This system will be undergoing maintenance January 21st between 9:00AM and 12:00PM CST.

Search Results

Advanced search parameters have been applied.
open access

Magnetic field, closed orbit, and energy measurement in the Bevatron

Description: This report provides the information necessary for a better evaluation of particle energy in the Bevatron. Previously, the nominal magnetic field value and radius were used to calculate the value for the kinetic energy of the particle. This value was good to a few percent. Today, more and more experimenters would like to know the energy to a more precise value. To this end, corrections to the measured magnetic field values and the radial closed orbit are provided.
Date: November 1, 1981
Creator: Crebbin, K. C.
Partner: UNT Libraries Government Documents Department
open access

Acceleration of beam ions during major radius compression in TFTR

Description: Tangentially co-injected deuterium beam ions were accelerated from 82 keV up to 150 keV during a major radius compression experiment in TFTR. The ion energy spectra and the variation in fusion yield were in good agreement with Fokker-Planck code simulations. In addition, the plasma rotation velocity was observed to rise during compression.
Date: September 1, 1985
Creator: Wong, K. L.; Bitter, M.; Hammett, G. W.; Heidbrink, W.; Hendel, H.; Kaita, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Hydrogen bonding in asphaltenes and coal. Progress report, March 1, 1977--August 31, 1977

Description: A calorimetric method is presented for the simultaneous evaluation of equilibrium constant, K, and molar enthalpy, ..delta..H/sup 0/, for 1 : 1 adduct formation of quinoline (Qu) with asphaltene (A), together with its acid/neutral (AA) fraction and its base (BA) fraction, isolated from a centrifuged liquid product (CLP) sample prepared from Kentucky hvAb coal at 27.6 MPa hydrogen pressure and 723K, with reactor charged with glass pellets. The same procedure was used to determine K and ..delta..… more
Date: August 1, 1977
Creator: Li, N. C. & Tewari, K. C.
Partner: UNT Libraries Government Documents Department
open access

Hot-ion distribution function in ORMAK, the Oak Ridge Tokamak

Description: A distortion of the Maxwellian ion-energy distribution function in tokamak-produced plasmas may be revealed in the spectral-line radiation. We report experimental evidence that (1) a change in the value of Z/sub eff/, (2) delayed gas injection, (3) neutral beam injection, and (4) liner cleaning procedures can alter the profile of the Balmer-..cap alpha.. (6563 A) line of hydrogen. The distortion is analyzed in terms of an effective toroidal-drift velocity, ion-temperature relation.
Date: March 1, 1978
Creator: Neidigh, R.V. & Sigmar, D.J.
Partner: UNT Libraries Government Documents Department
open access

Emission in the 50-80 A region from highly ionized silver in PLT tokamak plasmas

Description: The spectrum of silver emitted by Princeton Large Torus (PLT) tokamak plasmas has been recorded in the 25 to 150 A region by a multichannel time-resolving grazing-incidence spectrometer. Silver atoms have been introduced in the tokamak plasma using the laser blow-off technique. For the first time, lines emitted within the 3p-3d transitions of Ag XXIX, Ag XXX, and Ag XXXI ions, between 50 and 80 A, have been identified.
Date: September 1, 1985
Creator: Schwob, J.L.; Wouters, A.; Suckewer, S.; Cohen, S.A. & Finkenthal, M.
Partner: UNT Libraries Government Documents Department
open access

Radiation dosimetry through spectral definition

Description: We have developed a fieldable instrumentation system for determining from measured flux spectra, both the neutron and gamma ray dose rate distributions associated with radioactive sources. This system includes the sensors, the computer-based data acquisition and analysis hardware, and the requisite software for unfolding the sensor response functions to obtain the flux spectra, and for folding the resultant flux spectra with appropriate flux spectrum-to-dose conversion factors. We use bismuth g… more
Date: January 1, 1985
Creator: Dowdy, E. J.; Moss, C. E.; Robba, A. A.; Evans, A. E.; Lucas, M. C.; Shunk, E. R. et al.
Partner: UNT Libraries Government Documents Department
open access

Sensitivity of primary knock-on atom spectra and displacement per atom cross sections to different secondary neutron energy and angular distributions and ''in-group'' weighting schemes

Description: The sensitivity of primary knock-on atom (PKA) spectra and displacement per atom (DPA) cross sections to different secondary neutron energy and angular distributions and ''in-group'' weighting schemes is investigated. It is shown that the sensitivity of the PKA spectra and DPA cross sections for the (n,n' unresolved) and (n,2n) reactions in Fe to different angular distributions and the same secondary neutron spectrum is reasonably large (approximately 15%), whereas the … more
Date: January 1, 1978
Creator: Gabriel, T. A. & Bishop, B. L.
Partner: UNT Libraries Government Documents Department
open access

Background radiation from fission pulses

Description: Extensive source terms for beta, gamma, and neutrons following fission pulses are presented in various tabular and graphical forms. Neutron results from a wide range of fissioning nuclides (42) are examined and detailed information is provided for four fuels: /sup 235/U, /sup 238/U, /sup 232/Th, and /sup 239/Pu; these bracket the range of the delayed spectra. Results at several cooling (decay) times are presented. For ..beta../sup -/ and ..gamma.. spectra, only /sup 235/U and /sup 239/Pu result… more
Date: May 1, 1988
Creator: England, T. R.; Arthur, E. D.; Brady, M. C. & LaBauve, R. J.
Partner: UNT Libraries Government Documents Department
open access

Vapor phase spectroscopy of complex lanthanide halide--aluminum halide molecular species

Description: The absorption spectrum of ErCl/sub 3/ (AlCl/sub 3/)/sub x/ vapor complex was measured and analyzed using the Judd-Ofelt theory. Structural correlations in other AlCl/sub 3/ vapor complexes and radiation emission are discussed. Fluorescence of TbCl/sub 3/ (AlCl/sub 3/)/sub x/ vapor complex and in the NdCl/sub 3/ (AlCl/sub 3/)/sub x/ system were studied. (DLC)
Date: January 1, 1977
Creator: Carnall, W T; Hessler, J P; Williams, C W & Hoekstra, H R
Partner: UNT Libraries Government Documents Department
open access

High resolution x-ray crystal spectrographs

Description: Observation of x-ray line emissions are valuable for determining the thermodynamic state of the emitting plasma. For laser produced plasmas, diffraction crystals can be used to isolate x-ray monochromes to obtain high resolution spectral measurements. We will describe a versatile multi-crystal high resolution spectrograph used for photon energies from 0.5 to 6 keV. We will discuss a calculational package that tunes the response and sensitivity of the instrument and estimates the effect of sourc… more
Date: October 21, 1977
Creator: Koppel, L. N. & Eckels, J. D.
Partner: UNT Libraries Government Documents Department
open access

HIFI: a computer code for projectile fragmentation accompanied by incomplete fusion

Description: A brief summary of a model proposed to describe projectile fragmentation accompanied by incomplete fusion and the instructions for the use of the computer code HIFI are given. The code HIFI calculates single inclusive spectra, coincident spectra and excitation functions resulting from particle-induced reactions. It is a multipurpose program which can calculate any type of coincident spectra as long as the reaction is assumed to take place in two steps.
Date: July 1, 1980
Creator: Wu, J.R.
Partner: UNT Libraries Government Documents Department
open access

Spectra of negative particles and photons in collisions of p/minus/W and /sup 16/O/minus/W at 200 GeVu

Description: /rho//perpendicular/ spectra of negative particles were measured for p/minus/W and /sup 16/O/minus/W collisions at 200 GeVupsilon in the rapidity range 0.9< y <1.9. Within the systematic errors of 20% the spectra are indentical in the range 0.05 </rho//perpendicular/<2.0 GeVc. The p/minus/W and /sup 16/O /minus/W spectra exhibit an exponential shape for /rho//perpendicular/>250 MeVc. This is consistent with previous p/minus/A data, but there is a significant excess above this exponential at low… more
Date: January 1, 1987
Creator: Bartels, H.W.
Partner: UNT Libraries Government Documents Department
open access

Probing nuclear matter with dileptons

Description: Dileptons are shown to be of interest in helping probe extreme conditions of temperature and density in nuclear matter. The current state of experimental knowledge about dileptons is briefly described, and their use in upcoming experiments with light ions at CERN SPS are reviewed, including possible signatures of quark matter formation. Use of dileptons in an upcoming experiment with a new spectrometer at Berkeley is also discussed. This experiment will probe the nuclear matter equation of stat… more
Date: June 1, 1986
Creator: Schroeder, L. S.
Partner: UNT Libraries Government Documents Department
open access

Time-resolved x-ray line diagnostics of laser-produced plasmas

Description: We have examined the underdense plasma conditions of laser irradiated disks using K x-rays from highly ionized ions. A 900 ps laser pulse of 0.532 ..mu..m light is used to irradiate various Z disks which have been doped with low concentrations of tracer materials. The tracers whose Z's range from 13 to 22 are chosen so that their K x-ray spectrum is sensitive to typical underdense plasma temperatures and densities. Spectra are measured using a time-resolved crystal spectrograph recording the ti… more
Date: January 1, 1982
Creator: Kauffman, R.L.; Matthews, D.L.; Kilkenny, J.D. & Lee, R.W.
Partner: UNT Libraries Government Documents Department
open access

Configuring the SLC linac for injection into PEP

Description: From time to time the normal SLC physics program is to be interrupted so that beam can be delivered to PEP. In order that the switch to PEP injection (and the switch back again) can be accomplished quickly and easily, the gun, the damping rings, the linac phase ramp, the energy profile of the linac klystrons for the scavenger bunch, and the entire positron production system are to be kept the same as in the SLC configuration. What mainly remains to be changed is the linac klystron profile for t… more
Date: December 15, 1989
Creator: Bane, K.L.F.
Partner: UNT Libraries Government Documents Department
open access

Design of neutron streak camera for fusion diagnostics

Description: The D-T burn time for advanced laser-fusion targets is calculated to be very short, < 50 ps. We describe the design of a neutron streak camera of 16 ps resolving time that can be used to study the temporal history of fusion burn. The cathode of the neutron streak camera is sensitive to neutrons and is curved such that the difference in the neutron path lengths from a point source to various parts of the cathode is compensated by electron transit times within the streak tube. Thus the cathode ca… more
Date: June 1, 1982
Creator: Wang, C. L.; Kalibjian, R. & Singh, M. S.
Partner: UNT Libraries Government Documents Department
open access

Strange particle production in neutrino-neon charged current interactions

Description: Neutral strange particle production in charged-current muon-neutrino interactions have been studied in the Fermilab 15-foot neon bubble chamber. Associated production is expected to be the major source of strange particles in charged-current neutrino interactions. sigma-neutral and xi-minus production by neutrinos was observed. The dependence on various leptonic and hadronic variables is investigated. A fit to single and associated production of s, s/anti-s, and c quarks is described based on t… more
Date: January 1, 1986
Creator: Plano, R.; Baker, N. J.; Connolly, P. L.; Kahn, S. A.; Murtagh, M. J.; Palmer, R. B. et al.
Partner: UNT Libraries Government Documents Department
open access

The Fresh-Bunch' technique in FELs

Description: The 'Fresh Bunch' technique is being proposed as a method of increasing the gain and power of FEL amplifiers in which the length of the optical radiation pulse is shorter than the length of the electron bunch. In multi-stage FEL, electron beam energy spread is increased by the FEL interaction in the early stages. In the 'Fresh Bunch' technique, the low energy spread of the electron beam is recovered by shifting the radiation pulse to an undisturbed part of the electron bunch, thus improving the… more
Date: January 1, 1991
Creator: Ben-Zvi, Ilan; Yang, K. M. & Yu, L. H.
Partner: UNT Libraries Government Documents Department
open access

Ion transport in stellarators

Description: Stellarator ion transport in the low-collisionality regime with a radial electric field is calculated by a systematic expansion of the drift-Boltzmann equation. The shape of the helical well is taken into account in this calculation. It is found that the barely trapped ions with three to four times the thermal energy give the dominant contribution to the diffusion. Expressions for the ion particle and energy fluxes are derived.
Date: September 1, 1985
Creator: Ho, D.D.M. & Kulsrud, R.M.
Partner: UNT Libraries Government Documents Department
open access

Gamma rays from Cygnus X-1: Modeling and nonthermal pair production

Description: The gamma-ray bump observed between 0.5 and 2 MeV in the spectrum of Cygnus X-1 can be interpreted as the thermal emissions from a hot (kT)approximately)400 keV) pair-dominated cloud. We argue that the X-rays and gamma rays are produced in separate emission regions, and calculate the photon-photon pair production rate from X-ray and gamma-ray interactions in the vicinity of Cyg X-1 by employing a simplified geometry for the two emitting regions.
Date: February 1, 1988
Creator: Dermer, C. D. & Liang, E. P.
Partner: UNT Libraries Government Documents Department
open access

A search for the production of the final states. tau. sup +. tau. sup minus e sup + e sup minus ,. tau. sup +. tau. sup minus. mu. sup +. mu. sup minus , and. tau. sup +. tau. sup minus. pi. sup +. pi. sup minus in e sup + e sup minus collisions at radical s = 29 GeV

Description: We have searched for the reaction e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}}{bar f}f, where f is either an electron, muon, or charged pion, at {radical}s = 29 GeV using the Mark 2 detector at the PEP storage ring. One candidate event is found while 2.3 events are expected from known processes. We would expect to see 11 events if the cross-section for e{sup +}e{sup {minus}} {yields} {tau}{sup +}{tau}{sup {minus}}{bar f}f at {radical}s = 29 GeV were enhanced by the factor of 4… more
Date: July 1, 1991
Partner: UNT Libraries Government Documents Department
open access

Profile correction to electron temperature and enhancement factor in soft x-ray pulse-height-analysis measurements in tokamaks

Description: Because soft x-ray pulse-height-analysis (PHA) spectra contain chordal information, the electron temperature and the radiation intensity (enhancement factor) measurements do not represent the local values. Assuming that the profile Ansatz for the electron temperature and density is of the form n/sub eo/(1-(ra)/sup 2/)/sup ..cap alpha../ and kT/sub eo/(1--(ra)/sup 2/)/sup ..beta../, we obtain the correction factors for the electron temperature and the enhancement factor as a function of the prof… more
Date: April 1, 1988
Creator: Sesnic, S.; Diesso, M.; Hill, K.; Holland, A. & Pohl, F.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen