experiment (GROCSE)

The requirements of a gamma-ray burst optical counterpart detector are reviewed. By taking advantage of real-time notification of bursts, new instruments can make sensitive searches while the gamma-ray transient is still in progress. A wide field of view camera at Livermore National Laboratories has recently been adapted for detecting GRB optical counterparts to a limiting magnitude of 8. A more sensitive camera, capable of reaching m{sub upsilon} = 14, is under development.
Date: December 15, 1993
Creator: Akerlof, C.; Fatuzzo, M.; Lee, B.; Bionta, R.; Ledebuhr, A.; Park, H. S. et al.
System: The UNT Digital Library
Non-Salado flow and transport position paper. Revision 1 (open access)

Non-Salado flow and transport position paper. Revision 1

The US Department of Energy (DOE) is preparing to request the US Environmental Protection Agency (EPA) to certify compliance of the Waste Isolation Pilot Plant (WIPP) with long-term requirements of the environmental Radiation Protection Standards for Management and Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Waste (40 CFR Part 191). The DOE must also demonstrate compliance with the long-term requirements of the Land Disposal Restrictions of the Resource Conservation and Recovery Act (RCRA) (40 CFR Part 268.6). Sandia National Laboratories (SNL) has ben conducting iterative performance assessments (PAs) for the the WIPP to provide guidance to the project on the technical activities required to determine long-term performance of the WIPP disposal system. The most recent PA was conducted in 1992. The objectives of this paper are to: (1) Identify and describe the relationship between non-Salado hydrology and the array of scenarios that might be relevant to the long-term performance of the repository. (2) Identify and describe the array of conceptual and mechanistic models that are required to evaluate the scenarios for the purpose of compliance. (3) Identify and describe the data/information that are required to support the conceptual and mechanistic models.
Date: December 15, 1994
Creator: Axness, C.; Beauheim, R. & Behl, Y.
System: The UNT Digital Library
Attractive characteristics of mirrors (open access)

Attractive characteristics of mirrors

A summary of the attractive characteristics of mirror devices is presented. Recent progress in development of axisymmetric mirror devices is described. Potentialities of mirrors as a basis for D{sup 3}He fusion power generators and high-flux neutron sources for fusion material tests are discussed.
Date: December 15, 1994
Creator: Post, R. F. & Ryutov, D. D.
System: The UNT Digital Library
Recent developments in complex scaling (open access)

Recent developments in complex scaling

Some recent developments in the use of complex basis function techniques to study resonance as well as certain types of non-resonant, scattering phenomena are discussed. Complex scaling techniques and other closely related methods have continued to attract the attention of computational physicists and chemists and have now reached a point of development where meaningful calculations on many-electron atoms and molecules are beginning to appear feasible.
Date: December 15, 1980
Creator: Rescigno, T. N.
System: The UNT Digital Library
Saturation of hot CO/sub 2/ at 10. 6. mu. m (open access)

Saturation of hot CO/sub 2/ at 10. 6. mu. m

Saturation of the short laser pulse transmission of hot CO/sub 2/ has been studied experimentally and theoretically. Pure CO/sub 2/ at 200 torr and 400 +- 3/sup 0/C was contained in a special temperature-controlled 118 cm absorption cell. The cell's energy transmission was measured as a function of the incident pulse's fluence. The incident pulses' wavelengths were either at the P18 or P20 lines of the 10.6 ..mu..m band, and their temporal shape (FWHM of 1.6 ns) was kept fixed as the fluence was changed. The data showed that the absorption of hot CO/sub 2/ saturated differently at the two wavelengths, with the P20 transition being the harder to saturate.
Date: December 15, 1980
Creator: Goldstein, J. C.; Czuchlewski, S. J. & Nowak, A. V.
System: The UNT Digital Library
Pulse propagation in a one-atmosphere CO/sub 2/ laser amplifier (open access)

Pulse propagation in a one-atmosphere CO/sub 2/ laser amplifier

The theoretical propagation of short (150-ps) laser pulses in a one-atmosphere CO/sub 2/ amplifier is investigated using a fully coherent density-matrix computer code. The influence of coherent effects and of the response times of the amplifying medium on the temporal shape of the output pulse is examined. It is found that short pulses, whose width is approximately equal to the T/sub 2/ time of the medium, can be effectively amplified.
Date: December 15, 1980
Creator: Czuchlewski, Stephen J.
System: The UNT Digital Library
Advances in optical materials for large aperture lasers (open access)

Advances in optical materials for large aperture lasers

Lawrence Livermore National Laboratory (LLNL) is using large aperture Nd: glass lasers to investigate the feasibility of inertial confinement fusion. In our experiments high power laser light is focussed onto a small (100 to 500 micron) target containing a deuterium-tritium fuel mixture. During the short (1 to 5 ns) laser pulse the fuel is compressed and heated, resulting in fusion reactions. The generation and control of the powerful laser pulses for these experiments is a challenging scientific and engineering task, which requires the development of new optical materials, fabrication techniques, and coatings. LLNL with the considerable cooperation and support from the optical industry, where most of the research and development and almost all the manufacturing is done, has successfully applied several new developments in these areas.
Date: December 15, 1981
Creator: Stokowski, S. E.; Lowdermilk, W. H.; Marchi, F. T.; Swain, J. E.; Wallerstein, E. P. & Wirtenson, G. R.
System: The UNT Digital Library
Occurrence and use of complex resonances (poles in scattering and radiation problems) (open access)

Occurrence and use of complex resonances (poles in scattering and radiation problems)

In a wide variety of physics problems, especially those which involve wave phenomena such as in electromagnetics and acoustics, a behavior results that can be described by systems of linear (partial) differential equations. Solutions to such problems often can be expressed simply in the form of an exponential series. Some specific background material for this approach is discussed, and a variety of example applications is summarized. (WHK)
Date: December 15, 1981
Creator: Miller, E. K.
System: The UNT Digital Library
Heavy leptons at the SSC (open access)

Heavy leptons at the SSC

It is argued that detection of heavy leptons at the Superconducting Super Collider seems to be very difficult but perhaps not impossible. The feasibility is shown to depend critically upon the ability to identify events with W's decaying hadronically and missing transverse momentum. (LEW)
Date: December 15, 1987
Creator: Anderson, G. & Hinchliffe, I.
System: The UNT Digital Library
PERTURBATION THEORY OF MANY-BOSON SYSTEMS (open access)

PERTURBATION THEORY OF MANY-BOSON SYSTEMS

A noncanonical transformation of the boson creation and annihilation operators is performed in order to obtain a Hamiltonian which can be treated by the standard methods of field-theoretic perturbation theory. The standard results of Belyaev (with a slight modification) are rederived by this technique. (auth)
Date: December 15, 1962
Creator: Kromminga, A.J. & Bolsterli, M.
System: The UNT Digital Library
Spent fuel shipping, reprocessing, and recycle fabrication in the HTGR fuel cycle (open access)

Spent fuel shipping, reprocessing, and recycle fabrication in the HTGR fuel cycle

From joint power generation conference; New Orleans, Louasiana, USA (16 Sep 1973). The High Temperature Gas Cooled Reactor (HTGR) fuel recycle operation is described. The description includes the HTGR spent fuel shipping system and the proposed method of reprocessing the spent fuel to recover the bred /sup 233/U and /sup 235/U. The process for refabricating the recovered fuel into recycle fuel is also discussed. (auth)
Date: December 15, 1972
Creator: Brooks, L. H.; Davis, C. R.; Peterman, D. D. & Spaeth, M. E.
System: The UNT Digital Library
Analysis of micro-structural relaxation phenomena in laser-modified fused silica using confocal Raman microscopy (open access)

Analysis of micro-structural relaxation phenomena in laser-modified fused silica using confocal Raman microscopy

Fused silica micro-structural changes associated with localized 10.6 {micro}m CO{sub 2} laser heating are reported. Spatially-resolved shifts in the high-frequency asymmetric stretch transverse-optic (TO) phonon mode of SiO{sub 2} were measured using confocal Raman microscopy, allowing construction of axial fictive temperature (T{sub f}) maps for various laser heating conditions. A Fourier conduction-based finite element model was employed to compute on-axis temperature-time histories, and, in conjunction with a Tool-Narayanaswamy form for structural relaxation, used to fit T{sub f}(z) profiles to extract relaxation parameters. Good agreement between the calculated and measured T{sub f} was found, yielding reasonable values for relaxation time and activation enthalpy in the laser-modified silica.
Date: December 15, 2009
Creator: Matthews, M.; Vignes, R.; Cooke, J.; Yang, S. & Stolken, J.
System: The UNT Digital Library