Applied chromodynamics (open access)

Applied chromodynamics

A number of novel features of QCD are reviewed, including the consequences of formation zone and color transparency phenomena in hadronic collisions, the use of automatic scale setting for perturbative predictions, null-zone phenomena as a fundamental test of gauge theory, and the relationship of intrinsic heavy colored particle Fock state components to new particle production. We conclude with a review of the applications of QCD to nuclear multiquark systems. 74 references.
Date: November 1, 1983
Creator: Brodsky, S. J.
System: The UNT Digital Library
Transport in compact tori (open access)

Transport in compact tori

The parameter B/sub e//nr/sub p/ (here, B/sub e/ is applied magnetic field strength, nr/sub p/ is the plasma density-radius product) is proposed as a key parameter for spheromak heating studies. If B/sub e//nr/sub p/ is too large, increased magnetic fluctuations limit heating; low B/sub e//nr/sub p/ value results in excessive radiation losses. An optimum range appears to be B/sub e//nr/sub p/ approx. 1 to 5 x 10/sup -20/ Wb.
Date: February 23, 1983
Creator: Miley, G. H.
System: The UNT Digital Library
Transient fission gas release during direct electrical heating experiments (open access)

Transient fission gas release during direct electrical heating experiments

The gas release behavior of irradiated EBR-II fuel was observed to be dependent on several factors: the presence of cladding, the retained gas content, and the energy absorbed. Fuel that retained in excess of 16 to 17 ..mu..moles/g of fission gas underwent spallation as the cladding melted and released 22 to 45% of its retained gas, while fuel with retained gas levels below approx. 15 to 16 ..mu..moles/g released less than approx. 9% of its gas as the cladding melted. During subsequent direct electrical heating ramps, fuel that did not spall released an additional quantity of gas (up to 4 ..mu..moles/g), depending on the energy absorbed.
Date: December 1, 1983
Creator: Fenske, G. R.; Emerson, J. E. & Savoie, F. E.
System: The UNT Digital Library
Grand unified theories (open access)

Grand unified theories

Topics discussed include coupling constants; minimal SU(5) predictions (sin/sup 2/theta/sub W/, m/sub W/ and m/sub Z/, proton decay, and magnetic monopoles); Higgs scalar effects including proton decay and flavor changing and oscillation phenomena; and supersymmetry. 31 references.
Date: September 11, 1983
Creator: Marciano, W. J.
System: The UNT Digital Library
Position-sensitive fission counter for in-core flux profile monitoring (open access)

Position-sensitive fission counter for in-core flux profile monitoring

A prototype model of a position-sensitive fission counter (PSFC) was developed for power-range flux profile monitoring in light-water reactor cores. The flux profile is measured by delay-line position encoding and time interval decoding of individual fission pulses from 11 small fission counters incorporated along a coaxial transmission line. Significant improvements over currently used flux profile monitors are the 33-cm spatial resolution of the 3.5-m-long PSFC and the requirement for only one cable penetration into the reactor pressure vessel.
Date: January 1, 1983
Creator: Kopp, M. K.; Valentine, K. H.; Guerrant, G. C. & Harter, J. A.
System: The UNT Digital Library
Sparking protection for MFTF-B neutral beam power supplies (open access)

Sparking protection for MFTF-B neutral beam power supplies

This paper describes the upgrade of MFTF-B Neutral Beam Power Supplies for sparking protection. High performance ion sources spark repeatedly so ion source power supplies must be insensitive to sparking. The hot deck houses the series tetrode, arc and filament supplies, and controls. Hot deck shielding has been upgraded and a continuous shield around the arc, filament, gradient grid, and control cables now extends from the hot deck, through the core snubber, to the source. The shield carries accelerating current and connects only to the source. Shielded source cables go through an outer duct which now connects to a ground plane under the hot deck. This hybrid transmission line is a low inductance path for sparks discharging the stray capacitance of the hot deck and isolation transformers, reducing coupling to building steel. Parallel dc current return cables inside the duct lower inductance to reduce inductive turn-off transients. MOVs to ground further limit surges in the remote power supply return. Single point grounding is at the source. No control or rectifier components have been damaged nor are there any known malfunctions due to sparking up to 80 kV output.
Date: November 30, 1983
Creator: Cummings, D. B.
System: The UNT Digital Library
New kind of user interface for controlling MFTF diagnostics (open access)

New kind of user interface for controlling MFTF diagnostics

The Mirror Fusion Test Facility (MFTF) at Lawrence Livermore National Laboratory is faced with the problem of controlling a multitude of plasma diagnostics instruments from a central, multiprocessor computer facility. A 16-bit microprocessor-based workstation allows each physicist entree into the central multiprocessor, which consists of nine Perkin-Elmer 32-bit minicomputers. The workstation provides the user interface to the larger system, with display graphics, windowing, and a physics notebook. Controlling a diagnostic is now equivalent to making entries into a traditional physics notebook.
Date: November 29, 1983
Creator: Preckshot, George G.; Saroyan, Ralph A. & Mead, John E.
System: The UNT Digital Library
Improvement in MFTF data base system response times (open access)

Improvement in MFTF data base system response times

The Supervisory Control and Diagnostic System for the Mirror Fusion Test Facility (MFTF) has been designed as an event driven system. To this end we have designed a data base notification facility in which a task can request that it be loaded and started whenever an element in the data base is changed beyond some user defined range. Our initial implementation of the notify facility exhibited marginal response times whenever a data base table with a large number of outstanding notifies was written into. In this paper we discuss the sources of the slow response and describe in detail a new structure for the list of notifies which minimizes search time resulting in significantly faster response.
Date: November 28, 1983
Creator: Lang, Neil C. & Nelson, Bron C.
System: The UNT Digital Library
Particle ratios at high transverse momentum in pp collisions at. sqrt. s = 63 GeV and correlations between high p/sub T/ identified charged particles and associated identified charged particles (open access)

Particle ratios at high transverse momentum in pp collisions at. sqrt. s = 63 GeV and correlations between high p/sub T/ identified charged particles and associated identified charged particles

The production of identified charged particles in pp collisions at ..sqrt..s = 63 GeV with an identified high p/sub T/ trigger particle emitted in the central region is studied. The measurements were performed at the CERN ISR using the Axial Field Spectrometer. Trigger particle ratios, sigma(..pi../sup + -/)/ sigma(all/sup + -/), sigma(K/sup + -/) and sigma(p/sup + -/)/sigma(all/sup + -/) are presented for p/sub T/ from 5 GeV/c to 8 GeV/c. In addition sigma(..pi../sup + -/)/sigma(all/sup + -/) is presented in the p/sub T/ region from 2.5 GeV/c to 4.5 GeV/c. The charge compensation in the hemisphere containing the trigger particle is shown to depend strongly on the identity of the trigger particle and on the identity of the associated particles. 13 references.
Date: January 1, 1983
Creator: Akesson, T.; Albrow, M. G.; Almehed, S.; Batley, R.; Benary, O.; Boggild, H. et al.
System: The UNT Digital Library
Control of activation levels to simplify waste management of fusion reactor ferritic steel components (open access)

Control of activation levels to simplify waste management of fusion reactor ferritic steel components

Activation characteristics of a material for service in the neutron flux of a fusion reactor first wall fall into three areas: waste management, reactor maintenance and repair, and safety. Of these, the waste management area is the most likely to impact the public acceptance of fusion reactors for power generation. The decay of the activity in steels within tens of years could lead to simplified waste disposal or possibly even to materials recycle. Whether or not these can be achieved will be controlled by (1) selection of alloying elements, (2) control of critical impurity elements, and (3) control of cross contamination from other reactor components. Several criteria can be used to judge the acceptability of potential alloying elements in iron, and to define the limits on content of critical impurity elements. One approach is to select and limit alloying additions on the basis of the activity. If material recycle is a goal, N, Al, Ni, Cu, Nb, and Mo must be excluded. If simplified waste storage by shallow land burial is the goal, regulations limit the concentration of only a few isotopes. For first-wall material that will be exposed to 9 MW-y/m/sup 2/ service, allowable initial concentration limits include (in …
Date: January 1, 1983
Creator: Wiffen, F. W. & Santoro, R. T.
System: The UNT Digital Library
Computer model of the MFTF-B neutral beam Accel dc power supply (open access)

Computer model of the MFTF-B neutral beam Accel dc power supply

Using the SCEPTRE circuit modeling code, a computer model was developed for the MFTF Neutral Beam Power Supply System (NBPSS) Accel dc Power Supply (ADCPS). The ADCPS provides 90 kV, 88 A, to the Accel Modulator. Because of the complex behavior of the power supply, use of the computer model is necessary to adequately understand the power supply's behavior over a wide range of load conditions and faults. The model developed includes all the circuit components and parameters, and some of the stray values. The model has been well validated for transients with times on the order of milliseconds, and with one exception, for steady-state operation. When using a circuit modeling code for a system with a wide range of time constants, it can become impossible to obtain good solutions for all time ranges at once. The present model concentrates on the millisecond-range transients because the compensating capacitor bank tends to isolate the power supply from the load for faster transients. Attempts to include stray circuit elements with time constants in the microsecond and shorter range have had little success because of huge increases in computing time that result. The model has been successfully extended to include the accel modulator.
Date: November 30, 1983
Creator: Wilson, J. H.
System: The UNT Digital Library
Local area network for the plasma diagnostics system of MFTF-B (open access)

Local area network for the plasma diagnostics system of MFTF-B

The MFTF-B Plasma Diagnostics System will be implemented in stages, beginning with a start-up set of diagnostics and evolving toward a basic set. The start-up set contains 12 diagnostics which will acquire a total of about 800 Kbytes of data per machine pulse; the basic set contains 23 diagnostics which will acquire a total of about 8 Mbytes of data per pulse. Each diagnostic is controlled by a Foundation System consisting of a DEC LSI-11/23 microcomputer connected to CAMAC via a 5 Mbits/second serial fiber-optic link and connected to a supervisory computer (Perkin-Elmer 3250) via a 9600 baud RS232 link. The Foundation System is a building block used throughout MFTF-B for control and status monitoring. However, its 9600 baud link to the supervisor presents a bottleneck for the large data transfers required by diagnostics. To overcome this bottleneck the diagnostics Foundation Systems will be connected together with an additional LSI-11/23 called the master to form a Local Area Network (LAN) for data acquisition.
Date: January 1, 1983
Creator: Lau, N. H. & Minor, E. G.
System: The UNT Digital Library
Alternative power supply and dump resistor connections for similar, mutally coupled, superconducting coils (open access)

Alternative power supply and dump resistor connections for similar, mutally coupled, superconducting coils

Alternative methods of connecting similar mutually coupled coils to their power supplies and dump resistors are investigated. The circuits are evaluated for both operating and fault conditions. The factors considered are the voltage to ground during a dump, short circuits, open circuits, quenches, and failure of the protection system to detect a quench. Of particular interest are the currents induced in coils that remain superconducting when one or more coils quench. The alternative connections include combined power supplies, individual dump resistors, combined resistors and series and parallel dump resistors. A new circuit that contains coupling resistors is proposed. The coupling resistors do not affect normal fast dumps but reduce the peak induced currents while also reducing the energy rating of the dump resistors. Another novel circuit, the series circuit with diodes, is discussed. The MFTF-B central-cell solenoids are used as an example.
Date: November 30, 1983
Creator: Owen, E. W.; Shimer, D. W. & Wang, S. T.
System: The UNT Digital Library
SP-100, a project manager`s view. Technical information report (open access)

SP-100, a project manager`s view. Technical information report

Born to meet the special needs of America`s space effort, the SP-100 Program testifies to the cooperation among government agencies. The Department of Energy (DOE), the National Aeronautics and Space Administration (NASA), and the Defense Advanced Research Projects Agency (DARPA) are working together to produce a 100-kW power system for use in outer space. At this point in the effort, it is appropriate to review: The approach to meet program goals; the status of activities of the Project Office, managed by the Jet Propulsion Laboratory (JPL); and, because this is a meeting on materials, answers beings developed by the Project Office to vital questions on refractory alloy technology.
Date: December 1, 1983
Creator: Truscello, V. C.
System: The UNT Digital Library
Proceedings of the Monterey Containment Symposium, Monterey, California, August 26-28, 1981. Volume 1 (open access)

Proceedings of the Monterey Containment Symposium, Monterey, California, August 26-28, 1981. Volume 1

Since the Atmospheric Test Ban Treaty was signed in 1963, the United States has conducted all nuclear weapons tests underground. To meet US treaty responsibilities and to ensure public safety, the containment community must prevent any release of radioactive gases to the atmosphere. In the past two decades we have gained considerable insight into the scientific and engineering requirements for complete containment, but the papers and discussions at the Monterey Symposium indicate that a great deal remains to be done. Among papers included here, those dealing with mature topics will serve as reviews and introductions for new workers in the field. Others, representing first looks at new areas, contain more speculative material. Active research topics include propagation of stress waves in rocks, formation and decay of residual hoop stresses around a cavity, hydrofracture out of a cavity, formation of chimneys, and geologic and geophysical investigations of the Nevada Test Site. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
Date: February 1, 1983
Creator: Hudson, B. C.; Lawrence Livermore National Lab., CA (United States)]; Jones, E. M.; Los Alamos National Lab., NM (United States)]; Keller, C. E.; Field Command (DNA), Kirtland Air Force Base, NM (United States)] et al.
System: The UNT Digital Library
Design of periodic beam-transport systems (open access)

Design of periodic beam-transport systems

Periodic beam-transport systems have several advantages including insensitivity to errors, minimum magnet apertures, and use of standardized components. A simple procedure is given for the design of modules, with and without bending magnets, that have the same matched beam properties. These modules can be combined in certain ways to produce systems that are achromatic and require a minimum number of matching elements.
Date: January 1, 1983
Creator: Farrell, J.A.
System: The UNT Digital Library
Linear radial pulsation theory. Lecture 5 (open access)

Linear radial pulsation theory. Lecture 5

We describe a method for getting an equilibrium stellar envelope model using as input the total mass, the envelope mass, the surface effective temperature, the total surface luminosity, and the composition of the envelope. Then wih the structure of the envelope model known, we present a method for obtaining the raidal pulsation periods and growth rates for low order modes. The large amplitude pulsations observed for the yellow and red giants and supergiants are always these radial models, but for the stars nearer the main sequence, as for all of our stars and for the white dwarfs, there frequently are nonradial modes occuring also. Application of linear theory radial pulsation theory is made to the giant star sigma Scuti variables, while the linear nonradial theory will be used for the B stars in later lectures.
Date: January 1, 1983
Creator: Cox, A. N.
System: The UNT Digital Library
Linear and nonlinear analysis of high-power rf amplifiers (open access)

Linear and nonlinear analysis of high-power rf amplifiers

After a survey of the state variable analysis method the final amplifier for the CBA is analyzed taking into account the real beam waveshape. An empirical method for checking the stability of a non-linear system is also considered.
Date: January 1, 1983
Creator: Puglisi, M.
System: The UNT Digital Library
Line-coincidence schemes for producing laser action at soft-x-ray wavelengths (open access)

Line-coincidence schemes for producing laser action at soft-x-ray wavelengths

Line-coincidence schemes for producing laser action in the wavelength regime 100-30A are reviewed. Schemes involving pumping of 2..-->..4 transitions in neon-like ions are singled out as particularly attractive.
Date: January 12, 1983
Creator: Chapline, George F.
System: The UNT Digital Library
Errors in radio-frequency quadrupole structures (open access)

Errors in radio-frequency quadrupole structures

Performance degradation caused by certain radio-frequency quadrupole (RFQ) machine errors was studied using an efficient 3-D particle-tracing simulation code for a high-brightness example. Matched beams, for which no emittance growth occurs, exist for periodic structures and were used as input beams for particle tracing in the presence of errors. We considered both slowly varying and fast (random) errors that destroy periodicity. Random dipole errors cause emittance growth because of the mismatches they introduce and also result in a motion of the beam centroid that causes a reduction in acceptance. Because of the way RFQs are manufactured, the random error amplitudes can be kept below harmful levels. More important are the slow errors, which are harmful because they reduce acceptance even though they maintain a match (up to the point of particle loss). Slow dipole errors steer the beam toward the wall, and voltage deficiencies cause instabilities in the longitudinal direction resulting in particles not being accelerated to full energy.
Date: January 1, 1983
Creator: Lysenko, W.P.
System: The UNT Digital Library
Electromagnetic direct implicit PIC simulation (open access)

Electromagnetic direct implicit PIC simulation

Interesting modelling of intense electron flow has been done with implicit particle-in-cell simulation codes. In this report, the direct implicit PIC simulation approach is applied to simulations that include full electromagnetic fields. The resulting algorithm offers advantages relative to moment implicit electromagnetic algorithms and may help in our quest for robust and simpler implicit codes.
Date: March 29, 1983
Creator: Langdon, A. Bruce
System: The UNT Digital Library
Closed-orbit correction of the NSLS VUV ring (open access)

Closed-orbit correction of the NSLS VUV ring

We describe the results obtained from the orbit correction system in the NSLS VUV storage ring which consists of 24 PUE stations and 16 horizontal and vertical correction dipoles. The data were obtained by the PUEREAL module of the RING control program which provides automatic switching of the signal from individual electrodes of the PUE stations and provides a readout at harmonic of the rf frequency. The closed orbit is then calculated and corrected by measured displacements of the PUE's from the adjacent quadrupoles. The ORBIT module of the RING program was used to minimize the RMS orbit deviations choosing the most effective correctors and calculating their strengths. For the horizontal case, the correction was accomplished using 3 correctors in two iterations starting with RMS values X = 2.9 mm to X = 0.9 mm. Vertically three iterations and 6 correctors were required to correct the RMS value from Z = 6.8 nm to Z = 0.8 mm.
Date: January 1, 1983
Creator: Bozoki, E.; Bittner, J.; Blumberg, L.; Dickinson, T. & Galayda, J.
System: The UNT Digital Library
Measurement and simulation of the drift pulses and resolution in the micro-jet chamber (open access)

Measurement and simulation of the drift pulses and resolution in the micro-jet chamber

We have tested a prototype of a micro-jet chamber, using both a nitrogen laser and a 10GeV electron beam. The achieved resolution in the particle beam was sigma = 18..mu..m for a lmm impact parameter and 22..mu..m when averaging over the entire beam profile. The experimental results were compared to a Monte Carlo program which simulates the pulse shapes and resolution in drift chambers of any geometry. The main emphasis in our simulation analysis was to study various strategies for drift chambers in order to achieve the best possible timing resolution.
Date: January 1, 1983
Creator: Va'vra, J.
System: The UNT Digital Library
Momentum Integral Network Method for Thermal-Hydraulic Transient Analysis. [LMFBR] (open access)

Momentum Integral Network Method for Thermal-Hydraulic Transient Analysis. [LMFBR]

A new momentum integral network method has been developed, and tested in the MINET computer code. The method was developed in order to facilitate the transient analysis of complex fluid flow and heat transfer networks, such as those found in the balance of plant of power generating facilities. The method employed in the MINET code is a major extension of a momentum integral method reported by Meyer. Meyer integrated the momentum equation over several linked nodes, called a segment, and used a segment average pressure, evaluated from the pressures at both ends. Nodal mass and energy conservation determined nodal flows and enthalpies, accounting for fluid compression and thermal expansion.
Date: 1983
Creator: Van Tuyle, Gregory J.
System: The UNT Digital Library