89 Matching Results

Search Results

Results: 1 - 24 next
open access

Intelligent optical design program

Description: Described is a general approach to the development of computer programs capable of designing image-forming optical systems without human intervention and of improving their performance with repeated attempts. The approach utilizes two ideas: (1) interpretation of technical design as a mapping in the configuration space of technical characteristics and (2) development of an intelligent routine that recognizes global optima. Examples of lens systems designed and used in the development of the gen… more
Date: May 4, 1984
Creator: Bohachevsky, I.O.; Viswanathan, V.K. & Woodfin, G.
Partner: UNT Libraries Government Documents Department
open access

Surface modification of solids

Description: The use of ion beam and pulsed laser processing is reviewed for the near-surface modification of a wide range of materials. The techniques of ion implantation doping, ion beam and laser mixing, and pulsed-laser annealing are stressed with particular emphasis on the nonequilibrium aspects of these processing techniques and on new materials properties which can result. Examples are presented illustrating the utility of these techniques for fundamental materials research as well as practical surfa… more
Date: May 1, 1984
Creator: Appleton, B. R.
Partner: UNT Libraries Government Documents Department
open access

3-D treatment of convective flow in the earth's mantle

Description: A three-dimensional finite-element method is used to investigate thermal convection in the earth's mantle. The equations of motion are solved implicitly by means of a fast multigrid technique. The computational mesh for the spherical problem is derived from the regular icosahedron. The calculation described use a mesh with 43,554 nodes and 81,920 elements and were run on a Cray X. The earth's mantle is modeled as a thick spherical shell with isothermal, free-slip boundaries. The infinite Prandt… more
Date: May 1, 1984
Creator: Baumgardner, J.R.
Partner: UNT Libraries Government Documents Department
open access

Crossed undulator system for a variable polarization synchrotron radiation source

Description: A crossed undulator system can produce synchrotron radiation whose polarization is arbitrary and adjustable. The polarization can be linear and modulated between two mutually perpendicular directions, or it can be circular and can be modulated between right and left circular polarizations. The system works on low emittance electron storage rings and can cover a wide spectral range. Topics discussed include the basic principle of the system, the design equations and the limitations in performanc… more
Date: May 1, 1984
Creator: Kim, K. J.
Partner: UNT Libraries Government Documents Department
open access

Focusing twist reflector for electron-cyclotron resonance heating in the Tandem Mirror Experiment-Upgrade

Description: A twist reflector plate is described that linearly polarizes and focuses the TE/sub O/sub 1// circular waveguide mode for heating hot electrons in the thermal barrier of the Tandem Mirror Experiment-Upgrade (TMX-U). The plate polarizing efficiency is 95%, and it has operated satisfactorily at 150 kW power level.
Date: May 1, 1984
Creator: Stallard, B.W.; Coffield, F.E.; Felker, B.; Taska, J.; Christensen, T.E.; Gallagher, N.C. Jr. et al.
Partner: UNT Libraries Government Documents Department
open access

Charge-changing collisions

Description: Recent results for charge-changing collisions of interest for cyclotrons and other particle accelerators are presented. Scaling rules, where available, are emphasized. 45 references, 11 figures.
Date: May 1, 1984
Creator: Schlachter, A.S.
Partner: UNT Libraries Government Documents Department
open access

Analyzing power measurements in high-P/sub perpendicular to//sup 2/ p-p elastic scattering

Description: The analyzing power in 28 GeV/c proton-proton elastic scattering was measured at P/sub perpendicular to//sup 2/ = 5.95 and 6.56 (GEV/c)/sup 2/ y/sub g/ a polarized proton target and an unpolarized proton beam at the Brookhaven National Laboratory AGS. Results indicate that the analyzing power, A, is rising sharply with P/sub perpendicular to//sup 2/. Previous measurements of the analyzing power, A, in p + p ..-->.. p + p suggested a rise in A at large-P/sub perpendicular to//sup 2/, but the sta… more
Date: May 23, 1984
Creator: Raymond, R. S.; Brown, K. A.; Bruni, R. J.; Cameron, P. R.; Crabb, D. G.; Cummings, R. L. et al.
Partner: UNT Libraries Government Documents Department
open access

Operational parameters of a 2. 0-MeV RFQ linac

Description: After extensive upgrading, our radio-frequency quadrupole (RFQ) linac is again installed on the accelerator test stand (ATS). The measured parameters of the RFQ, such as the output transverse emittance, transmitted beam, average energy, and energy spread is presented.
Date: May 7, 1984
Creator: Sander, O. R.; Purser, F. O. & Rusthoi, D. P.
Partner: UNT Libraries Government Documents Department
open access

Hadron production in e/sup +/e/sup -/ annihilation at PEP

Description: Recent results from PEP on quark and gluon fragmentation are reviewed. Topics include: inclusive stable particle production and resonance production, particle distributions in jets, heavy quark fragmentation, flavor correlation studies and tests of fragmentation models. 37 references.
Date: May 1, 1984
Creator: Hofmann, W.
Partner: UNT Libraries Government Documents Department
open access

Ep option at the SSC

Description: The possibilities for colliding electrons with the 20 TeV proton beams of the SSC are considered. Kinematics of ep colliding beams is reviewed. Energies that may be possible and interesting are suggested, and detector problems associated with the highly imbalanced collisions are briefly considered.
Date: May 1, 1984
Creator: Prescott, Charles Y.
Partner: UNT Libraries Government Documents Department
open access

Quantum chromodynamic evolution of multiquark systems

Description: We present a new technique which extends the quantum chromodynamic evolution formalism in order to predict the short distance behavior of multiquark wavefunctions. In particular, predictions are given for the deuteron reduced form factor in the high momentum transfer region, and rigorous constraints on the short distance effective force between two baryons are predicted. These new techniques can be generalized in order to analyze the short distance behavior of multibaryon systems.
Date: May 1, 1984
Creator: Ji, C.R. & Brodsky, S.J.
Partner: UNT Libraries Government Documents Department
open access

Momentum distributions in hcp, bcc, and liquid /sup 4/He

Description: Using Deep Inelastic Neutron Scattering we have measured the nuclear momentum distribution in hcp, bcc and liquid /sup 4/He at constant density over a temperature range 0.96K < T < 4.0K. We find no temperature dependence of the momentum distribution in the hcp solid or the liquid. We also find no difference between the hcp, bcc and liquid phases. The average kinetic energy per atom is lower than the best present theories predict.
Date: May 1, 1984
Creator: Sokol, P.E.; Simmons, R.O.; Price, D.L. & Hilleke, R.O.
Partner: UNT Libraries Government Documents Department
open access

Design and operation of the LBL heavy ion RFQ linac

Description: LBL has designed and tested a heavy ion RFQ linac for ions in the mass range of 1 to 40. Designed as part of a preinjector package for synchrotron applications, it is a low duty factor device, operating at 200 MHz with maximum surface fields as high as 28 MV/meter. It is a loop-driven, four vane structure employing several innovative design concepts. These include an exit matcher section, to ensure efficient capture by a following Alvarez linac; advanced mechanical design features, to ensure ac… more
Date: May 1, 1984
Creator: Gouch, R.A.
Partner: UNT Libraries Government Documents Department
open access

Uranium resources and their implications for fission breeder and fusion hybrid development

Description: Present estimates of uranium resources and reserves in the US and the non-Communist world are reviewed. The resulting implications are considered for two proposed breeder technologies: the liquid metal fast breeder reactor (LMFBR) and the fusion hybrid reactor. Using both simple arguments and detailed scenarios from the published literature, conditions are explored under which the LMFBR and fusion hybrid could respectively have the most impact, considering both fuel-supply and economic factors.… more
Date: May 15, 1984
Creator: Max, C.E.
Partner: UNT Libraries Government Documents Department
open access

Early operating experience with the Brookhaven National Laboratory radio frequency quadrupole accelerator

Description: The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole (RFQ) for acceleration between the polarized H/sup -/ source and the Alvarez Linac. The RFQ accelerator is now in operation with low beam currents. The results of low and high power rf testing will be reported together with initial results of operation in the polarized H/sup -/ beam line.
Date: May 1, 1984
Creator: Brown, H.; Clifford, T.; Giordano, S.; Khiari, F.; McKenzie-Wilson, R.; Puglisi, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Dynamics of angular momentum accumulation in damped nuclear reactions

Description: The dynamical evolution of the correlated angular momentum distribution in a damped nuclear reaction is discussed within the framework of the nucleon exchange transport model. 13 references.
Date: May 1, 1984
Creator: Randrup, J. & Doessing, T.
Partner: UNT Libraries Government Documents Department
open access

DT-burning upgrade to MFTF-B

Description: To improve MFTF-B, one must raise the ion energy and the electrostatic confining potential. This requires higher beam energy (200 keV in this case) and, to preserve end-plug adiabaticity and hold higher plasma density in the central cell, a higher level of magnetic field. In the MFTF Upgrade we also want to incorporate the new end plug configuration first invented for the MARS reactor. This new magnet design is compared with the present MFTF-B magnet set. The differences include the addition of… more
Date: May 7, 1984
Creator: Thomassen, K. I.; Logan, B. G.; Doggett, J. N. & Coensgen, F. H.
Partner: UNT Libraries Government Documents Department
open access

Status report on the ATLAS superconducting linear accelerator

Description: ATLAS, the Argonne Tandem-Linac Accelerator System, is a project to upgrade the existing Argonne superconducting linac heavy-ion booster which began providing beams of heavy-ions for experimental nuclear research in 1979. When completed ATLAS will provide beams of heavy ions up to approximately mass 130 at energies as high as 25 MeV/A. The construction of ATLAS is approximately 60% complete. First beam from the accelerator is expected in spring of 1985.
Date: May 1, 1984
Creator: Argon, J.; Benaroya, R.; Bogaty, J.; Bollinger, L. M.; Clifft, B. E.; Den Hartog, P. et al.
Partner: UNT Libraries Government Documents Department
open access

Computational method for realistic estimates of the dose to active marrow

Description: Calculation of absorbed dose to active marrow from photon radiation is a complex problem because electronic equilibrium may not exist in the vicinity of soft tissue-bone mineral interfaces. Snyder et al. recognized the intractable geometry of trabecular bone in their studies of photon transport in the body and formulated marrow dose estimates in a conservative manner. Other investigators have noted that this approach leads to overestimate by factors of 3 or more at low photon energy. In this pa… more
Date: May 11, 1984
Creator: Eckerman, K.F. & Cristy, M.
Partner: UNT Libraries Government Documents Department
open access

Logging technology for high-temperature geothermal boreholes

Description: Research in materials, equipment, and instrument development was required in the Hot Dry Rock Energy Extraction Demonstration at Fenton Hill located in northern New Mexico. Results of this extensive development advanced the logging technology in geothermal boreholes to present state-of-the art. The new Phase II Energy Extraction System at the Fenton Hill Test Site will consist of two wellbores drilled to a depth of about 4570 m (15,000 ft) and then connected by a series of hydraulic-induced fra… more
Date: May 1, 1984
Creator: Dennis, B.R.
Partner: UNT Libraries Government Documents Department
open access

Electron cyclotron resonance (ECR) ion sources

Description: Starting with the pioneering work of R. Geller and his group in Grenoble (France), at least 14 ECR sources have been built and tested during the last five years. Most of those sources have been extremely successful, providing intense, stable and reliable beams of highly charged ions for cyclotron injection or atomic physics research. However, some of the operational features of those sources disagreed with commonly accepted theories on ECR source operation. To explain the observed behavior of a… more
Date: May 1, 1984
Creator: Jongen, Y.
Partner: UNT Libraries Government Documents Department
open access

Workshop on electronic and ionic collision cross sections needed in the modeling of radiation interactions with matter: proceedings

Description: The term modeling in the Workship title refers to the mathematical analysis of the consequences of many collision processes for characterizing the physical stage of radiation actions. It requires as input some knowledge of collision cross sections. Traditionally, work on cross sections and work on the modeling are conducted by separate groups of scientists. It was the purpose of the Workshop to bring these two groups together in a forum that would promote effective communication. Cross-section … more
Date: May 1, 1984
Partner: UNT Libraries Government Documents Department
open access

ASP: a new PEP experiment to measure single photons

Description: The design and construction of a new experiment for PEP designed to measure the flux of low energy photons unaccompanied by any additional photons, or charged tracks is described. The device consists of arrays of extruded lead glass bars and PWC's in the central region with lead-scintillator shower counters, drift chambers and PWC's in the forward regions. 9 references.
Date: May 1, 1984
Creator: Hollebeek, R.
Partner: UNT Libraries Government Documents Department
open access

Theories of fermion masses

Description: We present grand unified theories in which the quark masses and mixing angles are calculated in terms of the lepton masses through simple group theory. The theories contain no small Yukawa couplings. A favored value of the top quark mass is 35 GeV.
Date: May 1, 1984
Creator: Bagger, J.; Dimopoulos, S.; Georgi, H. & Raby, S.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen