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Transverse energy distribution, charged particle multiplicities and spectra in /sup 16/O--nucleus collisions (open access)

Transverse energy distribution, charged particle multiplicities and spectra in /sup 16/O--nucleus collisions

The HELIOS (High Energy Lepton and Ion Spectrometer) experiment, installed at the CERN Super Proton Synchrotron, proposes to examine in detail the physical properties of a state of high energy created in nuclei by ultra-relativistic nucleus-nucleus collisions. It is generally believed that, at high densities or temperatures, a phase transition to a plasma of quark and gluons will occur. The dynamic of the expansion of such a plasma and its subsequent condensation into a hadron gas should markedly affect the composition and momentum distribution of the emerging particles and photons. The HELIOS experimental setup therefore combines 4..pi.. calorimetric coverage with measurements of inclusive particle spectra, two particle correlations, low and high mass lepton pairs and photons. The emphasis is placed on transverse energy flow (E/sub /tau//) measurements with good energy resolution, and the ability to trigger the acquisition of data in a variety of E/sub /tau// ranges, thereby selecting the impact parameter or the violence of the collisions. This short note presents HELIOS results, for the most part still preliminary, on /sup 16/O--nucleus collisions at the incident energies of 60 and 200 GeV per nucleon. The E /sub /tau// distributions from Al, Ag and W targets are discussed and compared …
Date: November 26, 1987
Creator: Sunier, J. W.
System: The UNT Digital Library
Characterization of optical surface degradation: Angular resolved scatterometer (open access)

Characterization of optical surface degradation: Angular resolved scatterometer

The Angular Resolved Scatterometer (ARS) is a sensitive diagnostic instrument for quantitatively specifying the degree of degradation for optical surfaces. ARS test results are reported for coatings undergoing aboveground (AGT) prompt x-ray irradiation. With the ARS, the light scattered from an optical surface is measured as a function of scattering angle, wavelength, and polarization. From these data the power spectral density (PSD) is calculated and contains the bandwidth-limited spatial information about the surface. Subtle changes in surface properties (e.g., radiation-induced absorption, polarization changes, or localized incipient melting) that would not be detected by surface roughness or reflectance measurements appear as a significant PSD change. The ARS data are an integration over all spatial frequencies and thus accurately and uniquely characterize each surface.
Date: February 26, 1987
Creator: Edwards, D.F.; Gillespie, C.H. & Wirtenson, G.R.
System: The UNT Digital Library
Transport vehicle for manned Mars missions powered by inertial confinement fusion (open access)

Transport vehicle for manned Mars missions powered by inertial confinement fusion

Inertial confinement fusion (ICF) is an ideal engine power source for manned spacecraft to Mars because of its inherently high power-to-mass ratios and high specific impulses. We have produced a concept for a vehicle powered by ICF and utilizing a magnetic thrust chamber to avoid plasma thermalization with wall structures and the resultant degradation of specific impulse that are unavoidable with the use of mechanical thrust chambers. This vehicle is capable of 100-day manned Mars missions with a 100-metric-ton payload and a total vehicle launch mass near 6000 metric tons, based on advanced technology assumed to be available by A.D. 2020. Such short-duration missions minimize radiation exposures and physiological deterioration of astronauts.
Date: June 26, 1987
Creator: Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K. & Chang-Diaz, F.
System: The UNT Digital Library
Probing electroweak symmetry breaking at multi-TeV colliders (open access)

Probing electroweak symmetry breaking at multi-TeV colliders

Low energy theorems are derived for scattering of longitudinally polarized W and Z's, providing the basis for an estimate of the observable signal if electroweak symmetry breaking is due to new physics at the TeV scale. A pp collider with L, {radical}s {equals} 40 TeV, 10{sup 33}cm. {sup {minus}2}s{sup {minus}1} is just sufficient to observe the signal while pp colliders with 40, 10{sup 32} or 20, 10{sup 33} are not. A collider that is sensitive to the TeV-scale signal provides valuable information about symmetry breaking whether the masses of the associated new particles are below, within, or above the 1-2 TeV region. 6 refs., 6 figs., 2 tabs.
Date: March 26, 1987
Creator: Chanowitz, Michael S.
System: The UNT Digital Library
Oklahoma's Residential High School: Cultivating Scholars (open access)

Oklahoma's Residential High School: Cultivating Scholars

First page of an article on the creation of a special residential high school in Oklahoma, wherein Texas is mentioned as a state that has already done so.
Date: October 26, 1987
Creator: unknown
System: The UNT Digital Library