A study of tau decays of the W boson at CDF (Collider Detector at Fermilab) (open access)

A study of tau decays of the W boson at CDF (Collider Detector at Fermilab)

A report is given of a search for tau decays of the W boson in p{bar p} collisions at {radical}s = 1.8 TeV using the Collider Detector at Fermilab (CDF). A description of a hardware trigger specifically designed to enhance the number of events with tau decays is presented along with the results of a preliminary analysis of data taken during the 1988--89 run of CDF. 10 refs., 4 figs.
Date: January 3, 1990
Creator: Gladney, L. D.
System: The UNT Digital Library
Fission decay in intermediate heavy ion reactions (open access)

Fission decay in intermediate heavy ion reactions

Results are presented on cross sections, parallel and perpendicular momentum transfers, charge loss and velocity systematics for fission following reactions of Fe and Nb projectiles at 50--100 MeV/A on targets of Ta, Au, and Th. The results at 100 MeV/A are compared to a detailed multistage deexcitation model. The initial collision is modeled with an intranuclear cascade. The resultant excited target residues then undergo a fast preequilibrium decay stage followed by a statistical decay involving nucleon evaporation and fission. Results from this modeling are in reasonable agreement with experimental data. 14 refs., 11 figs.
Date: October 3, 1990
Creator: Britt, Harold C.
System: The UNT Digital Library
A Fast Online Event Display for a High Intensity Fixed-Target Spectrometer (open access)

A Fast Online Event Display for a High Intensity Fixed-Target Spectrometer

A workstation-based event display program for the Fermilab Tagged Photon Spectrometer (TPS) is described. Fast displays are required to monitor detector elements, observe hit patterns and energy deposition, and to check track reconstruction. Design considerations, novel features, and performance are designed. 5 refs., 4 figs., 1 tab.
Date: May 3, 1990
Creator: Napier, Austin
System: The UNT Digital Library
BEAR electrostatic analyzer: Flight results (open access)

BEAR electrostatic analyzer: Flight results

The Electrostatic Analyzer (ESA) measured the intensity of charged particles returning to the BEAR payload during flight on 13 July 1989. These particles form part or all of the current that returns to the payload to neutralize the charge ejected with the beam. By measuring the return flux with high time resolution, we can study the physics of charging processes. When the neutralizer was off, the payload emitted 10 mA negative and charged to several hundred volts with a maximum of{approximately}800V. With the neutralizer on (normal configuration) the payload emitted {approximately} 1mA negative and received electrons with energies up to a few hundred volts in some attitudes. This suggests charging to a few hundred volts. The charging rate of the payload is consistent with the rocket body capacitance with respect to a vacuum. 1 ref., 14 figs.
Date: January 3, 1990
Creator: Anderson, Hugh R.; Potter, Douglas W.; Morse, David L.; Olson, Joseph R.; Johnson, J. Lorraine & Pongratz, Morris
System: The UNT Digital Library
Experimental evaluation of vertically versus horizontally split yokes for SSC (Superconducting Super Collider) dipole magnets (open access)

Experimental evaluation of vertically versus horizontally split yokes for SSC (Superconducting Super Collider) dipole magnets

The yoke in SSC dipole magnets provides mechanical support to the collared coil as well as serving as a magnetic element. The yoke and skin are used to increase the coil prestress and reduce collar deflections under excitation. Yokes split on the vertical or horizontal mid-plane offer different advantages in meeting these objectives. To evaluate the relative merits of the two configuration a 1.8 m model dipole was assembled and tested first with horizontally split and then with vertically split yoke laminations. The magnet was extensively instrumented to measure azimuthal and axial stresses in the coil and the cold mass skin resulting from cooldown and excitation. Mechanical behavior of this magnet with each configuration is compared with that of other long and short models and with calculations. 13 refs., 5 figs.
Date: May 3, 1990
Creator: Strait, J.; Coulter, K.; Jaffery, T.; Kerby, J.; Koska, W. & Lamm, M.J.
System: The UNT Digital Library
Fermilab Library projects (open access)

Fermilab Library projects

Preprint database management as done at various centers -- the subject of this workshop -- is hard to separate from the overall activities of the particular center. We therefore present the wider context at the Fermilab Library into which preprint database management fits. The day-to-day activities of the Library aside, the dominant activity at present is that of the ongoing Fermilab Library Automation. A less dominant but relatively time-consuming activity is that of doing more online searches in commercial databases on behalf of laboratory staff and visitors. A related activity is that of exploring the benefits of end-user searching of similar sources as opposed to library staff searching of the same. The Library Automation Project, which began about two years ago, is about to go fully online.'' The rationale behind this project is described in the documents developed during the December 1988--February 1989 planning phase.
Date: May 3, 1990
Creator: Garrett, P. & Ritchie, D.
System: The UNT Digital Library
Simulations of NOVA direct-drive Rayleigh-Taylor experiments (open access)

Simulations of NOVA direct-drive Rayleigh-Taylor experiments

Directly driven Rayleigh-Taylor instability growth experiments being performed on NOVA have been simulated using the computer code, LASNEX. These experiments employ beams smoothed with random phase plates (RPP), and will later include smoothing by spectral dispersion (SSD). Samples are CH foils with or without imposed sinusoidal surface perturbations. Perturbation growth is diagnosed by means of x-ray backlighting. Calculated growth rates are fairly flat across the wavelength range of 20--80 {mu}m which can be accessed experimentally, and are moderately suppressed below classical growth rates. Perturbations of large enough initial amplitude that the contrast in the x-ray image is measurable from the start of the experiment quickly grow into the nonlinear regime. Smaller initial amplitudes result in a longer interval of linear growth, but the initial perturbation will not be detectable in the data. Structure which is predicted to develop from speckles in the RPP beam pattern, with and without SSD, is also presented.
Date: November 3, 1990
Creator: Weber, S.V.
System: The UNT Digital Library
A lattice gas model for thermohydrodynamics (open access)

A lattice gas model for thermohydrodynamics

The FHP lattice gas model is extended to include a temperature variable in order to study thermohydrodynamics. The compressible Navier-Stokes equations are derived using a Chapman-Enskog expansion. Heat conduction and convention problems are investigated, including Benard convention. It is shown that the usual FHP rescaling procedure can be avoided by controlling the temperature. 20 refs., 12 figs.
Date: May 3, 1990
Creator: Chen, Shiyi; Chen, Hudong; Doolen, G. D.; Gutman, S. & Lee, M.
System: The UNT Digital Library