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Mechanism of strain release in carbon nanotubes

Description: Article on the mechanism of strain release in carbon nanotubes.
Date: February 15, 1998
Creator: Buongiorno Nardelli, Marco; Yakobson, Boris I. & Bernholc, Jerry
Partner: UNT College of Arts and Sciences
open access

Evaluating Alternative Responses to Safeguards Alarms

Description: This paper describes a quantitative approach to help evaluate and respond to safeguards alarms. These alarms may be generated internally by a facility's safeguards systems or externally by individuals claiming to have stolen special nuclear material (SNM). This approach can be used to identify the most likely cause of an alarm - theft, hoax, or error - and to evaluate alternative responses to alarms. Possible responses include conducting investigations, initiating measures to recover stolen SNM… more
Date: April 15, 1982
Creator: Al-Ayat, R. A.; Judd, B. R. & McCord, R. K.
Partner: UNT Libraries Government Documents Department
open access

Field reversed mirror reactor

Description: The parametric analysis and preliminary conceptual design for a multicell field reversed mirror reactor (FRM) are described.
Date: November 15, 1977
Creator: Carlson, G. A.; Condit, W. C.; Devoto, R. S. & Neef, W. S.
Partner: UNT Libraries Government Documents Department
open access

Current status of fast-neutron-capture calculations

Description: This work is primarily concerned with the calculation of neutron capture cross sections and capture gamma-ray spectra, in the framework of the Hauser-Feshbach statistical model and for neutrons from the resonance region up to several MeV. An argument is made that, for applied purposes such as constructing evaluated cross-section libraries, nonstatistical capture mechanisms may be completely neglected at low energies and adequately approximated at high energies in a simple way. The use of gamma-… more
Date: April 15, 1982
Creator: Gardner, D. G.
Partner: UNT Libraries Government Documents Department
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Space propulsion by fusion in a magnetic dipole

Description: The unique advantages of fusion rocket propulsion systems for distant missions are explored using the magnetic dipole configurations as an example. The dipole is found to have features well suited to space applications. Parameters are presented for a system producing a specific power of kW/kg, capable of interplanetary flights to Mars in 90 days and to Jupiter in a year, and of extra-solar-system flights to 1000 astronomical units (the Tau mission) in 20 years. This is about 10 times better spe… more
Date: July 15, 1991
Creator: Teller, E.; Glass, A.J.; Fowler, T.K. (Lawrence Livermore National Lab., CA (United States)); Hasegawa, A. (AT and T Bell Labs., Murray Hill, NJ (United States)) & Santarius, J.F. (Wisconsin Univ., Madison, WI (United States). Fusion Technology Inst.)
Partner: UNT Libraries Government Documents Department
open access

Safety questions relevant to nuclear thermal propulsion

Description: Nuclear propulsion is necessary for successful Mars exploration to enhance crew safety and reduce mission costs. Safety concerns are considered by some to be an implements to the use of nuclear thermal rockets for these missions. Therefore, an assessment was made of the various types of possible accident conditions that might occur and whether design or operational solutions exist. With the previous work on the NERVA nuclear rocket, most of the issues have been addressed in some detail. Thus, a… more
Date: October 15, 1991
Creator: Buden, D.
Partner: UNT Libraries Government Documents Department
open access

LLL calibration and standards facility

Description: The capabilities of Lawrence Livermore Laboratory's Calibration and Standards Facility are delineated. The facility's ability to provide radiation fields and measurements for a variety of radiation safety applications and the available radiation measurement equipment are described. The need for national laboratory calibration labs to maintain traceability to a national standard are discussed as well as the areas where improved standards and standardization techniques are needed.
Date: April 15, 1980
Creator: Campbell, G.W. & Elliott, J.H.
Partner: UNT Libraries Government Documents Department
open access

Detailed photonuclear cross-section calculations and astrophysical applications

Description: We have investigated the role of an isomeric state and its coupling to the ground state (g.s.) via photons and neutron inelastic scattering in a stellar environment by making detailed photonuclear and neutron cross-section calculations for /sup 176/Lu and /sup 210/Bi. In the case of /sup 176/Lu, the g.s. would function as an excellent galactic slow- (s-) process chronometer were it not for the 3.7-h isomer at 123 keV. Our calculations predicted much larger photon cross sections for production o… more
Date: June 15, 1989
Creator: Gardner, D. G.; Gardner, M. A. & Hoff, R. W.
Partner: UNT Libraries Government Documents Department
open access

Large scale copper vapor laser computer control system

Description: High power pulse copper vapor laser systems consist of a master oscillator and numerous power amplifiers. Large systems used in laser isotope separation experiments require several automatic control systems. The rapid development of compact mini computers over the past several years has enabled the implementation of sophisticated computer controlled copper vapor laser systems. Present systems provide automatic time synchronization and input power stabilization. Future systems will incorporate s… more
Date: May 15, 1979
Creator: LaChapell, M. J.; Spencer, L. W. & Coutts, G. W.
Partner: UNT Libraries Government Documents Department
open access

Liquid nitrogen cooling considerations of the compact ignition tokamak

Description: An analytical procedure was developed to estimate the cooldown time between pulses of the Compact Ignition Tokamak (CIT) utilizing liquid nitrogen. Fairly good agreement was obtained between the analysis results and those measured in the early fusion experimental devices. The cooldown time between pulses in the CIT is controlled by the energy disposition in the inner leg of the TF coil. A cooldown time of less than one hour is feasible for the CIT if fins are used in the cooling channels. An R … more
Date: June 15, 1986
Creator: Dabiri, A. E.
Partner: UNT Libraries Government Documents Department
open access

The industrial consortium for the utilization of the geopressured-geothermal resource

Description: Four feasibility studies have been developed by the INEL on thermal enhanced oil recovery (TEOR) Use of Supercritical Fluid processes for Detoxification of Pollutants, and Hydraulic Conversion to Electricity, and Direct Use. The studies provide information bases for potential industrial partners in the resource utilization. A joint proposal from Los Alamos National Laboratory (LANL) and INEL on supercritical fluid processes in going forward. Western Resources Technology has begun development of… more
Date: February 15, 1991
Creator: Negus-de Wys, J.
Partner: UNT Libraries Government Documents Department
open access

Production of eta mesons in e/sup +/e/sup -/ annihilations at. sqrt. s = 29 GeV

Description: Data from e/sup +/e/sup -/ annihilations at 29 GeV have been used to measure the production and fragmentation of eta mesons. The signal is observed in the eta ..-->.. ..gamma gamma.. decay channel. The fragmentation function for p/sub eta/ > 1.5 GeV/c agrees well with the shapes predicted by both the Lund and Webber models. However, the mean multiplicity is measured to be < n/sub eta/ > = 0.37 +- 0.08 eta mesons per hadronic annihilation event, which is significantly lower than the values predi… more
Date: June 15, 1987
Creator: Abachi, S.; Akerlof, C.; Baringer, P.; Blockus, D.; Brabson, B.; Brom, J.M. et al.
Partner: UNT Libraries Government Documents Department
open access

Improved Approach to Characterizing and Presenting Streak Camera Performance

Description: The performance of a streak camera recording system is strongly linked to the technique used to amplify, detect and quantify the streaked image. At the Lawrence Livermore National Laboratory (LLNL) streak camera images have been recorded both on film and by fiber-optically coupling to charge-coupled devices (CCD's). During the development of a new process for recording these images (lens coupling the image onto a cooled CCD) the definitions of important performance characteristics such as resol… more
Date: July 15, 1985
Creator: Wiedwald, J. D. & Jones, B. A.
Partner: UNT Libraries Government Documents Department
open access

THz radiation as a bunch diagnostic forlaser-wakefield-accelerated electron bunches

Description: Experimental results are reported from two measurementtechniques (semiconductor switching and electro-optic sampling) thatallow temporal characterization of electron bunches produced by alaser-driven plasma-based accelerator. As femtosecond electron bunchesexit the plasma-vacuum interface, coherent transition radiation (at THzfrequencies) is emitted. Measuring the properties of this radiationallows characterization of the electron bunches. Theoretical work on theemission mechanism is represente… more
Date: February 15, 2006
Creator: van Tilborg, J.; Schroeder, C. B.; Filip, C. V.; Toth, Cs.; Geddes, C. G. R.; Fubiani, G. et al.
Partner: UNT Libraries Government Documents Department
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