Matrix Description of Intersecting M5 Branes (open access)

Matrix Description of Intersecting M5 Branes

Novel 3+1 dimensional N = 2 superconformal field theories (with tensionless BPS string solitons) are believed to arise when two sets of M5 branes intersect over a 3+1 dimensional hyperplane. We derive a DLCQ description of these theories as supersymmetric quantum mechanics on the Higgs branch of suitable 4d N = 1 supersymmetric gauge theories. Our formulation allows us to determine the scaling dimensions of certain chiral primary operators in the conformal field theories. We also discuss general criteria for quantum mechanical DLCQ descriptions of supersymmetric field theories (and the resulting multiplicities and scaling dimensions of chiral primary operators).
Date: March 5, 1998
Creator: Kachru, Shamit; Oz, Yaron & Yin, Zheng
System: The UNT Digital Library
MSET modeling of Crystal River-3 venturi flow meters. (open access)

MSET modeling of Crystal River-3 venturi flow meters.

The analysis of archived Crystal River-3 feedwater flow data reveals a slow and steady degradation of the flow meter measurements during the 1992/1993 operating cycle. MSET can reliably estimate the true flow rate and quantify the degree of departure between the indicated signal and the true flow rate with high accuracy. The MSET computed flow rate could, in principle, be used to provide an improved estimate of the reactor power and hence avoid the revenue loss associated with derating the reactor based on a faulty feedwater flow rate indication.
Date: January 5, 1998
Creator: Bockhorst, F. K.; Gross, K. C.; Herzog, J. P. & Wegerich, S. W.
System: The UNT Digital Library
Advances in processing of Ag-sheathed (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconductors. (open access)

Advances in processing of Ag-sheathed (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} superconductors.

Advances in the processing and fabrication of Ag-sheathed (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) high-T{sub c} superconductors by the powder-in-tube technique continue to bring this material closer to commercial applications. Enhancement of the transport critical current density (J{sub c}) of Ag-sheathed Bi-2223 tapes was achieved by increasing the packing density of the precursor powder, improving mechanical deformation, and adjusting the cooling rate. Long lengths (>150 m) of multifilamentary Bi-2223 tapes have been fabricated and carry critical currents (I{sub c}) of >50 A (J{sub c} {approx} 25 kA/cm{sup 2}) at 77 K in self-field. A 1260-m-long tape carried an I{sub c} of 18 A (J{sub c} {approx} 12 kA/cm{sup 2}) from end-to-end. Several prototype coils have been assembled from these long-length tapes. Recent progress in the fabrication of Bi-2223 tapes is presented in this paper.
Date: March 5, 1998
Creator: Balachandran, U.; Eror, N. G.; Haldar, P. & Lelovic, M.
System: The UNT Digital Library
Measurement of low levels of alpha in {sup 99}Mo product solutions. (open access)

Measurement of low levels of alpha in {sup 99}Mo product solutions.

The conclusions of this report are that molybdenum can effectively be separated from uranium and plutonium using TRU-Resin; and that separation of the {sup 99}Mo from the actinides will reduce the analyst's exposure and simplify analysis for the actinide elements.
Date: March 5, 1998
Creator: Conner, C.; Liberatore, M. W.; Sedlet, J. & Vandegrift, G. F.
System: The UNT Digital Library
Modeling the effect of irradiation and post-irradiation annealing on grain boundary composition in austenitic Fe-Cr-Ni alloys. (open access)

Modeling the effect of irradiation and post-irradiation annealing on grain boundary composition in austenitic Fe-Cr-Ni alloys.

Many irradiation effects in Fe-Cr-Ni alloys such as radiation-induced segregation, radiation-enhanced diffusion, and void swelling are known to vary with bulk alloy composition. The development of microstructural and microchemical changes during irradiation and during post-irradiation annealing is determined by the rate of diffusion of point defects and alloying elements. To accurately predict the changes in grain boundary chemistry due to radiation-induced segregation and post-irradiation annealing, the composition dependence of diffusion parameters, such as the migration energy, must be known. A model has been developed which calculates migration diffusivity. The advantages of this calculational method are that a single set of input parameters can be used for a wide range of bulk alloy compositions, and the effects of local order can easily be incorporated into the calculations. A description of the model is presented, and model calculations are compared to segregation measurements from seven different iron-chromium-nickel alloys, irradiated with protons to doses from 0.1 to 3.0 dpa at temperatures between 200 C and 600 C. Results show that segregation trends can be modeled using a single set of input parameters with the difference between model calculation and measurement being less than 5 at%, but usually less than 2 at%. Additionally, model …
Date: March 5, 1998
Creator: Allen, T.; Busby, J. T.; Kenik, E. A. & Was, G. S.
System: The UNT Digital Library
Spectroscopic determination of C{sub 2} in Ar/H{sub 2}/CH{sub 4} and Ar/H{sub 2}/C{sub 60} microwave plasmas for nanocrystalline diamond synthesis. (open access)

Spectroscopic determination of C{sub 2} in Ar/H{sub 2}/CH{sub 4} and Ar/H{sub 2}/C{sub 60} microwave plasmas for nanocrystalline diamond synthesis.

We have measured the steady state concentration of gas phase C{sub 2} in Ar/H{sub 2}/CH{sub 4} and Ar/H{sub 2}/C{sub 60} microwave plasmas used for the deposition of nanocrystalline diamond films. High sensitivity white light absorption spectroscopy is used to monitor the C{sub 2} density using the d{sup 3}II {l_arrow} A{sup 3}II (0,0) vibrational band of C{sub 2} as chamber pressure, microwave power, substrate temperature and feed gas mixtures are varied in both chemistries. Understanding how these parameters influence the C{sub 2} density in the plasma volume provides insight into discharge mechanisms relevant to the deposition of nanocrystalline diamond.
Date: February 5, 1998
Creator: Goyette, A. N.; Lawler, J. E.; Anderson, L. W.; Gruen, D. M.; McCauley, T. G.; Zhou, D. et al.
System: The UNT Digital Library
The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys. (open access)

The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys.

The magnitudes of both void swelling and radiation-induced segregation (RIS) in iron-chromium-nickel alloys are dependent on bulk alloy composition. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation. This local composition change reduces the subsequent vacancy flux to the void, thereby reducing void swelling. In this work, the resistance to swelling from major element segregation is estimated using diffusivities derived from grain boundary segregation measurements in irradiated iron-chromium-nickel alloys. The resistance to void swelling in iron- and nickel-base alloys correlates with the segregation and both are functions of bulk alloy composition. Alloys that display the greatest amount of nickel enrichment and chromium depletion are found to be most resistant to void swelling, as predicted. Additionally, swelling is shown to be greater in alloys in which the RIS profiles are slow to develop.
Date: March 5, 1998
Creator: Allen, T. R.; Busby, J. T.; Kenik, E. A. & Was, G. S.
System: The UNT Digital Library
Progress on the relativistic klystron two-beam accelerator prototype (open access)

Progress on the relativistic klystron two-beam accelerator prototype

The technical challenge for making two-beam accelerators into realizable power sources lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2-kA, l-MeV, electron induction prototype injector as a collaborative effort between LBL and LLNL. The electron source will be a 3.5"-diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 120-ns flat top (1% energy variation), and a normalized edge emittance of less than 200 {pi}-mm-mr. Planned diagnostics include an isolated cathode with resistive divider for direct measurement of current emission, resistive-wall and magnetic probe current monitors for measuring beam current and centroid position, capacitive probes for measuring A-K gap voltage, an energy spectrometer, and a pepper-pot emittance diagnostic. Details of the injector, beam line, and diagnostics are presented.
Date: July 5, 1998
Creator: Anderson, D. E.; Eylon, S.; Henestroza, E.; Houck, T. L.; Lidia, S. M.; Vanecek, D. L. et al.
System: The UNT Digital Library
Terawatt Picosecond CO(sub 2) Laser Technology for High Energy Physics Applications (open access)

Terawatt Picosecond CO(sub 2) Laser Technology for High Energy Physics Applications

Demonstration of ultra-high acceleration gradients in the SM LWFA experiments put a next objective for the laser accelerator development to achieve a low-emittance monochromatic acceleration over extended interaction distances. The emerging picosecond terawatt (ps-TW) CO{sub 2} laser technology helps to meet this strategic goal. Among the considered examples are: the staged electron laser accelerator (STELLA) experiment, which is being conducted at the Brookhaven ATF, and the plasma-channeled LWFA. The long-wavelength and high average power capabilities of CO{sub 2} lasers maybe utilized also for generation of intense x-ray and gamma radiation through Compton back-scattering of the laser beams off relativistic electrons. We discuss applications of ps-TW CO{sub 2} lasers for a tentative {gamma}-{gamma} (or {gamma}-lepton) collider and generation of polarized positron beams.
Date: July 5, 1998
Creator: Pogorelsky, I. V.
System: The UNT Digital Library
STELLA Experiment: Design and Model Predictions (open access)

STELLA Experiment: Design and Model Predictions

The STaged ELectron Laser Acceleration (STELLA) experiment will be one of the first to examine the critical issue of staging the laser acceleration process. The BNL inverse free electron laser (EEL) will serve as a prebuncher to generate {approx} 1 {micro}m long microbunches. These microbunches will be accelerated by an inverse Cerenkov acceleration (ICA) stage. A comprehensive model of the STELLA experiment is described. This model includes the EEL prebunching, drift and focusing of the microbunches into the ICA stage, and their subsequent acceleration. The model predictions will be presented including the results of a system error study to determine the sensitivity to uncertainties in various system parameters.
Date: July 5, 1998
Creator: Kimura, W. D.; Babzien, M.; Ben-Zvi, Ilan; Campbell, L. P.; Cline, D. B.; Fiorito, R. B. et al.
System: The UNT Digital Library
Evaluation of the ISUS Power Management and Distribution System Under Operational Conditions (open access)

Evaluation of the ISUS Power Management and Distribution System Under Operational Conditions

An operational evaluation of the Integrated Solar Upper Stage (ISUS) power management and distribution (PMAD) system was conducted as part of the Engine Ground Demonstration thermionic power system test program-- START-3. START-3 testing took place at the Baikal Test Stand, located in the University of New Mexico's Energy Conversion Research Laboratory at the New Mexico Engineering Research Institute in Albuquerque, NM. One objective of this test was to evaluate the operational performance of the lSUS PMAD system developed by the National Aeronautics and Space Administration (NASA) Lewis Research Center. Tests of the PMAD with the ISUS diode string demonstrated that the PMAD could regulate the output of an array of thermionic converters within the design requirements and couId be modified to optimize performance for diode strings of fewer than 16 diodes.
Date: October 5, 1998
Creator: Button, R.M.; Luker, S.M.; Nelson, MAJ R.C. & Wyant, F.J.
System: The UNT Digital Library
ACCOMPLISHMENTS OF THE AMERICAN-POLISH PROGRAM FOR ELIMINATION OF LOW EMISSIONS IN KRAKOW (open access)

ACCOMPLISHMENTS OF THE AMERICAN-POLISH PROGRAM FOR ELIMINATION OF LOW EMISSIONS IN KRAKOW

In 1991, US and Polish officials signed a Memorandum of Understanding formally initiating and directing the Cracow Clean Fossil Fuels and Energy Efficiency Program. Developing a program approach for the most effective use of the available funds required considerable effort on the part of all project participants. The team recognized early that the cost of solving the low emissions problem even in only one city far exceeded the amount of available US funds. Economic conditions in Poland limited availability of local capital funds for environmental projects. Imposing environmental costs on struggling companies or city residents under difficult conditions of the early 1990's required careful consideration of the economic and political impacts. For all of these reasons the program sought to identify technologies for achieving air quality goals which, through improved efficiency and/or reduced fuel cost, could be so attractive economically as to lead to self-sustaining activities beyond the end of the formal project. The effort under this program has been focused into 5 main areas of interest as follows: (1) Energy Conservation and Extension of Central Station District Heating; (2) Replacement of Coal- and Coke-Fired Boilers with Natural Gas-Fired Boilers; (3) Replacement of Coal-Fired Home Stoves with Electric Heating Appliances; …
Date: November 5, 1998
Creator: BUTCHER,T.A. & PIERCE,B.
System: The UNT Digital Library
Preliminary Ionization Efficiencies of {sup 11}C and {sup 14}O with the LBNL ECR Ion Sources (open access)

Preliminary Ionization Efficiencies of {sup 11}C and {sup 14}O with the LBNL ECR Ion Sources

High charge states, up to fully stripped {sup 11}C and {sup 14}O ion, beams have been produced with the electron cyclotron resonance ion sources (LBNL, ECR and AECR-U) at Lawrence Berkeley National Laboratory. The radioactive atoms of {sup 11}C and {sup 14}O were collected in batch mode with an LN{sub 2} trap and then bled into the ECR ion sources. Ionization efficiency as high as 11% for {sup 11}C{sup 4+} was achieved.
Date: October 5, 1998
Creator: Xie, Z.Q.; Cerny, J.; Guo, F.Q.; Joosten, R.; Larimer, R.M.; Lyneis, C.M. et al.
System: The UNT Digital Library
Hydrochlorofluorocarbon Reactivity and Structural Characterization of Zinc Exchanged NaX (open access)

Hydrochlorofluorocarbon Reactivity and Structural Characterization of Zinc Exchanged NaX

None
Date: July 5, 1998
Creator: Ciraolo, M. F.; Norby, P.; Hanson, J. C.; Corbin, D. R. & Grey, C. P.
System: The UNT Digital Library
POLARIZATION AND LUMINOSITY REQUIREMENTS FOR THE FIRST MUON COLLIDER. (open access)

POLARIZATION AND LUMINOSITY REQUIREMENTS FOR THE FIRST MUON COLLIDER.

None
Date: July 5, 1998
Creator: PARSA,Z.
System: The UNT Digital Library
Characterization of K{Sup +} Ion Exchange Into Na-Lsx Using Time Resolved Synchrotron X-Ray Powder Diffraction and Rietveld Refinement (open access)

Characterization of K{Sup +} Ion Exchange Into Na-Lsx Using Time Resolved Synchrotron X-Ray Powder Diffraction and Rietveld Refinement

None
Date: July 5, 1998
Creator: Lee,Y.; Cahill, C. L.; Hanson, J. C.; Parise, J. B.; Carr, S. W.; Myrick, M. L. et al.
System: The UNT Digital Library
Development of a radioactive ion beam test stand at LBNL (open access)

Development of a radioactive ion beam test stand at LBNL

For the on-line production of a {sup 14}O{sup +} ion beam, an integrated target--transfer line ion source system is now under development at LBNL. {sup 14}O is produced in the form of CO in a high temperature carbon target using a 20 MeV {sup 3}He beam from the LBNL 88'' Cyclotron via the reaction {sup 12}C({sup 3}He,n){sup 14}O. The neutral radioactive CO molecules diffuse through an 8 m room temperature stainless steel line from the target chamber into a cusp ion source. The molecules are dissociated, ionized and extracted at energies of 20 to 30 keV and mass separated with a double focusing bending magnet. The different components of the setup are described. The release and transport efficiency for the CO molecules from the target through the transfer line was measured for various target temperatures. The ion beam transport efficiencies and the off-line ion source efficiencies for Ar, O{sub 2} and CO are presented. Ionization efficiencies of 28% for Ar{sup +}, 1% for CO, 0.7% for O{sup +}, 0.33 for C{sup +} have been measured.
Date: October 5, 1998
Creator: Burke, J.; Freedman, S. J.; Fujikawa, B.; Gough, R. A.; Lyneis, C. M.; Vetter, P. et al.
System: The UNT Digital Library
Results from the Microminiature Thermionic Converter Demonstration Testing Program (open access)

Results from the Microminiature Thermionic Converter Demonstration Testing Program

Research is in progress to develop microminiature thermionic converters (MTCS) with high energy conversion efficiencies and variable operating temperatures using semiconductor integrated circuit (IC) fabrication methods. The use of IC techniques allows the fabrication of MTCS with cathode to anode spacing of several microns or less and with anode and cathode materials that will have work fimctions ranging from 1 eV to 3 eV. The small cathode to anode spacing and variable electrode work functions should allow the conversion of heat energy to relatively large current densities (up to tens of Amps/cmz) at relatively high conversion efficiencies ( 15-25%).
Date: October 5, 1998
Creator: King, D.B.; Luke, J.R. & Wyant, F.J.
System: The UNT Digital Library
Relativistic-klystron two-beam accelerator as a power source for future linear colliders (open access)

Relativistic-klystron two-beam accelerator as a power source for future linear colliders

The technical challenge for making two-beam accelerators into realizable power sources for high-energy colliders lies in the creation of the drive beam and in its propagation over long distances through multiple extraction sections. This year we have been constructing a 1.2&A, l-MeV, induction gun for a prototype relativistic klystron two-beam accelerator (RK-TBA). The electron source will be a 8.9 cm diameter, thermionic, flat-surface cathode with a maximum shroud field stress of approximately 165 kV/cm. Additional design parameters for the injector include a pulse length of over 150-ns flat top (1% energy variation), and a normalized edge emittance of less than 300 pi-mm-n-n. The prototype accelerator will be used to study physics, engineering, and costing issues involved in the application of the RK-TBA concept to linear colliders. We have also been studying optimization parameters, such as frequency, for the application of the RK-TBA concept to multi-TeV linear colliders. As an rf power source the RK-TBA scales favorably up to frequencies around 35 GHz. An overview of this work with details of the design and performance of the prototype injector, beam line, and diagnostics will be presented.
Date: October 5, 1998
Creator: Anderson, D. E.; Eylon, S.; Henestroza, E.; Houck, T. L.; Lidia, M.; Vanecek, D. L. et al.
System: The UNT Digital Library
Measured Ni-63 Contents in Savannah River Site High Level Waste and Defense Waste Processing Facility Glass Product by Ni-Selective Ion Exchange Purification and b-Decay Counting (open access)

Measured Ni-63 Contents in Savannah River Site High Level Waste and Defense Waste Processing Facility Glass Product by Ni-Selective Ion Exchange Purification and b-Decay Counting

In this paper is described tests of EiChrom Industries' Ni-selective ion exchange resin for use in analysis of Ni-63 in Savannah River Site high level waste.
Date: October 5, 1998
Creator: Dewberry, R. A.
System: The UNT Digital Library
Real time programming environment for Windows, Appendix A (open access)

Real time programming environment for Windows, Appendix A

This appendix contains all source code for the RTProE system. The following file contents are included: pdb.h; hgen.l; hgen.y; igen.l; igen.y; pdm.l; pdm.y; rtdata.l; rtdata.y; framegen.c; librt.c; librt.h; rtsched.c; build.tsh; sde.tcl; rtsched.def.
Date: April 5, 1998
Creator: unknown
System: The UNT Digital Library
Short course on St-02 applications of isotope dilutions and isotopic measurements (open access)

Short course on St-02 applications of isotope dilutions and isotopic measurements

This short course includes information on these topics and subtopics: (I) Nuclear Properties: (A) Historic roots; (B) Nomenclature; (C) Nuclear Stability and abundance; (D) Uses of isotopic techniques; (II) Instrumentation: (A) Sources; (B) Mass resolving elements; (C) Detectors; (III) Making Isotopic Measurements by ICP-MS: (A) Deadtime Correction; (B) Mass Discrimination; (C) Signal /Noise considerations; (IV) Applications and examples: (A) Isotope dilution; (B) Double Spike; (C) Biological Application; (D) Environmental Application; (E) Geological.
Date: January 5, 1998
Creator: Miller, P.
System: The UNT Digital Library
Isobar Separators for Radioactive Ion Beam Facilities (open access)

Isobar Separators for Radioactive Ion Beam Facilities

A radioactive ion beam facility - in short a RIB facility - produces ions of short-lived nuclei and accelerates them to energies of 0.1�10 MeV per nucleon or even higher. In this process it is important that the resulting RIB beams are free from nuclei of neighboring isobars or of neighboring elements. This task requires the production and ionization of the nuclei of interest as well as separating them from all others with a high-mass resolving power and small-mass cross contaminations. When constructing such a facility it also is very important to find ways that allow the accelerated ions to be provided to different experiments at least quasi simultaneously.
Date: October 5, 1998
Creator: Garrett, J.D. & Wollnik, H.
System: The UNT Digital Library
Characterization of fluence limiting defects in hafnia/silica multilayer coatings manufactured for the National Ignition Facility (open access)

Characterization of fluence limiting defects in hafnia/silica multilayer coatings manufactured for the National Ignition Facility

A variety of microscopic techniques are employed to characterize fluence limiting defects in hafnia/silica multilayer coatings manufactured for the National Ignition Facility.
Date: February 5, 1998
Creator: Wu, Z. L., LLNL
System: The UNT Digital Library