Online modeling of the Fermilab accelerators (open access)

Online modeling of the Fermilab accelerators

Access through the Fermilab control system to beam physics models of the Fermilab accelerators has been implemented. The models run on Unix workstations, communicating with legacy VMS-based controls consoles via a relational database and TCP/IP.The client side (VMS) and the server side (Unix) are both implemented in object-oriented C++. The models allow scientists and operators in the control room to do beam physics calculations. Settings of real devices as input to the model are supported, and readings from beam diagnostics may be compared with model predictions.
Date: November 22, 1999
Creator: E. McCrory, O. Krivosheev, L. Michelotti and J-F. Ostiguy
Object Type: Article
System: The UNT Digital Library
Buoyancy and Dissolution of the Floating Crust Layer in Tank 241-SY-101 During Transfer and Back-Dilution (open access)

Buoyancy and Dissolution of the Floating Crust Layer in Tank 241-SY-101 During Transfer and Back-Dilution

To remediate gas retention in the floating crust layer and the potential for buoyant displacement gas releases from below the crust, waste will be transferred out of Hanford Tank 241-SY-101 (SY-101) in the fall of 1999 and back-diluted with water in several steps of about 100,000 gallons each. To evaluate the effects of back-dilution on the crust a static buoyancy model is derived that predicts crust and liquid surface elevations as a function of mixing efficiency and volume of water added during transfer and back-dilution. Experimental results are presented that demonstrate the basic physics involved and verify the operation of the models. A dissolution model is also developed to evaluate the effects of dissolution of solids on crust flotation. The model includes dissolution of solids suspended in the slurry as well as in the crust layers. The inventory and location of insoluble solids after dissolution of the soluble fraction are also tracked. The buoyancy model is applied to predict the crust behavior for the first back-dilution step in SY-101. Specific concerns addressed include conditions that could cause the crust to sink and back-dilution requirements that keep the base of the crust well above the mixer pump inlet.
Date: November 22, 1999
Creator: Stewart, C. W.; Sukamto, J. H.; Cuta, J. M. & Rassat, S. D.
Object Type: Report
System: The UNT Digital Library
Pulsed Power Driven Fusion Energy (open access)

Pulsed Power Driven Fusion Energy

Pulsed power is a robust and inexpensive technology for obtaining high powers. Considerable progress has been made on developing light ion beams as a means of transporting this power to inertial fusion capsules. However, further progress is hampered by the lack of an adequate ion source. Alternatively, z-pinches can efficiently convert pulsed power into thermal radiation, which can be used to drive an inertial fusion capsule. However, a z-pinch driven fusion explosion will destroy a portion of the transmission line that delivers the electrical power to the z-pinch. They investigate several options for providing standoff for z-pinch driven fusion. Recyclable Transmission Lines (RTLs) appear to be the most promising approach.
Date: November 22, 1999
Creator: SLUTZ,STEPHEN A.
Object Type: Article
System: The UNT Digital Library
Supersymmetry searches at the Tevatron in Run I and Run II (open access)

Supersymmetry searches at the Tevatron in Run I and Run II

The authors review the searches for supersymmetric particles achieved by the CDF and D0 collaborations at the p{bar p} Tevatron collider at FNAL, at {radical}s = 1.8 TeV and with a total integrated luminosity of 110 pb{sup {minus}1}, per experiment. The prospects for the forthcoming run at {radical}s = 2 TeV and an integrated luminosity reaching ultimately at least 20 fb{sup {minus}1}, are also discussed.
Date: November 22, 1999
Creator: Savoy-Navarro, A.
Object Type: Article
System: The UNT Digital Library
Processing and characterization of high porosity aerogel films (open access)

Processing and characterization of high porosity aerogel films

Aerogels are highly porous solids having unique morphology among materials because both the pores and particles making up the material have sizes less than wavelengths of visible light. Such a unique morphology modifies the normal molecular transport mechanisms within the material, resulting in exceptional thermal, acoustical, mechanical, and electrical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. Special methods are required to make aerogel films with high porosity. In this paper, we discuss the special conditions needed to fabricate aerogel films having porosities greater than 75% and we describe methods of processing inorganic aerogel films having controllable thicknesses in the range 0.5 to 200 micrometers. We report methods and results of characterizing the films including thickness, refractive index, density (porosity), and dielectric constant. We also discuss results of metallization and patterning on the aerogel films for applications involving microminiature electronics and thermal detectors.
Date: November 22, 1994
Creator: Hrubesh, L. W. & Poco, J. F.
Object Type: Article
System: The UNT Digital Library
The Intermediate Silicon Layers (ISL) Detector for the Collider Detector at Fermilab (open access)

The Intermediate Silicon Layers (ISL) Detector for the Collider Detector at Fermilab

The Intermediate Silicon Layers detector is part of the CDF upgrade for Run II. The ISL is a large radius (29 cm) silicon tracker with a total active area of about 3.5 m{sup 2}. The conceptual design and the status of the project are reviewed.
Date: November 22, 1999
Creator: Leone, Sandra
Object Type: Article
System: The UNT Digital Library
Conceptual design of a common coil dipole for VLHC (open access)

Conceptual design of a common coil dipole for VLHC

Superconducting magnet technology and cost reduction are key issues in the R and D effort towards a post-LHC, 100 TeV hadron collider. A dipole field of 10-12 T at 4.5 K operating temperature results in acceptable machine length and refrigeration power requirements, and allows taking advantage of synchrotron radiation damping to achieve low beam emittance. In this paper, the conceptual design of a react-and-wind common coil dipole is presented, which aims at these operating parameters with minimum cost and complexity.
Date: November 22, 1999
Creator: Sabbi, G.; Ambrosio, G.; Andreev, N.; Barzi, E.; Ewald, K.; Limon, P. et al.
Object Type: Article
System: The UNT Digital Library
Rapid Bioassessment Methods for Assessing Stream Macroinvertebrate Community on the Savannah River Site (open access)

Rapid Bioassessment Methods for Assessing Stream Macroinvertebrate Community on the Savannah River Site

Macroinvertebrate sampling was performed at 16 locations in the Savannah River Site (SRS) streams using Hester-Dendy multiplate samplers and EPA Rapid Bioassessment Protocols (RBP). Some of the sampling locations were unimpacted, while other locations had been subject to various forms of perturbation by SRS activities. In general, the data from the Hester-Dendy multiplate samplers were more sensitive at detecting impacts than were the RBP data. We developed a Biotic Index for the Hester-Dendy data which incorporated eight community structure, function, and balance parameters. when tested using a data set that was unrelated to the data set that was used in developing the Biotic Index, the index was very successful at detecting impact.
Date: November 22, 1999
Creator: Specht, Winona L.
Object Type: Report
System: The UNT Digital Library
Experimental status of b hadron lifetimes (open access)

Experimental status of b hadron lifetimes

In this paper the authors review the most recent experimental results on the various B hadron species lifetimes obtained at electron-positron machines and at the Tevatron.
Date: November 22, 1999
Creator: Donati, S.
Object Type: Article
System: The UNT Digital Library
An induction Linac approach to phase rotation of a muon bunch in the production region of {mu}{sup +}-{mu}{sup {minus}} colliders (open access)

An induction Linac approach to phase rotation of a muon bunch in the production region of {mu}{sup +}-{mu}{sup {minus}} colliders

The possibility of using an induction linac for phase rotation, or equivalently flattening the head to tail mean energy sweep, of a muon bunch in the production region of a {mu}{sup +} {minus} {mu}{sup {minus}} is examined. Axial spreading of an accelerating bunch is analyzed and the form of appropriate induction cell voltage waveforms is derived. A set of parametric equations for the induction accelerator structure is given and specific solutions are presented which demonstrate the technological feasibility of the induction linac approach to phase rotation.
Date: November 22, 1995
Creator: Turner, W.C.
Object Type: Article
System: The UNT Digital Library
Supersymmetry at LHC (open access)

Supersymmetry at LHC

Supersymmetry (SUSY) is an appealing concept which provides a plausible solution to the fine tuning problem, while leaving the phenomenological success of the Standard Model (SM) unchanged. Moreover, some SUSY models allow for the unification of gauge couplings at a scale of M{sub GUT} {approx} 10{sup 16} GeV. A further attractive feature is the possibility of radiative breaking of the electro-weak symmetry group SU(2) {times} U(1). The masses of the SUSY partners of the SM particles are expected to be in the range 100 GeV to 1 TeV. One of the main goals of the Large Hadron Collider (LHC) will be either to discover weak-scale SUSY or to exclude it over the entire theoretically allowed parameter space. The authors have developed a strategy for the analysis of experimental data at LHC which will allow them to determine the scale for supersymmetry, to limit the model parameter space, and to make precision measurements of model parameters.
Date: November 22, 1996
Creator: Bartl, A.; Soederqvist, J. & Paige, F.
Object Type: Report
System: The UNT Digital Library
Signals from flavor changing scalar currents at the future colliders (open access)

Signals from flavor changing scalar currents at the future colliders

We present a general phenomenological analysis of a class of Two Higgs Doublet Models with Flavor Changing Neutral Currents arising at the tree level. The existing constraints mainly affect the couplings of the first two generations of quarks, leaving the possibility for non negligible Flavor Changing couplings of the top quark open. The next generation of lepton and hadron colliders will offer the right environment to study the physics of the top quark and to unravel the presence of new physics beyond the Standard Model. In this context we discuss some interesting signals from Flavor Changing Scalar Neutral Currents.
Date: November 22, 1996
Creator: Atwood, D.; Reina, L. & Soni, A.
Object Type: Article
System: The UNT Digital Library
3D Mesh optimization methods for unstructured polyhedra: A progress report (open access)

3D Mesh optimization methods for unstructured polyhedra: A progress report

A mesh optimization scheme allows a Lagrangian code to run problems with extreme mesh distortion by reconfiguring node and zone connectivity as the problem evolves. We have developed some 3D mesh optimization operations and criteria for applying them. These are demonstrated in a 3D Free Lagrange code being developed at LLNL. In the simplest case of a mesh or mesh subregion composed purely of tetrahedra we can maintain a Delaunay tetrahedralization. For more interesting meshes, made up of general polyhedra, a suite of optimization operations and their respective application criteria have been developed.
Date: November 22, 1994
Creator: Miller, D. S. & Burton, D. E.
Object Type: Article
System: The UNT Digital Library
A proposal for a Los Alamos international facility for transmutations (LIFT) (open access)

A proposal for a Los Alamos international facility for transmutations (LIFT)

The major groups engaged in transmutation research are converging towards a common objective and similar technology. It is now possible to envision an international program of research aimed at the destruction of reactor-generated (and other) nuclear waste using a series of multipurpose experimental facilities in the near future. Los Alamos National Laboratory, as the home of the highest power LINAC and a very active transmutation technology project, is the ideal host for the first of such facilities. The next step in the international program (a facility 10 times more powerful, for engineering-scale demonstrations) could be built in Europe, where there is substantial interest in the construction of such a device in the framework of international cooperation. A series of experiments at Las Alamos could explore the key transmutation technologies. Liquid lead loops, a liquid lead spallation target, and a large size liquid lead facility with provision for irradiation, cooling and diagnostics of several types of `transmutation assemblies`, where different transmutation concepts will be tested in different media and environments, from transmutation of fission products to destruction by fission of higher actinides, to other waste management applications. The engineering-scale facility, which will follow the initial testing phase, will extend the best …
Date: November 22, 1996
Creator: Venneri, F.; Williamson, M. A.; Li, Ning & Doolen, G.
Object Type: Report
System: The UNT Digital Library
Probing quartic couplings through three gauge boson production at an e{sup +}e{sup {minus}} linear collider (open access)

Probing quartic couplings through three gauge boson production at an e{sup +}e{sup {minus}} linear collider

We explore the capability of a 500 or 1000 GeV e{sup +} e{sup {minus}} linear collider to measure anomalous quartic gauge boson couplings. In the framework of a non-linear effective Lagrangian with a custodial SU(2) symmetry, there are only two next-to-leading order operators which contribute to quartic, but not to two- and three-gauge boson interactions. The limits on the coefficients of these operators from present and future e{sup +} e{sup {minus}} colliders are compared with those available from other sources.
Date: November 22, 1996
Creator: Dawson, S.; Likhoded, A.; Valencia, G. & Yushchenko, O.
Object Type: Article
System: The UNT Digital Library
CNI polarimetry and the hadronic spin dependence of pp scattering (open access)

CNI polarimetry and the hadronic spin dependence of pp scattering

Methods for limiting the size of hadronic spin-flip in the Coulomb- Nuclear Interference. region are critically assessed. This work was presented at the High Energy Polarimetry Workshop in Amsterdam, Sept. 9, 1996 and the RHIC Spin Collaboration meeting in Marseille, Sept. 17, 1996.
Date: November 22, 1996
Creator: Trueman, T. L.
Object Type: Article
System: The UNT Digital Library
TART97 a coupled neutron-photon 3-D, combinatorial geometry Monte Carlo transport code (open access)

TART97 a coupled neutron-photon 3-D, combinatorial geometry Monte Carlo transport code

TART97 is a coupled neutron-photon, 3 Dimensional, combinatorial geometry, time dependent Monte Carlo transport code. This code can on any modern computer. It is a complete system to assist you with input preparation, running Monte Carlo calculations, and analysis of output results. TART97 is also incredibly FAST; if you have used similar codes, you will be amazed at how fast this code is compared to other similar codes. Use of the entire system can save you a great deal of time and energy. TART97 is distributed on CD. This CD contains on- line documentation for all codes included in the system, the codes configured to run on a variety of computers, and many example problems that you can use to familiarize yourself with the system. TART97 completely supersedes all older versions of TART, and it is strongly recommended that users only use the most recent version of TART97 and its data riles.
Date: November 22, 1997
Creator: Cullen, D.E.
Object Type: Report
System: The UNT Digital Library
Design of a new liquid cell for shock experiments (open access)

Design of a new liquid cell for shock experiments

Controlled impact methodology has been used on a powdergun to obtain dynamic behavior properties of Tributyl Phosphate (TBP). A novel test methodology is used to provide extremely accurate equation of state data of the liquid. A thin aluminum plate used for confining the liquid also serves as a diagnostic to provide reshock states and subsequent release adiabats from the reshocked state. Polar polymer, polyvinylidene fluoride (PVDF) gauges and velocity interferometer system for any reflector (VISAR) provided redundant and precise data of temporal resolution to five nanoseconds and shock velocity measurements of better than 1%. The design and test methodologies are presented in this paper.
Date: November 22, 1999
Creator: Reinhart, W. D. & Chhabildas, L. C.
Object Type: Article
System: The UNT Digital Library
Assessing the disposal of wastes containing NORM in nonhazardous waste landfills (open access)

Assessing the disposal of wastes containing NORM in nonhazardous waste landfills

In the past few years, many states have established specific regulations for the management of petroleum industry wastes containing naturally occurring radioactive material (NORM) above specified thresholds. These regulations have limited the number of disposal options available for NORM-containing wastes, thereby increasing the related waste management costs. In view of the increasing economic burden associated with NORM management, industry and regulators are interested in identifying cost-effective disposal alternatives that still provide adequate protection of human health and the environment. One such alternative being considered is the disposal of NORM-containing wastes in landfills permitted to accept only nonhazardous wastes. The disposal of petroleum industry wastes containing radium-226 and lead-210 above regulated levels in nonhazardous landfills was modeled to evaluate the potential radiological doses and associated health risks to workers and the general public. A variety of scenarios were considered to evaluate the effects associated with the operational phase (i.e., during landfill operations) and future use of the landfill property. Doses were calculated for the maximally exposed receptor for each scenario. This paper presents the results of that study and some conclusions and recommendations drawn from it.
Date: November 22, 1999
Creator: Smith, K. P.; Blunt, D. L.; Williams, G. P.; Arnish, J. J.; Pfingston, M. R. & Herbert, J.
Object Type: Article
System: The UNT Digital Library
Absolute CH radical concentrations in rich low-pressure methane-oxygen-argon flames via cavity ringdown spectroscopy of the A transition (open access)

Absolute CH radical concentrations in rich low-pressure methane-oxygen-argon flames via cavity ringdown spectroscopy of the A transition

We measure cavity ringdown spectra of the A{sup 2}{Delta}-X{sup 2}II transition of the methylidyne (CH) radical in a series of rich low-pressure methane-oxygen-argon flames and demonstrate that the technique is sensitive, quantitative, and straightforward in its implementation and interpretation. As a line-of-sight technique, it complements imaging techniques, such as planar laser-induced fluorescence. Our results generally agree with chemical kinetic models for methane oxidation that have appeared in the literature, but suggest some refinements are necessary. Additional examination of the CH + O{sub 2} reaction rate as a function of temperature is advised. Our results are consistent with those of Derzy et al. using the C{sup 2}{Sigma}{sup +}-X{sup 2}II transition for stoichiometric, low-pressure flames which include nitrogen. Our results for rich flames, as with earlier experiments for singlet methylene, suggest that flame chemical kinetic models need to be adjusted to account for flame chemistry for stoichiometries richer than {phi} = 1.5.
Date: November 22, 1999
Creator: John W. Thomas, Jr & McIlroy, Andrew
Object Type: Article
System: The UNT Digital Library
X-ray interferometry development at the Advanced Photon Source. (open access)

X-ray interferometry development at the Advanced Photon Source.

In this paper, we report initial test results of a four-bounce Bragg reflection X-ray interferometer at 7.46 keV and, for the first time to our knowledge, at the higher energy of 14.91 keV where the spectral acceptance is much smaller.
Date: November 22, 1999
Creator: Fezzaa, K. & Lee, W. K.
Object Type: Article
System: The UNT Digital Library
Buildings for the 21st Century Newsletter: Fall 1999, Vol. 2, No. 1 (open access)

Buildings for the 21st Century Newsletter: Fall 1999, Vol. 2, No. 1

This edition contains more information about new efforts and programs in DOE's Office of Building Technology, State and Community Programs (BTS), and highlights the evolution of a new approach to making buildings more energy-efficient, comfortable, and affordable.
Date: November 22, 1999
Creator: National Renewable Energy Laboratory (U.S.)
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
A simple way of characterizing x-ray downwards-deflecting mirror-bender assemblies using the long trace profiler (open access)

A simple way of characterizing x-ray downwards-deflecting mirror-bender assemblies using the long trace profiler

A simple device composed of a modular double-pentaprism system that enables the long trace profiler (LTP) to measure mirrors in nonconventional ways, i.e., in the vertical-downward and sideways positions, has been devised and implemented in the Advanced Photon Source (APS) long trace profiler (LTP II). The systems is very useful in calibrating mirror-bender assemblies. This paper describes the system and gives results of measurements performed with it on a mirror used at the APS.
Date: November 22, 1999
Creator: Assoufid, L. & Her, P.
Object Type: Article
System: The UNT Digital Library
Pressure Effects Analysis of National Ignition Facility Capacitor Module Events (open access)

Pressure Effects Analysis of National Ignition Facility Capacitor Module Events

Capacitors and power conditioning systems required for the National Ignition Facility (NIF) have experienced several catastrophic failures during prototype demonstration. These events generally resulted in explosion, generating a dramatic fireball and energetic shrapnel, and thus may present a threat to the walls of the capacitor bay that houses the capacitor modules. The purpose of this paper is to evaluate the ability of the capacitor bay walls to withstand the overpressure generated by the aforementioned events. Two calculations are described in this paper. The first one was used to estimate the energy release during a fireball event and the second one was used to estimate the pressure in a capacitor module during a capacitor explosion event. Both results were then used to estimate the subsequent overpressure in the capacitor bay where these events occurred. The analysis showed that the expected capacitor bay overpressure was less than the pressure tolerance of the walls. To understand the risk of the above events in NIF, capacitor module failure probabilities were also calculated. This paper concludes with estimates of the probability of single module failure and multi-module failures based on the number of catastrophic failures in the prototype demonstration facility.
Date: November 22, 1999
Creator: Brereton, S; Ma, C; Newton, M; Pastrnak, J; Price, D & Prokosch, D
Object Type: Article
System: The UNT Digital Library