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open access

The multipulse Thomson scattering diagnostic on the DIII-D tokamak

Description: This paper describes the design and operation of a 40-spatial channel Thomson scattering system that uses multiple 20 Hz Nd:YAG lasers to measure the electron temperature and density profiles periodically throughout an entire plasma discharge. Interference filter polychromators disperse the scattered light which is detected by silicon avalanche photodiodes. The measurable temperature range from 10 eV to 20 keV and the minimum detectable density is about 2 {times} 10{sup 18} m{sup {minus}3}. Las… more
Date: September 1, 1991
Creator: Carlstrom, T. N.; Campbell, G. L.; DeBoo, J. C.; Evanko, R. G.; Evans, J.; Greenfield, C. M. et al.
Partner: UNT Libraries Government Documents Department
open access

Prospects of physics at CDF with the SVX

Description: During next physics run CDF will strongly enhance its heavy flavor tagging capabilities with the installation of a silicon vertex detector (SVX), that will allow precise measurements of secondary decay vertices in the plane transverse to the beam (impact parameter resolution {approx equal} 12 {mu}m). We expect this detector to have a significant impact on b-physics (c{tau}{sub B} {approx equal} 350 {mu}m) and top search. In the following we will discuss CDF prospects for top search and for CP v… more
Date: September 1, 1991
Creator: Dell'Agnello, S.
Partner: UNT Libraries Government Documents Department
open access

Stark broadening of isolated lines from high-Z emitters in dense plasmas

Description: The joint distribution of the electric microfield and its longitudinal derivative is required for the calculation of line profiles for the He-like ions in very dense plasmas. We used a molecular dynamics code to compute exact distributions in single- and multi-component plasmas, and then we investigated various analytical approximations to these results. We found that a simplified, two-nearest-neighbor scheme leads to surprisingly accurate distribution functions. Our results are illustrated by … more
Date: September 1, 1980
Creator: Weisheit, J.C. & Pollock, E.L.
Partner: UNT Libraries Government Documents Department
open access

Automatic program timing profiles with FTN4

Description: Design of a scheme for producing execution timing profiles of FORTRAN programs automatically is proposed with a recommendation to implement it as an option to the compiler. An experimental implementation on the LBL 7600 is also described. 1 figure.
Date: September 1, 1980
Creator: Friedman, R.
Partner: UNT Libraries Government Documents Department
open access

Performance and development of dE/dx counters

Description: The performance of existing or nearly completed detectors for particle identification by using the relativistic rise of energy loss will be discussed. Detailed analysis of systematic errors leads finally to large detector systems approaching the ultimate resolution as measured in small test devices. New methods for extracting the information from the counter with the potential of better particles separation than standard dE/dx will be presented. It includes very fine sampling, delta-ray clippin… more
Date: September 1, 1980
Creator: Walenta, A. H.
Partner: UNT Libraries Government Documents Department
open access

Detectors for radiation dosimetry

Description: For our purposes in this review, we note the following points: (1) for charged particle detection, these counters can be filled with any noble gas-quenching gas mixture that produces satisfactory electrical signals; (2) neutron counters, in which the neutrons are detected by their interaction with the specific filling of the chamber to yield an ionizing particle, require special gas mixtures containing /sup 3/He or BF/sub 3/, an alternative approach is to coat the inner surface of the cathode w… more
Date: September 1, 1979
Creator: Perez-Mendez, V.
Partner: UNT Libraries Government Documents Department
open access

Dilepton (e sup + e sup minus ) production recent pp and pd studies with DLS at Berkeley

Description: The use of dileptons as probes of hot, dense hadronic matter is described. Preliminary results on dileptons produced in p-p and p-d interactions at the Bevalac are presented along with potential ramifications for existing model calculations of dileptons at these energies. Future directions of the dilepton program at Berkeley are outlined. 14 refs., 3 figs.
Date: September 1, 1991
Creator: Schroeder, L. S.
Partner: UNT Libraries Government Documents Department
open access

Techniques for preventing damage to high power laser components

Description: Techniques for preventing damage to components of the LASL Shiva high power laser system were briefly presented. Optical element damage in the disk amplifier from the combined fluence of the primary laser beam and the Xenon flash lamps that pump the cavity was discussed. Assembly and cleaning techniques were described which have improved optical element life by minimizing particulate and optically absorbing film contamination on assembled amplifier structures. A Class-100 vertical flaw clean ro… more
Date: September 1, 1977
Creator: Stowers, Irving F.; Patton, Howard G.; Jones, Walter A. & Wentworth, Donald E.
Partner: UNT Libraries Government Documents Department
open access

Making sense of anomalous gauge theories

Description: An anomalous gauge theory is defined here as a gauge theory in which the field equation is inconsistent and gauge invariance is lost. A conventional approach to anomalous gauge theories, that of adjusting the fermion content so the anomaly vanishes, is discussed, followed by a mathematically coherent frame for anomalies. 10 refs. (LEW)
Date: September 1, 1985
Creator: Jackiw, R.
Partner: UNT Libraries Government Documents Department
open access

Polarization spectroscopy of tokamak plasmas

Description: Measurements of polarization of spectral lines emitted by tokamak plasmas provide information about the plasma internal magnetic field and the current density profile. The methods of polarization spectroscopy, as applied to the tokamak diagnostic, are reviewed with emphasis on the polarimetry of motional Stark effect in hydrogenic neutral beam emissions. 25 refs., 7 figs.
Date: September 1, 1991
Creator: Wroblewski, D.
Partner: UNT Libraries Government Documents Department
open access

Physical protection solutions for security problems at nuclear power plants. [PWR; BWR]

Description: Under Department of Energy sponsorship, Sandia National Laboratories has developed a broad technological base of components and integrated systems to address security concerns at facilities of importance, including nuclear reactors. The primary security concern at a light water reactor is radiological sabotage, a deliberate set of actions at a plant which could expose the public to a significant amount of radiation (on the order of 10 CFR 100 limits). (Also of importance to plant operators are … more
Date: September 1, 1980
Creator: Darby, J.L. & Jacobs, J.
Partner: UNT Libraries Government Documents Department
open access

A prototype on-line work procedure system for radioisotope thermoelectric generator production

Description: An on-line system to manage work procedures is being developed to support radioisotope thermoelectric generator (RTG) assembly and testing in a new production facility. This system implements production work procedures as interactive electronic documents executed at the work site with no intermediate printed form. It provides good control of the creation and application of work procedures and provides active assistance to the worker in performing them and in documenting the results. An extensiv… more
Date: September 1, 1991
Creator: Kiebel, G.R.
Partner: UNT Libraries Government Documents Department
open access

Panel discussion on laboratory accelerator programs: present and future

Description: The present SLAC accelerator program is summarized briefly, and the future of electron-positron colliders is discussed. Present activities discussed include the PEP storage ring, the SPEAR storage ring, the Linear Accelerator, and the SLAC Linear Collider (SLC) project. Future prospects include a larger scale linear collider. The stability requirements on acceleration are briefly discussed. (LEW)
Date: September 1, 1986
Creator: Richter, B.
Partner: UNT Libraries Government Documents Department
open access

Ferrocyanide-containing waste tanks: Ferrocyanide chemistry and reactivity

Description: The complexing constant for hexacyano-iron complexes, both Fe(2) and Fe(3), are exceptionally large. The derived transition metal salts or double salts containing alkali metal ions are only slightly soluble. The various nickel compounds examined in this study, i.e., those predicted to have been formed in the Hanford waste scavenging program, are typical examples. In spite of their relative stability towards most reagents under ambient conditions, they are all thermodynamically unstable towards … more
Date: September 1, 1991
Creator: Scheele, R. D.; Burger, L. L.; Tingey, J. M.; Bryan, S. A.; Borsheim, G. L.; Simpson, B. C. et al.
Partner: UNT Libraries Government Documents Department
open access

Search for W prime and Z prime at CDF

Description: We have searched for heavy charged and neutral vector bosons via the decays W{prime} {yields} ev, W{prime} {yields} {mu}v, Z{prime} {yields} {mu}{mu} in p{bar p} collisions at {radical}s = 1.8 TeV, using data taken with the collider Detector at Fermilab. The nonobservation of these processes leads to a lower limit (95% confidence level) of 520 GeV/c{sup 2} on the mass of the W{prime} and of 412 GeV/C{sup 2} on the mass of the Z{prime}, assuming standard model coupling to fermions. 12 refs., 6 f… more
Date: September 1, 1991
Creator: Fuess, T.
Partner: UNT Libraries Government Documents Department
open access

The Scalable Coherent Interface and related standards projects

Description: The Scalable Coherent Interface (SCI) project (IEEE P1596) found a way to avoid the limits that are inherent in bus technology. SCI provides bus-like services by transmitting packets on a collection of point-to-point unidirectional links. The SCI protocols support cache coherence in a distributed-shared-memory multiprocessor model, message passing, I/O, and local-area-network-like communication over fiber optic or wire links. VLSI circuits that operate parallel links at 1000 MByte/s and serial … more
Date: September 1, 1991
Creator: Gustavson, D.B.
Partner: UNT Libraries Government Documents Department
open access

Open and hidden charm muoproduction. [209 GeV]

Description: New results are presented on open and hidden charm and bottom production by 209-GeV muons interacting in a magnetized steel calorimeter. The upper limit on the production of T states by muons is sigma(..mu..N ..-->.. ..mu..UPSILONX)B(UPSILON ..-->.. ..mu mu..) < 22 x 10/sup -39/ cm/sup 2/ (90% confidence level). The distributions of elastically produced psi's are consistent with s-channel helicity conservation (SCHC) and disagree with psi dominance. From analysis of dimuon final states the cros… more
Date: September 1, 1980
Creator: Clark, A.R.; Johnson, K.J. & Kerth, L.T.
Partner: UNT Libraries Government Documents Department
open access

Bootstrap and fast wave current drive for tokamak reactors

Description: Using the multi-species neoclassical treatment of Hirshman and Sigmar we study steady state bootstrap equilibria with seed currents provided by low frequency (ICRF) fast waves and with additional surface current density driven by lower hybrid waves. This study applies to reactor plasmas of arbitrary aspect ratio. IN one limit the bootstrap component can supply nearly the total equilibrium current with minimal driving power (< 20 MW). However, for larger total currents considerable driving power… more
Date: September 1, 1991
Creator: Ehst, D.A.
Partner: UNT Libraries Government Documents Department
open access

Nuclear de-excitation processes following medium energy heavy ion collisions

Description: As heavy ion reaction studies have progressed from beam energies below 10 MeV/nucleon to higher energies, many non-equilibrium reaction phenomena have been observed. Among these are nucleon emission with velocities in excess of the beam velocity, incomplete momentum transfer to evaporation residue and fission-like fragments, ..gamma..-rays with energies in excess of 100 MeV, and ..pi../sup 0/ production when beam energies are below the threshold for production by the nucleon-nucleon collision m… more
Date: September 1, 1986
Creator: Blann, M.
Partner: UNT Libraries Government Documents Department
open access

Operational history of Fermilab's 1500 W refrigerator used for energy saver magnet production testing

Description: The 1500 W helium refrigerator system utilizes two oil-injected screw compressors staged to feed a liquid nitrogen pre-cooled cold box. Refrigeration is provided by two Sulzer TGL-22 magnetic/gas bearing turbines. The refrigerator feeds six magnet test stands via a 10,000 L dewar and subcooler equipped distribution box. The design of the controls has permitted the system to be routinely operated 24 hours/day, seven days/week with only five operators. It has operated approximately 90% of the 4-1… more
Date: September 1, 1985
Creator: Bianchi, A. J.; Barger, R. K.; Johnson, F. B.; McGuire, K. J.; Pinyan, K. D.; Wilson, F. W. et al.
Partner: UNT Libraries Government Documents Department
open access

Positron computed tomography: current state, clinical results and future trends

Description: An overview is presented of positron computed tomography: its advantages over single photon emission tomography, its use in metabolic studies of the heart and chemical investigation of the brain, and future trends. (ACR)
Date: September 1, 1980
Creator: Schelbert, H. R.; Phelps, M. E. & Kuhl, D. E.
Partner: UNT Libraries Government Documents Department
open access

Polymer concrete patching materials

Description: The increased use of deicing salts is causing rapid deterioration of portland cement concrete bridge decks. Soluble chlorides cause corrosion of the steel reinforcing rods with a corresponding increase in volume of the rods. This expansion causes stresses in the concrete which result in delaminations and surface spalling. The repair of surface spalls with portland cement concrete can only be made if traffic can be avoided for several days. A patching material which would allow traffic to resume… more
Date: September 1, 1977
Creator: Fontana, J.J.
Partner: UNT Libraries Government Documents Department
open access

Pellet fueling development at ORNL

Description: Advanced plasma fueling systems for magnetic confinement devices are being developed at the Oak Ridge National Laboratory (ORNL). The general approach is that of producing and accelerating frozen hydrogenic pellets at speeds in the range of 1-2 km/s and higher. Two specific concepts are under development: (1) high-speed pneumatic acceleration; and (2) mechanical (centrifugal) acceleration. Both approaches are being pursued to meet the projected pellet size and delivery rates for major near-term… more
Date: September 1, 1986
Creator: Combs, S. K.; Milora, S. L.; Foster, C. A.; Schuresko, D. D.; Foust, C. R.; Simmons, D. W. et al.
Partner: UNT Libraries Government Documents Department
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