Bumps and poles in the S-matrix: A systematic study of 0 sup ++ and 2 sup ++ mesons plus a molecule approach to the E(1420) in the K K. pi. system (open access)

Bumps and poles in the S-matrix: A systematic study of 0 sup ++ and 2 sup ++ mesons plus a molecule approach to the E(1420) in the K K. pi. system

The goal of Hadron Spectroscopy is to find the spectrum of states formed by color singlet arrangements of quarks and gluons. Ideally these spectral states are associated with poles of the scattering matrix of hadrons which are the decay channels of the states. For example the {rho} meson is the lowest q{bar q} s-wave, spin one color singlet state and decays into {pi}{sup +}{pi}{sup -}. Since the {rho}decays in a relative p-wave, one finds the {rho} pole in the I = 1 p-wave {pi}{pi} phase shifts. There are forces between quarks and gluons which do not manifest themselves as true resonances and thus cannot be described by a Breit-Wigner pole. I will give some examples that are not Breit-Wigner poles of the scattering matrix but are important bumps in meson production. 22 refs., 10 figs.
Date: November 16, 1989
Creator: Longacre, R. S.
Object Type: Article
System: The UNT Digital Library
Magnetic shielding tests for MFTF-B neutral beamlines (open access)

Magnetic shielding tests for MFTF-B neutral beamlines

A test program to determine the effectiveness of various magnetic shielding designs for MFTF-B beamlines was established at Lawrence Livermore National Laboratory (LLNL). The proposed one-tenth-scale shielding-design models were tested in a uniform field produced by a Helmholtz coil pair. A similar technique was used for the MFTF source-injector assemblies, and the model test results were confirmed during the Technology Demonstration in 1982. The results of these tests on shielding designs for MFTF-B had an impact on the beamline design for MFTF-B. The iron-core magnet and finger assembly originally proposed were replaced by a simple, air-core, race-track-coil, bending magnet. Only the source injector needs to be magnetically shielded from the fields of approximately 400 gauss.
Date: November 16, 1983
Creator: Kerns, J.; Fabyan, J.; Wood, R. & Koger, P.
Object Type: Article
System: The UNT Digital Library
Technological implications of SNAP reactor power system development on future space nuclear power systems (open access)

Technological implications of SNAP reactor power system development on future space nuclear power systems

Nuclear reactor systems are one method of satisfying space mission power needs. The development of such systems must proceed on a path consistent with mission needs and schedules. This path, or technology roadmap, starts from the power system technology data base available today. Much of this data base was established during the 1960s and early 1970s, when government and industry developed space nuclear reactor systems for steady-state power and propulsion. One of the largest development programs was the Systems for Nuclear Auxiliary Power (SNAP) Program. By the early 1970s, a technology base had evolved from this program at the system, subsystem, and component levels. There are many implications of this technology base on future reactor power systems. A review of this base highlights the need for performing a power system technology and mission overview study. Such a study is currently being performed by Rockwell's Energy Systems Group for the Department of Energy and will assess power system capabilities versus mission needs, considering development, schedule, and cost implications. The end product of the study will be a technology roadmap to guide reactor power system development.
Date: November 16, 1982
Creator: Anderson, R.V.
Object Type: Report
System: The UNT Digital Library
Three wavelength optical alignment of the Nova laser (open access)

Three wavelength optical alignment of the Nova laser

The Nova laser, presently under construction at Lawrence Livermore National Laboratory, will be capable of delivering more than 100 kJ of focused energy to an Inertial Confinement Fusion (ICF) target. Operation at the fundamental wavelength of the laser (1.05 ..mu..m) and at the second and third harmonic will be possible. This paper will discuss the optical alignment systems and techniques being implemented to align the laser output to the target at these wavelengths prior to each target irradiation. When experiments require conversion of the laser light to wavelengths of 0.53 ..mu..m and 0.35 ..mu..m prior to target irradiation, this will be accomplished in harmonic conversion crystals located at the beam entrances to the target chamber. The harmonic alignment system will be capable of introducing colinear alignment beams of all three wavelengths into the laser chains at the final spatial filter. The alignment beam at 1.05 ..mu..m will be about three cm in diameter and intense enough to align the conversion crystals. Beams at 0.53 ..mu..m and 0.35 ..mu..m will be expanded by the spatial filter to full aperture (74 cm) and used to illuminate the target and other alignment aids at the target chamber focus. This harmonic illumination system will …
Date: November 16, 1983
Creator: Swift, C. D.; Bliss, E. S.; Jones, W. A. & Seppala, L. G.
Object Type: Article
System: The UNT Digital Library
Establishment and maintenance of a coal sample bank and data base (open access)

Establishment and maintenance of a coal sample bank and data base

For each sample, one 30-gallon drum containing approximately 90 lb of coal at {minus}1/4 inch was designated for headspace oxygen analysis and coal quality monitoring at yearly intervals. Headspace oxygen analysis and retrieval of a 5-lb sample for coal analysis have begun. Headspace oxygen contents are shown in Table 1. Preparation and analysis of these samples for the second yearly quality evaluation is in progress. We have initiated a study of different means of storage in preventing sample deterioration and in maintaining an inert headspace atmosphere. The work was performed with support from the Penn State Cooperative Program in Coal Research. A run-of-mine sample of medium-volatile bituminous Lower Kittanning coal was collected as PSOC-1536 and promptly processed. Gieseler fluidity FSI, alkali extraction and preparation of petrographic pellets were accomplished within 32 hours of extraction of the coal from the mine face. Splits of the sample were sealed under argon in several container types.
Date: November 16, 1989
Creator: Davis, A.
Object Type: Report
System: The UNT Digital Library
Projections of transport scaling laws for small toroidal reactors (open access)

Projections of transport scaling laws for small toroidal reactors

Transport in present day Spheromaks is dominated by impurity radiation. Fortunately, this is largely from oxygen and carbon, not metal vapor from the walls of the vessel on plasma guns and it is expected this loss can be eliminated by improved technique. The formation and gross MHD stability properties of these plasmas are quite well understood and so the reactor predictions depend on estimates of the energy loss rates from the plasma. In the absence of significant experimental data one is driven to consider other related devices. Tokamaks show classical ion transport, scaling with 1/B/sup 2/, but anomalous electron transport which is very insensitive to magnetic field, the well known Alcator scaling. The scaling of the Spheromak to a reactor size still produces favorable Q values with these pessimistic results. The reactor is small, with power output in the 10 to 50 MW range, but this could be deployed as a multiple unit power station, with good reliability due to the duplication, or as a small power unit for a ship or remote site. It also makes an attractive test reactor for the near term.
Date: November 16, 1981
Creator: McNamara, B.
Object Type: Article
System: The UNT Digital Library
Supplementary information on Series II Test A-5 test conditions (open access)

Supplementary information on Series II Test A-5 test conditions

Test planning and test preparation for LLTR Series II Test A-5 are continuing at GE and ETEC. The main objective for this test is to obtain data on the type and magnitude of steam tube blowout failures resulting from worst case leak conditions under the superheater hot standby condition (i.e., the plant condition considered most susceptible to steam tube blowout failures from wastage/overheating). A corollary objective is to add large quantities of steam (i.e. approx. 330 lbs) to simulate the amount that could be added in a plant system (such as CRBRP) before pressure would build up in the intermediate Heat Transport System to blow the expansion tank rupture disc. This report recommends the preferred method for operating the LLTR primary/secondary steam systems for Test A-5. i.e., Option 5 - Common Supply Tanks for Primary and Secondary Systems.
Date: November 16, 1981
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Inertial-confinement-fusion targets (open access)

Inertial-confinement-fusion targets

Inertial confinement fusion (ICF) targets are made as simple flat discs, as hollow shells or as complicated multilayer structures. Many techniques have been devised for producing the targets. Glass and metal shells are made by using drop and bubble techniques. Solid hydrogen shells are also produced by adapting old methods to the solution of modern problems. Some of these techniques, problems and solutions are discussed. In addition, the applications of many of the techniques to fabrication of ICF targets is presented.
Date: November 16, 1981
Creator: Hendricks, C.D.
Object Type: Article
System: The UNT Digital Library
Benchmark of the IMPACT Code for High Intensity Beam DynamicsSimulation (open access)

Benchmark of the IMPACT Code for High Intensity Beam DynamicsSimulation

The IMPACT (Integrated Map and Particle Accelerator Tracking) code was first developed under Computational Grand Challenge project in the mid 1990s [1]. It started as a three-dimensional (3D) data parallel particle-in-cell (PIC) code written in High Performance Fortran. The code used a split-operator based method to solve the Hamiltonian equations of motion. It contained linear transfer maps for drifts, quadrupole magnets and rf cavities. The space-charge forces were calculated using an FFT-based method with 3D open boundary conditions and longitudinal periodic boundary conditions. This code was completely rewritten in the late 1990s based on a message passing parallel programming paradigm using Fortran 90 and MPI following an object-oriented software design. This improved the code's scalability on large parallel computer systems and also gave the code better software maintainability and extensibility [2]. In the following years, under the SciDAC-1 accelerator project, the code was extended to include more accelerating and focusing elements such as DTL, CCL, superconducting linac, solenoid, dipole, multipoles, and others. Besides the original split-operator based integrator, a direct integration of Lorentz equations of motion using a leap-frog algorithm was also added to the IMPACT code to handle arbitrary external nonlinear fields. This integrator can read in 3D electromagnetic …
Date: November 16, 2006
Creator: Qiang, J. & Ryne, R.D.
Object Type: Article
System: The UNT Digital Library
Lepton Flavour Violation And Baryon Number Non-Conservation in tau to Lambda + h (open access)

Lepton Flavour Violation And Baryon Number Non-Conservation in tau to Lambda + h

We have searched for the violation of baryon number B and lepton number L in the (B - L)-conserving modes {tau}{sup -} {yields} {bar {Lambda}}{pi}{sup -} and {tau}{sup -} {yields} {bar {Lambda}}K{sup -} as well as the (B - L)-violating modes {tau}{sup -} {yields} {Lambda}{pi}{sup -} and {tau}{sup -} {yields} {Lambda}K{sup -} using 237 fb{sup -1} of data collected with the BaBar detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage rings. We do not observe any signal and we determine preliminary upper limits on the branching fractions {Beta}({tau}{sup -} {yields} {bar {Lambda}}{pi}{sup -}) < 5.9 x 10{sup -8}, {Beta}({tau}{sup -}{yields} {Lambda}{pi}{sup -}) < 5.8 x 10{sup -6}, {Beta}({tau}{sup -} {yields} {bar {Lambda}}K{sup -}) < 7.2 x 10{sup -8}, and {Beta}({tau}{sup -} {yields} {Lambda}K{sup -}) < 15 x 10{sup -8} at 90% confidence level.
Date: November 16, 2007
Creator: Lafferty, G.D.
Object Type: Article
System: The UNT Digital Library
Commissioning Results of the LCLS Injector (open access)

Commissioning Results of the LCLS Injector

The Linac Coherent Light Source (LCLS) is a SASE xray Free-Electron Laser (FEL) project presently under construction at SLAC. The injector section, from drive-laser and RF photocathode gun through first bunch compressor chicane, was installed in fall 2006. Initial system commissioning with an electron beam has recently been completed. The second phase of construction, including second bunch compressor and full linac, is planned for 2008. In this paper, we report experimental results and experience gained during the first phase of machine commissioning. This includes the cathode, drive laser, RF photocathode gun, linac booster section, S-band and X-band RF systems, first bunch compressor, and the various beam diagnostics.
Date: November 16, 2007
Creator: Dowell, D. H.; Akre, R.; Ding, Y.; Emma, P.; Frisch, J.; Gilevich, S. et al.
Object Type: Article
System: The UNT Digital Library
Evaluation of the Gas Production Potential of Marine HydrateDeposits in the Ulleung Basin of the Korean East Sea (open access)

Evaluation of the Gas Production Potential of Marine HydrateDeposits in the Ulleung Basin of the Korean East Sea

Although significant hydrate deposits are known to exist in the Ulleung Basin of the Korean East Sea, their survey and evaluation as a possible energy resource has not yet been completed. However, it is possible to develop preliminary estimates of their production potential based on the limited data that are currently available. These include the elevation and thickness of the Hydrate-Bearing Layer (HBL), the water depth, and the water temperature at the sea floor. Based on this information, we developed estimates of the local geothermal gradient that bracket its true value. Reasonable estimates of the initial pressure distribution in the HBL can be obtained because it follows closely the hydrostatic. Other critical information needs include the hydrate saturation, and the intrinsic permeabilities of the system formations. These are treated as variables, and sensitivity analysis provides an estimate of their effect on production. Based on the geology of similar deposits, it is unlikely that Ulleung Basin accumulations belong to Class 1 (involving a HBL underlain by a mobile gas zone). If Class 4 (disperse, low saturation accumulations) deposits are involved, they are not likely to have production potential. The most likely scenarios include Class 2 (HBL underlain by a zone of …
Date: November 16, 2007
Creator: Moridis, George J.; Reagan, Matthew T.; Kim, Se-Joon; Seol,Yongkoo & Zhang, Keni
Object Type: Article
System: The UNT Digital Library
Radiative Penguin Decays at the B Factories (open access)

Radiative Penguin Decays at the B Factories

In this article, I review the most recent results in radiative penguin decays from the B factories Belle and BABAR. Most notably, I will talk about the recent new observations in the decays B {yields} ({rho}/{omega}) {gamma}, a new analysis technique in b {yields} s{gamma}, and first measurements of radiative penguin decays in the B{sup 0}{sub s} meson system. Finally, I will summarize the current status and future prospects of radiative penguin B physics at the B factories.
Date: November 16, 2007
Creator: Koneke, Karsten
Object Type: Article
System: The UNT Digital Library
Extracting longitudinal shower developmentinformation from crystal calorimetry plus tracking (open access)

Extracting longitudinal shower developmentinformation from crystal calorimetry plus tracking

We propose a novel approach to derive longitudinal shower development information from a longitudinally unsegmented calorimeter such as the BaBar electromagnetic calorimeter by utilizing tracking information in conjunction with that of calorimetry. We show that using this information as part of an electron identification algorithm results in a significant reduction in the pion misidentification probability for low momentum particles. We also demonstrate how this information provides general charged particle separation at low momentum, particularly between pions and muons.
Date: November 16, 2007
Creator: Brown, D.N.; Ilic, J. & Mohanty, G.B.
Object Type: Article
System: The UNT Digital Library
A Simplistic View of Hadron Calorimetry (open access)

A Simplistic View of Hadron Calorimetry

All too often we rely on Monte Carlo simulations withoutworrying too much about basic physics. It is possible to start with avery simple calorimeter (a big cylinder) and learn the functional form ofpi e by aninduction argument. Monte Carlo simulations provide sanitychecks and constants. A power-law functional form describes test beamresults surprisingly well. The prediction that calorimeters responddifferently to protons and pions of the same energy was unexpected. Theeffect was later demonstrated by the CMS forward calorimeter group, usingthe most noncompensating calorimeter ever built. Calorimeter resolutionis dominated by fluctuations in piz production and the energy deposit byneutrons. The DREAM collaboration has recently used a dual readoutcalorimeter to eliminate the first of these. Ultimate resolution dependson measuring neutrons on an event-by-event basis as well.
Date: November 16, 2006
Creator: Groom, Donald E.
Object Type: Article
System: The UNT Digital Library
Annual Change Report 2006/2007 (open access)

Annual Change Report 2006/2007

As part of continuing compliance, the U.S. Environmental Protection Agency (EPA) requires the U.S. Department of Energy (DOE) to provide information on any change in conditions or activities pertaining to the disposal system since the most recent compliance application. This requirement is identified in Title 40 Code of Federal Regulations (CFR), Section 194.4(b)(4), which states: "No later than six months after the administrator issues a certification, and at least annually thereafter, the Department shall report to the Administrator, in writing, any changes in conditions or activities pertaining to the disposal system that were not required to be reported by paragraph (b)(3) of this section and that differ from information contained in the most recent compliance application." In meeting the requirement, the DOE provides an annual report each November of all applicable changes under the above requirement. This annual report informs the EPA of changes to information in the most recent compliance recertification (the 2004 Compliance Recertification). Significant planned changes must be reported to the EPA prior to implementation by the DOE. In addition, Title 40 CFR, Section 194.4(b)(3) requires that significant unplanned changes be reported to the EPA within 24 hours or ten days, depending on the severity of the …
Date: November 16, 2007
Creator: Washington Regulatory and Environmental Services
Object Type: Report
System: The UNT Digital Library
CORROSION OF LEAD SHIELDING IN NUCLEAR MATERIALS PACKAGES (open access)

CORROSION OF LEAD SHIELDING IN NUCLEAR MATERIALS PACKAGES

Inspection of United States-Department of Energy (US-DOE) model 9975 nuclear materials shipping package revealed corrosion of the lead shielding induced by off-gas constituents from organic components in the package. Experiments were performed to determine the corrosion rate of lead when exposed to off-gas or degradation products of these organic materials. The results showed that the room temperature vulcanizing (RTV) sealant was the most corrosive organic species followed by the polyvinyl acetate (PVAc) glue. The fiberboard material induced corrosion to a much lesser extent than the PVAc glue and RTV, and only in the presence of condensed water. The results indicated faster corrosion at temperatures higher than ambient and with condensed water as expected. A corrosion rate of 0.05 mm/year measured for coupons exposed to the most aggressive conditions was recommended as a conservative estimate for use in package performance calculations.
Date: November 16, 2007
Creator: Subramanian, K & Kerry Dunn, K
Object Type: Article
System: The UNT Digital Library
Symmetry reduction of (delta)-plutonium: an electronic-structure effect (open access)

Symmetry reduction of (delta)-plutonium: an electronic-structure effect

Using first-principles density-functional theory calculations, we show that the anomalously large anisotropy of {sigma}-plutonium is a consequence of greatly varying bond-strengths between the 12 nearest neighbors. Employing the calculated bond strengths, we expand the tenants of classical crystallography by incorporating anisotropy of chemical bonds, which yields a structure with the monoclinic space group Cm for {delta}-plutonium rather than face-centered cubic Fm{bar 3}m. The reduced space group for {delta}-plutonium enlightens why the ground state of the metal is monoclinic, why distortions of the metal are viable, and has considerable implications for the behavior of the material as it ages. These results illustrate how an expansion of classical crystallography that accounts for anisotropic electronic structure can explain complicated materials in a novel way.
Date: November 16, 2005
Creator: Moore, K; Soderlind, P; Schwartz, A & Laughlin, D
Object Type: Article
System: The UNT Digital Library
Timescales and settings for alteration of chondritic meteorites (open access)

Timescales and settings for alteration of chondritic meteorites

Most groups of chondritic meteorites experienced diverse styles of secondary alteration to various degrees that resulted in formation of hydrous and anhydrous minerals (e.g., phyllosilicates, magnetite, carbonates, ferrous olivine, hedenbergite, wollastonite, grossular, andradite, nepheline, sodalite, Fe,Ni-carbides, pentlandite, pyrrhotite, Ni-rich metal). Mineralogical, petrographic, and isotopic observations suggest that the alteration occurred in the presence of aqueous solutions under variable conditions (temperature, water/rock ratio, redox conditions, and fluid compositions) in an asteroidal setting, and, in many cases, was multistage. Although some alteration predated agglomeration of the final chondrite asteroidal bodies (i.e. was pre-accretionary), it seems highly unlikely that the alteration occurred in the solar nebula, nor in planetesimals of earlier generations. Short-lived isotope chronologies ({sup 26}Al-{sup 26}Mg, {sup 53}Mn-{sup 53}Cr, {sup 129}I-{sup 129}Xe) of the secondary minerals indicate that the alteration started within 1-2 Ma after formation of the Ca,Al-rich inclusions and lasted up to 15 Ma. These observations suggest that chondrite parent bodies must have accreted within the first 1-2 Ma after collapse of the protosolar molecular cloud and provide strong evidence for an early onset of aqueous activity on these bodies.
Date: November 16, 2005
Creator: Krot, A. N.; Hutcheon, I. D.; Brearley, A. J.; Pravdivtseva, O. V.; Petaev, M. I. & Hohenberg, C. M.
Object Type: Book
System: The UNT Digital Library
Relativistic Dark Matter at the Galactic Center (open access)

Relativistic Dark Matter at the Galactic Center

In a large region of the supersymmetry parameter space, the annihilation cross section for neutralino dark matter is strongly dependent on the relative velocity of the incoming particles. We explore the consequences of this velocity dependence in the context of indirect detection of dark matter from the galactic center. We find that the increase in the annihilation cross section at high velocities leads to a flattening of the halo density profile near the galactic center and an enhancement of the annihilation signal.
Date: November 16, 2007
Creator: Amin, Mustafa A.; /Stanford U., Phys. Dept. /KIPAC, Menlo Park & Wizansky, Tommer
Object Type: Article
System: The UNT Digital Library
Single-Mode VISAR (open access)

Single-Mode VISAR

High energy-density physics (HEDP) experiments examine the properties of materials under extreme conditions. These experiments rely on the measurement of one or two velocities. These velocities are used to obtain Hugoniot relationships and thermodynamic equations of state. This methodology is referred to as 'velocimetry' and an instrument used to measure the shock wave is called a 'velocimeter' or a '(velocity) diagnostic'. The two most-widely used existing velocity diagnostics are; photonic Doppler velocimetry (PDV) and velocity interferometer system for any reflector (VISAR). PDV's advantages are a fast rise-time and ease of implementation but PDV has an upper velocity limit. Traditional implementations of VISAR have a rise time 10 times slower than PDV and are not easily implemented but are capable of measuring any velocity produced during HEDP experiments. This thesis describes a novel method of combining the positive attributes of PDV and VISAR into a more cost effective diagnostic called a Single-Mode VISAR (SMV). The new diagnostic will consist of PDV parts in a VISAR configuration. This configuration will enable the measurement of any velocity produced during shock physics experiments while the components used to build the diagnostic will give the diagnostic a fast rise time and make it easy to …
Date: November 16, 2007
Creator: Krauter, K
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Possible Connection Between Dark Energy And the Hierarchy (open access)

A Possible Connection Between Dark Energy And the Hierarchy

Recently it was suggested that the dark energy maybe related to the well-known hierarchy between the Planck scale ({approx} 10{sup 19} GeV) and the TeV scale. The same brane-world setup to address this hierarchy problem may also in principle address the smallness problem of dark energy. Specifically, the Planck-SM hierarchy ratio was viewed as a quantum gravity-related, dimensionless fine structure constant where various physical energy scales in the system are associated with the Planck mass through different powers of the 'gravity fine structure constant'. In this paper we provide a toy model based on the Randall-Sundrum geometry where SUSY-breaking is induced by the coupling between a SUSY-breaking Higgs field on the brane and the KK gravitinos. We show that the associated Casimir energy density indeed conforms with the dark energy scale.
Date: November 16, 2007
Creator: Chen, Pisin; /SLAC /KIPAC, Menlo Park; Gu, Je-An & /NCTS, Hsinchu
Object Type: Article
System: The UNT Digital Library
n+-p ELASTIC SCATTERING AT 310 Mev: REC0IL-NUCLEONPOLARIZATION (open access)

n+-p ELASTIC SCATTERING AT 310 Mev: REC0IL-NUCLEONPOLARIZATION

The recoil-proton polarization in {pi}{sup +}-p elastic scattering at 310-Mev incident-pion laboratory kinetic energy has been experimentally measured at four scattering angles with scintillation counters. Polarization values obtained, related rms experimental errors, and mean center-of-mass recoil angles are: +0.044 {+-} 0.062 at 114.2 deg. =0.164 {+-} 0.057 at 124.5 deg, -0.155 {+-} 0.044 at 133.8 deg, and -0.162 {+-} 0.037 at 145.2 deg. The sign of the polarization is defined to be positive when a preponderance of the recoil protons had their spin vectors pointing in the direction of {rvec P}{sub i} x {rvec p}{sub f}, where this quantity is the cross product of the initial and final momentum vectors of the conjugate pions. A beam of 1 x 10{sup 6} pions per sec incident upon a 1.0-g/cm{sup 2}-thick liquid-hydrogen target produced the recoil protons, which were then scattered by a carbon target at a mean energy varying with recoil angle from 113 to 141 Mev. The polarization of the recoil protons was analyzed by measuring the asymmetry produced in the carbon scattering. A proton beam of known polarization was used to determine the analyzing ability (measured asymmetry divided by the polarization of the incident protons) of the system at …
Date: November 16, 1960
Creator: Foote, James H.; Chamberlain, Owen; Rogers, Ernest H.; Steiner,Herbert M.; Wiegand, Clyde E. & Ypsilantis, Thomas.
Object Type: Report
System: The UNT Digital Library
Field Investigation to Determine the Extent of Sediment Recontamination at the United Heckathorn Superfund Site, Richmond, California (open access)

Field Investigation to Determine the Extent of Sediment Recontamination at the United Heckathorn Superfund Site, Richmond, California

This field investigation was undertaken to determine the present condition of sediment in Lauritzen Channel and Parr Canal approximately 2 years after completion of sediment remedial actions at the United Heckathorn Superfund site. The study was designed to supplement the post-remediation monitoring program by determining the extent and identifying potential sources of observed pesticide contamination in marine sediments near the site. Core samples collected from Lauritzen Channel and Parr Canal in July 1999 were described geologically, and samples were prepared from different sediment types, such as younger bay mud or older bay mud. Sediment samples were analyzed for grain size, organic carbon, and DDT compounds. Only minor changes have occurred in Parr Canal since remedial actions were taken in 1996-1997, but in Lauritzen Channel, DDT concentrations exceed the remedial goal of 590 ug/kg dry weight in nearly all the unconsolidated sediment (younger bay mud, sand, and disturbed older bay mud). The source of contaminated sediment could not be confirmed by this study; there was no clear correlation between high DDT concentrations and sediment remaining between the pilings, as was originally suspected. There also was no correlation between high DDT concentrations in sediment and the locations of outfalls, although some of …
Date: November 16, 2001
Creator: Kohn, Nancy P. & Gilmore, Tyler J.
Object Type: Report
System: The UNT Digital Library