B production in hadron collisions: Theory (open access)

B production in hadron collisions: Theory

A review is presented of heavy quark production in {bar p}p, {pi}{sup -}p, and pp interactions at fixed target and collider energies. Calculations of total cross sections and of single quark inclusive differential cross sections d{sup 2}{sigma}/dk{sub T}dy are described including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of the charm and bottom quark masses and other parameters. Predictions and open issues in the interpretation of results are summarized. 20 refs., 5 figs.
Date: September 28, 1989
Creator: Berger, E. L.
Object Type: Article
System: The UNT Digital Library
Prospects for a soft x-ray FEL powered by a relativistic-klystron high-gradient accelerator (RK-HGA) (open access)

Prospects for a soft x-ray FEL powered by a relativistic-klystron high-gradient accelerator (RK-HGA)

We present here the concept of x-ray FELs using high gain, single-pass amplifiers with electron beams accelerated in high gradient structures powered by relativistic klystrons. Other authors have also considered x-ray FELs; the unique aspect of this paper is the use of high gradient acceleration. One of the authors has previously presented preliminary studies on this concept. The intent in this paper is to display the results of a top level design study on a high gain FEL, to present its sensitivity to a variety of fabrication and tuning errors, to discuss several mechanisms for increasing gain yet more, and to present explicitly the output characteristics of such an FEL. The philosophy of the design study is to find a plausible operating point which employs existing or nearly existing state-of-the-art technologies while minimizing the accelerator and wiggler lengths. The notion is to distribute the technical risk as evenly as possible over the several technologies so that each must advance only slightly in order to make this design feasible. This study entailed no systematic investigation of possible costs so that, for example, the sole criterion for balancing the trade-off between beam energy and wiggler length is that the two components have …
Date: September 28, 1989
Creator: Shay, H. D.; Barletta, W. A.; Yu, S. S.; Schlueter, R. & Deis, G. A.
Object Type: Article
System: The UNT Digital Library
Beam dynamics in the Advanced Test Accelerator (ATA) (open access)

Beam dynamics in the Advanced Test Accelerator (ATA)

We will review the performance of the Advanced Test Accelerator, a 50 MeV, 10 KA induction linac. The discussion will cover the operation of the plasma cathode electron source, beam transport throughout the accelerator, and transverse instabilities. Particular emphasis will be placed on the beam breakup instability and on the methods used to minimize it. These include a program of design changes that lead to an order of magnitude reduction in the Q's of the accelerator cavity modes and optimization of the transport tune.
Date: September 28, 1983
Creator: Caporaso, G. J.; Barletta, W. A.; Birx, D. L.; Briggs, R. J.; Chong, Y. P.; Cole, A. G. et al.
Object Type: Article
System: The UNT Digital Library
Using the Nova target chamber for high-yield targets (open access)

Using the Nova target chamber for high-yield targets

The existing 2.2-m-radius Nova aluminum target chamber, coated and lined with boron-seeded carbon shields, is proposed for use with 1000-MJ-yield targets in the next laser facility. The laser beam and diagnostic holes in the target chamber are left open and the desired 10/sup -2/ Torr vacuum is maintained both inside and outside the target chamber; a larger target chamber room is the vacuum barrier to the atmosphere. The hole area available is three times that necessary to maintain a maximum fluence below 12 J/cm/sup 2/ on optics placed at a radius of 10 m. Maximum stress in the target chamber wall is 73 MPa, which complies with the intent of the ASME Pressure Vessel Code. However, shock waves passing through the inner carbon shield could cause it to comminute. We propose tests and analyses to ensure that the inner carbon shield survives the environment. 13 refs.
Date: September 28, 1987
Creator: Pitts, J.H.
Object Type: Article
System: The UNT Digital Library
Nitrogen oxide abatement by distributed fuel addition (open access)

Nitrogen oxide abatement by distributed fuel addition

A screening study was performed on a laboratory scale downfired combustor to determine the effect of various variables on the effectiveness of the reburning process as a technique for NO{sub x} abatement. The objective was to define optimum conditions under which reburning can be used and to be able to compare the reburning performance of our combustor to that reported by others. For this purpose, a statistically designed parametric investigation was conducted to determine how a set of controlled variables (primary and secondary stoichiometric ratios, location of the reburn zone and primary fuel load) would affect the reduction in NO emissions in a classical reburning configuration. Also, the effects of other variables (NO in the primary zone, temperatures in the primary, reburn and burnout zones and the residence time in the reburn zone) were also investigated. No optimum configuration was identified in this study. Nevertheless, this study provides insight into the parameters associated with reburning.
Date: September 28, 1988
Creator: Wendt, J.O.L. & Meraab, J.
Object Type: Report
System: The UNT Digital Library
Thermal stress in the edge cladding of Nova glass laser disks (open access)

Thermal stress in the edge cladding of Nova glass laser disks

We calculated thermal stresses in Nova glass laser disks having light-absorbing edge cladding glass attached to the periphery with an epoxy adhesive. Our closed-form solutions indicated that, because the epoxy adhesive is only 25 ..mu..m across, it does not significantly affect the thermal stress in the disk or cladding glass. Our numerical results showed a peak tensile stress in the cladding glass of 24 MPa when the cladding glass had a uniform absorption coefficient of 7.5 cm/sup -1/. This peak value is reduced to 19 MPa if surface parasitic oscillation heating is eliminated by tilting the disk edges. The peak tensile stresses exceed the typical 7 to 14-MPa working stress for glass; however, we have not observed any disk or cladding glass failures at peak Nova fluences of 20 J/cm/sup 2/. We have observed delamination of the epoxy adhesive bond at fluences several times that which would occur on Nova. Replacement laser disks will incorporate cladding with a reduced absorption coefficient of 4.5 cm/sup -1/. Recent experiments show that this reduced absorption coefficient is satisfactory.
Date: September 28, 1987
Creator: Pitts, J. H.; Kong, M. K. & Gerhard, M. A.
Object Type: Article
System: The UNT Digital Library
Neutron cross sections and Doppler effect of the 1. 056 eV resonance in /sup 240/Pu (open access)

Neutron cross sections and Doppler effect of the 1. 056 eV resonance in /sup 240/Pu

/sup 240/Pu possesses a value for the dilute resonance capture integral that is mostly due to the resonance at 1.056 eV. It is important to the neutron economy of a reactor to know the accurate size of the resonance, i.e., GAMMA/sub n/ and GAMMA/sub ..gamma../. The HFBR fast chopper facility has been used to make a determination of these resonance parameters. In this low energy region the intensity and resolution of the instrument are adequate for precise measurements.
Date: September 28, 1981
Creator: Liou, H. I. & Chrien, R. E.
Object Type: Article
System: The UNT Digital Library
Microwave Tokamak Experiment: An overview of the construction and checkout phase (open access)

Microwave Tokamak Experiment: An overview of the construction and checkout phase

At Lawrence Livermore National Laboratory (LLNL) we constructed and presently operate the Microwave Tokamak Experiment (MTX) to demonstrate the feasibility of using microwave pulses produced from a free electron laser (FEL) to provide electron cyclotron heating (ECH) for use in tokamaks, particularly high-field machines. The MTX consists primarily of the ALCATOR C tokamak and power supplies that were documented and disassembled at the Massachusetts Institute of Technology (MIT) and shipped to LLNL in April 1987. We made many additions, including a new primary power system from the magnetic Fusion Test Facility (MFTF) substation, a new commutation system, substantially upgraded seismic support system for earthquake loading, a fast controls system for use with the FEL, a new data-acquisition system, and a new vault facility. We checked out these systems and put them into operation in October 1988; we achieved the first plasma in November 1988. We have also constructed and installed the microwave transmission system and the local microwave system to be used with the FEL. These systems transmit the microwaves to MTX quasi-optically through an evacuated tube. The ongoing plasma operations, both with and without FEL heating, are described in a companion paper. 12 refs., 2 figs., 2 tabs.
Date: September 28, 1989
Creator: Lang, L. L. & Bell, H. H.
Object Type: Article
System: The UNT Digital Library
NK Muon Beam (open access)

NK Muon Beam

The NK Muon Beam will be a modified version of the existing NT beam line. The decision to employ a modified version of the NT beam line was made based on considerations of cost and availability of the beam line. Preliminary studies considered use of other beam lines, e.g., the NW beam line, and even of moving the bubble chamber with its superconducting coils but were rejected for reasons such as cost, personnel limitations, and potential conflicts with other users.
Date: September 28, 1988
Creator: Koizumi, G.
Object Type: Report
System: The UNT Digital Library
Characterization of organics in the feed streams for the H/F Effluent Treatment Facility (open access)

Characterization of organics in the feed streams for the H/F Effluent Treatment Facility

Analysis of weekly samples from the F- and H-area treblers indicates that tri-n-butylphosphate (TBP) is the major organic species in the feed to the F/H Effluent Treatment Facility (ETF). Concentrations up to 100 mg/L were observed, with an average of 50 mg/L from F-area and 3 mg/L from H-area. Normal paraffinic hydrocarbons (NPH) are present in lesser amounts, ranging up to 4 mg/L. These two species, both foulants of the reverse osmosis (RO) membranes, account for almost all of the dissolved organic carbon present in the samples. Samples from the sources which feed the treblers (and will feed the ETF) indicate that all eight canyon evaporators contribute TBP. None of the four tank farm evaporators contribute TBP. If TBP is to be removed at the sources, either the overhead streams from a number of evaporators will have to be piped to one or two central locations for treatment, or up to eight individual treatment points would have to be maintained. 6 refs., 5 tabs.
Date: September 28, 1987
Creator: Oblath, S. B.
Object Type: Report
System: The UNT Digital Library
Mechanical and hydraulic snubbers for nuclear applications, September 1984 (open access)

Mechanical and hydraulic snubbers for nuclear applications, September 1984

This standard covers the material, design, analysis, application, fabrication, testing, examination, quality assurance, certification, delivery, installation and inservice inspection of safety-related hydraulic and mechanical shock suppressors (snubbers) for nuclear reactors. These devices permit thermal expansion motion of components during normal plant service, but provide restraint to dynamic loads.
Date: September 28, 1984
Creator: unknown
Object Type: Report
System: The UNT Digital Library
International safeguards: Accounting for nuclear materials (open access)

International safeguards: Accounting for nuclear materials

Nuclear safeguards applied by the International Atomic Energy Agency (IAEA) are one element of the non-proliferation regime'', the collection of measures whose aim is to forestall the spread of nuclear weapons to countries that do not already possess them. Safeguards verifications provide evidence that nuclear materials in peaceful use for nuclear-power production are properly accounted for. Though carried out in cooperation with nuclear facility operators, the verifications can provide assurance because they are designed with the capability to detect diversion, should it occur. Traditional safeguards verification measures conducted by inspectors of the IAEA include book auditing; counting and identifying containers of nuclear material; measuring nuclear material; photographic and video surveillance; and sealing. Novel approaches to achieve greater efficiency and effectiveness in safeguards verifications are under investigation as the number and complexity of nuclear facilities grow. These include the zone approach, which entails carrying out verifications for groups of facilities collectively, and randomization approach, which entails carrying out entire inspection visits some fraction of the time on a random basis. Both approaches show promise in particular situations, but, like traditional measures, must be tested to ensure their practical utility. These approaches are covered on this report. 15 refs., 16 figs., 3 …
Date: September 28, 1988
Creator: Fishbone, L.G.
Object Type: Report
System: The UNT Digital Library
Nitrogen oxide abatement by distributed fuel addition. Quarterly report No. 4, May 1, 1988--July 30, 1988 (open access)

Nitrogen oxide abatement by distributed fuel addition. Quarterly report No. 4, May 1, 1988--July 30, 1988

A screening study was performed on a laboratory scale downfired combustor to determine the effect of various variables on the effectiveness of the reburning process as a technique for NO{sub x} abatement. The objective was to define optimum conditions under which reburning can be used and to be able to compare the reburning performance of our combustor to that reported by others. For this purpose, a statistically designed parametric investigation was conducted to determine how a set of controlled variables (primary and secondary stoichiometric ratios, location of the reburn zone and primary fuel load) would affect the reduction in NO emissions in a classical reburning configuration. Also, the effects of other variables (NO in the primary zone, temperatures in the primary, reburn and burnout zones and the residence time in the reburn zone) were also investigated. No optimum configuration was identified in this study. Nevertheless, this study provides insight into the parameters associated with reburning.
Date: September 28, 1988
Creator: Wendt, J. O. L. & Meraab, J.
Object Type: Report
System: The UNT Digital Library
Nuclear materials transportation workshops: USDOE outreach to local governments. Final report (open access)

Nuclear materials transportation workshops: USDOE outreach to local governments. Final report

To provide direct outreach to local governments, the Transportation Management Division of the United States Department of Energy asked the Urban Consortium and its Energy Task Force to assemble representatives for two workshops focusing on the transport of nuclear materials. The first session, for jurisdictions east of the Mississippi River, was held in New Orleans on May 5--6, 1988; the second was conducted on June 6--7, 1988 in Denver for jurisdictions to the west. Twenty local government professionals with management or operational responsibility for hazardous materials transportation within their jurisdictions were selected to attend each workshop. The discussions identified five major areas of concern to local government professionals; coordination; training; information resources; marking and placarding; and responder resources. Integrated federal, state, and local levels of government emerged as a priority coordination issue along with the need for expanded availability of training and training resources for first-reponders.
Date: September 28, 1987
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Progress toward high-gain laser fusion (open access)

Progress toward high-gain laser fusion

A 1985-1986 Review of the US inertial confinement fusion program by the National Academy of Sciences concluded that five more years might be required to obtain enough data to determine the future course of the program. Since then, data from the Nova laser and from the Halite/Centurion program have resolved most of the outstanding problems identified by the NAS review. In particular, we now believe that we can produce a sufficiently uniform target; that we can keep the energy content in hot electrons and high-energy photons low enough (/approximately/1--10% of drive energy, depending on target design) and achieve enough pulse-shaping accuracy (/approximately/10%, with a dynamic range of 100:1) to keep the fuel on a near-Fermi-degenerate adiabat; that we can produce an /approximately/100-Mbar pressure pulse of sufficient uniformity (/approximately/1%), and can we control hydrodynamic instabilities so that the mix of the pusher into the hot spot is low enough to permit marginal ignition. These results are sufficiently encouraging that the US Department of Energy is planning to complete a 10-MJ laboratory microfusion facility to demonstrate high-gain ICF in the laboratory within a decade. 22 refs., 1 fig.
Date: September 28, 1988
Creator: Storm, E.
Object Type: Article
System: The UNT Digital Library
Production of glass balloons for laser targets (open access)

Production of glass balloons for laser targets

An apparatus for producing small quantities of glass balloons for use as laser fusion targets is described. To produce precise quantities of the ingredients of one glass balloon, a jet of an aqueous solution of the glass constituents and a blowing agent is metered into uniformly sized drops by Rayleigh breakup. A small fraction of these uniform drops is then passed through an oven where the water is evaporated, the remaining solid material is fused into glass, and a blowing agent decomposes or water of hydration evolves as a vapor to blow the drop into a balloon. Photographs of the resulting glass balloons are presented.
Date: September 28, 1982
Creator: Hendricks, C.D. & Dressler, J.L.
Object Type: Article
System: The UNT Digital Library
Plasma potential formation and measurement in TMX-U and MFTF-B (open access)

Plasma potential formation and measurement in TMX-U and MFTF-B

Tandem mirrors control the axial variation of the plasma potential to create electrostatic plugs that improve the axial confinement of central cell ions and, in a thermal barrier tandem mirror, control the electron axial heat flow. Measurements of the spatial and temporal variations of the plasma potential are, therefore, important to the understanding of confinement in a tandem mirror. In this paper we discuss potential formation in a thermal barrier tandem mirror and examine the diagnostics and data obtained on the TMX-U device, including measurements of the thermal barrier potential profile using a diagnostic neutral beam and charged particle energy-spectroscopy. We then describe the heavy ion beam probe and other new plasma potential diagnostics that are under development for TMX-U and MFTF-B and examine problem areas where additional diagnostic development is desirable.
Date: September 28, 1984
Creator: Grubb, D.P.
Object Type: Article
System: The UNT Digital Library
Argon Dewar Required Relief Flow Capacity (open access)

Argon Dewar Required Relief Flow Capacity

This report calculates the required fire relief valve flow capacity, the required vaporizer failure relief valve flow capacity, and the required loss of vacuum relief valve flow capacity of the liquid argon storage tank in use at the D-Zero site.
Date: September 28, 1987
Creator: Fitzpatrick, J. B.
Object Type: Report
System: The UNT Digital Library
LANL compact laser pumping simulation. Final task report (open access)

LANL compact laser pumping simulation. Final task report

Rockwell has been tasked with the objective of both qualitatively and quantitatively defining the performance of LANL Compact Laser coupling systems. The performance criteria of the system will be based upon the magnitude and uniformity of the energy distribution in the laser pumping rod. Once this is understood, it will then be possible to improve the device performance via changes in the system`s component parameters. For this study, the authors have chosen to use the Los Alamos Radiometry Code (LARC), which was previously developed by Rockwell. LARC, as an analysis tool, is well suited for this problem because the code contains the needed photometric calculation capability and easily handles the three-dimensionality of the problem. Also, LARC`s internal graphics can provide very informative visual displays of the optical system.
Date: September 28, 1987
Creator: Feldman, B. S. & White, J.
Object Type: Report
System: The UNT Digital Library
Equation of state of partially-ionized dense plasmas (open access)

Equation of state of partially-ionized dense plasmas

This paper describes methods for calculating the equation of state of partially-ionized dense plasmas. The term dense plasma is used rather than strongly coupled plasma, since it is possible that at plasma conditions such that only a few levels can be observed spectroscopically the plasma coupling parameters are not large. Due mainly to their importance in theoretical astrophysics, the properties of partially ionized plasmas have been of interest for a long while. More recently, this interest has intensified due to the development of methods for producing partially ionized plasmas in the laboratory. This has opened up large programs of experimental investigation and of practical application. In this paper we consider detailed statistical mechanical methods that explicitly treat the distribution over ionic species and their energy level structure. These detailed approaches are generally characterized as being in the chemical picture'' when a free energy expression is minimized or in the physical picture'' when the starting point is the grand canonical ensemble. 52 refs., 2 tabs.
Date: September 28, 1989
Creator: Rogers, F. J.
Object Type: Article
System: The UNT Digital Library
Electron beam propagation in the ion focused regime (IFR) with the experimental test accelerator (ETA) (open access)

Electron beam propagation in the ion focused regime (IFR) with the experimental test accelerator (ETA)

The IFR is a well-known stable, low pressure (0.10 to 0.120 torr in air) propagation window. Secondary electrons created by collisions of beam electrons with gas atoms are rapidly expelled by the strong radial electric field of the beam charge. The ions that remain inside the beam partially neutralize the electric field, allowing magnetic pinch forces to focus the beam. Experiments with the ETA beam have re-verified this stable window and are reported. Image forces from a close wall IFR propagation tank are also experimentally shown to center the beam and damp transverse oscillations. Results of experiments using 5 and 15 cm dia beam tubes are reported. For p tau > 2 torr-nsec (gas pressure x time into pulse the beam charge becomes completely neutralized by the ions, allowing a build up of plasma and resultant beam-plasma instabilities. The onset of these instabilities has been measured using rf pickup loops (0 to 2 GHz) and microwave detectors (6 to 40 GHz), and are also reported.
Date: September 28, 1983
Creator: Struve, K. W.; Lauer, E. J. & Chambers, F. W.
Object Type: Article
System: The UNT Digital Library