N = 2 Maxwell-Einstein Supergravity Theories: Their Compact and Non-Compact Gaugings and Jordan Algebras (open access)

N = 2 Maxwell-Einstein Supergravity Theories: Their Compact and Non-Compact Gaugings and Jordan Algebras

In this talk we give a review of our work on the construction and classification of N = 2 Maxwell-Einstein Supergravity theories (MESGT), study of the underlying algebraical and geometrical structure of these theories, and their compact and non-compact gaugings. We begin by summarizing our construction of the N = 2 MESGT's in five dimensions and give a geometrical interpretation to various scalar dependent quantities in the Lagrangian, based on the constraiants implied by supersymmetry. This is followed by a complete classification of the N = 2 MESGT's whose target manifolds parametrized by the scalar fields are symmetric spaces. 39 refs.
Date: January 1, 1985
Creator: Guenaydin, M.; Sierra, G. & Townsend, P.K.
Object Type: Article
System: The UNT Digital Library
10-MHz high-voltage modulator with pulse-width and repetition-rate agility (open access)

10-MHz high-voltage modulator with pulse-width and repetition-rate agility

Requirements for control and rapid switching of the proton beam at the Los Alamos Meson Physics Facility (LAMPF) are continually revised to support accelerator upgrades and modifications. A recent upgrade required the development of a 10-MHz high-voltage modulator for an electrostatic kicker with real-time control of pulse width and repetition rate over a range of four decades. The modulator must be capable of producing a voltage pulse across a capacitive load with a rise time of less than or equal to20 ns (10% to 90%). In addition the falling edge undershoot must be controlled to less than one part in 10/sup 3/. The paper describes in detail the circuit design philosophy, layout, and critical areas in system design.
Date: January 1, 1985
Creator: Krausse, G.J.
Object Type: Article
System: The UNT Digital Library
20 keV undulators for a 6-GeV storage ring (open access)

20 keV undulators for a 6-GeV storage ring

The main goal of the future 6-GeV electron storage ring is to provide 20-keV fundamental harmonic radiations from insertion devices. Parameter restrictions of REC-vanadium permendur hybrid undulators have been examined. The critical factor is the achievable minimum gap of the undulator. Variations of the spectral brilliance for different beam parameters are also shown. 6 refs., 5 figs.
Date: January 1, 1985
Creator: Kim, S. H. & Cho, Y.
Object Type: Article
System: The UNT Digital Library
32-Bit computer for large memory applications on FASTBUS (open access)

32-Bit computer for large memory applications on FASTBUS

A FASTBUS based 32-bit computer is being built at Los Alamos National Laboratory for use in systems requiring large fast memory in the FASTBUS environment. A separate local execution bus allows data reduction to proceed concurrently with other FASTBUS operations. The computer, which can operate in either master or slave mode, includes the National Semiconductor NS32032 chip set with demand paged memory management, floating point slave processor, interrupt control unit, timers, and time-of-day clock. The 16.0 megabytes of random access memory are interleaved to allow windowed direct memory access on and off the FASTBUS at 80 megabytes per second.
Date: January 1, 1985
Creator: Blossom, J. M.; Hong, J. P. & Kellner, R. G.
Object Type: Article
System: The UNT Digital Library
32-Bit FASTBUS computer (open access)

32-Bit FASTBUS computer

Los Alamos National Laboratory is building a 32-bit FASTBUS computer using the NATIONAL SEMICONDUCTOR 32032 central processing unit (CPU) and containing 16 million bytes of memory. The board can act both as a FASTBUS master and as a FASTBUS slave. It contains a custom direct memory access (DMA) channel which can perform 80 million bytes per second block transfers across the FASTBUS.
Date: January 1, 1985
Creator: Blossom, J.M.; Hong, J.P. & Kellner, R.G.
Object Type: Article
System: The UNT Digital Library
1500-MeV fixed-field alternating-gradient synchrotron for a pulsed-spallation neutron source (open access)

1500-MeV fixed-field alternating-gradient synchrotron for a pulsed-spallation neutron source

The first conceptual design of the FFAG for ASPUN was an 1100-MeV, 20-sector machine with an injection radius of 17.5 m and an extraction radius of 18.75 m. The conceptual design currently under study has a higher extraction energy, a larger average radius, but still has 20 sectors. The current interest in higher extraction energy is stimulated by calculations that indicate that the useful neutron production per incident proton is still increasing proportionally up to 1500 MeV. The larger radius also matches existing buildings at Argonne that could be made available for the facility. 11 refs., 4 figs., 3 tabs.
Date: January 1, 1985
Creator: Kustom, R.L.; Khoe, T.K. & Crosbie, E.A.
Object Type: Article
System: The UNT Digital Library
1983 ORNL intercomparison of personnel neutron and gamma dosemeters (open access)

1983 ORNL intercomparison of personnel neutron and gamma dosemeters

The Ninth Personnel Dosimetry Intercomparison Study was conducted during April 19-21, 1983, at the Oak Ridge National Laboratory. Dosemeters from 33 participating agencies were mounted on water-filled polyethylene elliptical phantoms and exposed to a range of low-level dose equivalents (0.02-0.45 mSv gamma and 0.49-11.14 mSv neutron) which could be encountered during routine personnel monitoring in mixed radiation fields. The Health Physics Research Reactor served as the radiation source for six separate exposures which used four different shield conditions: unshielded and shielded with steel, steel/concrete, and concrete. Results of the neutron measurements indicate that it is not unusual for dose equivalent estimates made under the same conditions by different agencies to differ by more than a factor of 2. Albedo systems, which were the most popular neutron monitors in this study, provided the most accurate results with CR-39 recoil track being least accurate. Track and film neutron systems exhibited problems providing measurable indication of neutron exposure at dose equivalents of about 0.50 mSv. Gamma measurements showed that TLD and film systems generally overestimated dose equivalents in the mixed radiation fields with film exhibiting significant problems providing measurable indication of gamma exposure at dose equivalents lower than about 0.15 mSv. Under the …
Date: January 1, 1985
Creator: Swaja, R. E.; Sims, C. S. & Greene, R.T.
Object Type: Report
System: The UNT Digital Library
2D ACAR momentum density study of the nature of the positron surface state on Al(100) (open access)

2D ACAR momentum density study of the nature of the positron surface state on Al(100)

The two-dimensional angular correlation of the 2..gamma.. annihilation radiation (2D ACAR) has been measured from an Al(100) surface bombarded by 200-eV positrons. After removing the contribution of fast para-positronium annihilation, the spectrum from positrons annihilating at the surface exhibits a nearly isotropic conical shape with a (7.1 +- 0.5) mrad FWHM. 5 refs., 6 figs.
Date: January 1, 1985
Creator: Berko, S.; Canter, K. F.; Lynn, K. G.; Mills, A. P.; Roellig, L. O. & West, R. N.
Object Type: Article
System: The UNT Digital Library
3D calculations of a fixed field alternating gradient synchrotron magnet (open access)

3D calculations of a fixed field alternating gradient synchrotron magnet

A Spallation neutron source for materials science studies was designed at Argonne and required a fixed field alternating gradient (FFAG) synchrotron magnet. 3D electrostatic calculations were made to obtain the unsaturated magnet pole shape. This pole shape was refined using 3D magnetostatic calculations that included the steel permeability and coil geometry. Details of the calculations are given concerning such things as: size of the problem and how to split it up, the number and shape of the finite elements, choosing the electrostatic potential correctly and selecting the potential of the desired pole. 5 figs.
Date: January 1, 1985
Creator: Lari, R.J.
Object Type: Article
System: The UNT Digital Library
3lambda/4 post coupler for drift-tube linacs (open access)

3lambda/4 post coupler for drift-tube linacs

New permanent magnets for quadrupole focusing make possible smaller drift tubes in drift-tube linacs (DTLs), resulting in higher shunt impedance. However, ordinary post couplers cannot stabilize a DTL whose drift-tube-to-wall spacing exceeds one-quarter wavelength (lambda/4) by more than a few per cent for the accelerating mode frequency. We have built and tested post couplers that operate in the 3lambda/4 mode. These 3lambda/4 post couplers, when substituted for lambda/4 couplers, had similar stabilization properties. In addition, the coupling between post and drift tube, and the post's resonant frequency can be independently adjusted. 5 refs., 5 figs.
Date: January 1, 1985
Creator: Billen, J. H.; Garcia, J. A.; Potter, J. M. & Spalek, G.
Object Type: Article
System: The UNT Digital Library
4X source (open access)

4X source

Our Penning surface-plasma source (SPS) discharge chamber was enlarged 4X in two dimensions. To date, three pulsed discharge modes have been studied: two with noisy arc (greater than or equal to 20% H/sup -/ current fluctuations) and one with quiescent arc (less than or equal to 1% H/sup -/ current fluctuations). Lower arc magnetic field and higher H/sub 2/ gas flow allow switching from the noisy to the quiescent mode. The noisy modes yield up to 120 mA of 29-keV H/sup -/ beam; for 110 mA at 29 keV, the two-dimensional normalized rms emittance is 0.017 x 0.018 ..pi...cm.mrad. The quiescent mode yields 75 mA of 29-keV H/sup -/beam; for 67 mA at 24 keV, the emittance is 0.011 x 0.012 ..pi...cm.mrad.
Date: January 1, 1985
Creator: Smith, H. Vernon, Jr.; Allison, Paul & Sherman, Joseph D.
Object Type: Article
System: The UNT Digital Library
ABC's of pion charge exchange. [Absorption, blocking, and correlations] (open access)

ABC's of pion charge exchange. [Absorption, blocking, and correlations]

Calculations of pion single charge exchange using the PWIA and DWIA are presented. Emphasis is given to the effects of absorbtion and blocking. A microscopic calculation of the 0/sup 0/ excitation and low energy angular distribution is in excellent agreement with the data. A fixed nucleon multiple scattering calculation of the pion double charge exchange reaction is presented. Various valence neutron wave functions are used, and the contributions of different spatial orientations of the last two neutrons to the reaction are examined. The DCX cross section is found to be very sensitive to the inclusion of correlations in the two-neutron wave function. Satisfactory agreement with DCX data on /sup 14/C can be obtained using a nucleonic picture of the nucleus.
Date: 1985~
Creator: Gibbs, W.R.; Kaufmann, W.B. & Siegel, P.B.
Object Type: Article
System: The UNT Digital Library
Absolute Wavelength Measurement and Fine Structure Determination in /Sup 7/Li Ii (open access)

Absolute Wavelength Measurement and Fine Structure Determination in /Sup 7/Li Ii

The energy levels of two-electron atoms continue to provide rigorous tests of relativistic quantum theory, and of correlation effects within a multi-particle system. These interactions are determined perturbatively, with several approximations, and theoretical results often differ. It is critical to provide precise measurements of absolute wavelengths connecting these atomic energy levels to obtain a resolution of the precision of the different parts of such complex calculations. In this work, we report a high precision optical measurements in the 1s2s /sup 3/S - 1s2p /sup 3/P multiplet of Li II using fast-beam laser spectroscopy. A collinear interaction using both parallel and antiparallel laser and ion beams allows both for precise elimination of large Doppler shifts, and for a strong kinematic narrowing of the observed resonances, as compared with thermal beam experiments. The wavelengths of the observed resonance fluorescence radiation are determined by comparing them with simultaneously recorded saturated absorption profiles of molecular iodine hyperfine components. In turn, the absolute wavelengths of the iodine lines are obtained from precisely calibrated Fabry-Perot etalon fringes in a separate experiment. The final precision of the Li II wavelengths is 5 parts in 10/sup 9/, which is at a level of precision of 80 ppM of …
Date: January 1, 1985
Creator: Riis, E.; Berry, H.G.; Poulsen, O.; Lee, S.A. & Tang, S.Y.
Object Type: Article
System: The UNT Digital Library
Absorption spectra of shocked liquid CS/sub 2/ (open access)

Absorption spectra of shocked liquid CS/sub 2/

The importance of shock initiation of high explosives (HE) was understood as early as 1863 when Alfred Nobel introduced the detonator as a means of detonating nitroglycerine. The critical pressure rise times required to achieve shock initiation and steady propagation of detonation are determined by the chemical and mechanical properties of an explosive. Although progress has been made in the understanding of the effects of mechanical properties, the detailed effects of high pressures on chemical reaction mechanisms are still only poorly understood. This paper reports the results of two experiments using CS/sub 2/, which is known to undergo electronic state transitions when shocked to high pressures. The goal of these experiments was to examine the known shock-generated expansion of CS/sub 2/ absorption bands while generating the shocks with a flyer plate system driven by high explosives.
Date: January 1, 1985
Creator: Dallman, J.C.
Object Type: Article
System: The UNT Digital Library
Acceleration of polarized H/sup -/ in the BNL 200 MeV Linac (open access)

Acceleration of polarized H/sup -/ in the BNL 200 MeV Linac

The AGS Polarized Beam Project was started in 1980. The first beam was accelerated in March 1984, followed by commissioning studies and a high energy physics run at 16.5 GeV at an average 30% polarization. The Linac portion of the project included a new polarized H/sup -/ ion source and a Radio-Frequency Quadrupole (RFQ). These will be described as will the design of the new Low Energy Beam Transport (LEBT) line and beam instrumentation for the Linac. Operational results, current status and future plans will be discussed. 13 refs., 6 figs.
Date: January 1, 1985
Creator: Makdisi, Y.; Witkover, R.; Alessi, J.; Brown, H.; Barton, D.; Kponou, A. et al.
Object Type: Article
System: The UNT Digital Library
Acceleration simulation in the LAMPF II booster (open access)

Acceleration simulation in the LAMPF II booster

We study the evolution of the longitudinal phase space during acceleration from 0.797-7.3 GeV in the LAMPF II booster. This machine is planned to accelerate 150 ..mu..A of protons using a 60 Hz repetition rate. A multiparticle simulation program was used to model the acceleration with space charge included. The bunch population of 2.5 x 10/sup 11/ protons was represented by 1000 macroparticles. During acceleration the rms longitudinal emittance grows by 3% and two particles are lost out of the separatrix. 2 refs., 11 figs., 1 tab.
Date: January 1, 1985
Creator: Colton, E. P.
Object Type: Article
System: The UNT Digital Library
Accelerator breeder nuclear fuel production: concept evaluation of a modified design for ORNL's proposed TME-ENFP (open access)

Accelerator breeder nuclear fuel production: concept evaluation of a modified design for ORNL's proposed TME-ENFP

Recent advances in accelerator beam technology have made it possible to improve the target/blanket design of the Ternary Metal Fueled Electronuclear Fuel Producer (TMF-ENFP), an accelerator-breeder design concept proposed by Burnss et al. for subcritical breeding of the fissile isotope /sup 233/U. In the original TMF-ENFP the 300-mA, 1100-MeV proton beam was limited to a small diameter whose power density was so high that a solid metal target could not be used for producing the spallation neutrons needed to drive the breeding process. Instead the target was a central column of circulating liquid sodium, which was surrounded by an inner multiplying region of ternary fuel rods (/sup 239/Pu, /sup 232/Th, and /sup 238/U) and an outer blanket region of /sup 232/Th rods, with the entire system cooled by circulating sodium. In the modified design proposed here, the proton beam is sufficiently spread out to allow the ternary fuel to reside directly in the beam and to be preceded by a thin (nonstructural) V-Ti steel firThe spread beam mandated a change in the design configuration (from a cylindrical shape to an Erlenmeyer flask shape), which, in turn, required that the fuel rods (and blanket rods) be replaced by fuel pebbles. The …
Date: January 1, 1985
Creator: Johnson, J. O.; Gabriel, T. A. & Bartine, D. E.
Object Type: Report
System: The UNT Digital Library
Accelerator column models for low-current beams (open access)

Accelerator column models for low-current beams

This paper describes three analytic approaches used to model electrostatic accelerator columns in beam-transport codes for low-current beams and compares the results of each approach with the results obtained by numerically calculating the electric field based on charge distribution on equipotential surfaces. The three analytic approaches described are (1) a cubic energy-gain approximation, (2) a cubic longitudinal electric-field approximation, and (3) the aperture equation. The first two approaches calculate impulse approximations at the apertures, whereas the third is an integration of particle trajectories through the column filed. The conditions under which the solutions tend to break down are discussed. 4 refs., 8 figs.
Date: January 1, 1985
Creator: Rusthoi, D. P.; Allison, P. & Crandall, K. R.
Object Type: Article
System: The UNT Digital Library
Accelerator Technology Program. Status report, October 1983-March 1984 (open access)

Accelerator Technology Program. Status report, October 1983-March 1984

This report covers major projects in the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. The first sections highlight activities related to beam dynamics, inertial fusion, structure development, the racetrack microtron, and the CERN high-energy physics experiment NA-12. Discussed next is the Fusion Materials Irradiation Test Facility, followed by a summary of progress on the Proton Storage Ring and activities of the Theory and Simulation Group. The report concludes with a discussion of the H- accelerator program and a listing of papers published by AT-Division personnel during this reporting period.
Date: January 1, 1985
Creator: Jameson, R.A. (comp.)
Object Type: Report
System: The UNT Digital Library
Accelerator technology working group summary (open access)

Accelerator technology working group summary

A summary is presented of workshop deliberations on basic scaling, the economic viability of laser drive power for HEP accelerators, the availability of electron beam injectors for near-term experiments, and a few very general remarks on technology issues.
Date: January 1, 1985
Creator: Jameson, Robert A.
Object Type: Article
System: The UNT Digital Library
Accelerator vibration issues (open access)

Accelerator vibration issues

Vibrations induced in accelerator structures can cause particle-beam jitter and alignment difficulties. Sources of these vibrations may include pump oscillations, cooling-water turbulence, and vibrations transmitted through the floor to the accelerator structure. Drift tubes (DT) in a drift tube linac (DTL) are components likely to affect beam jitter and alignment because they normally have a heavy magnet structure on the end of a long and relatively small support stem. The natural vibrational frequencies of a drift tube have been compared with theoretical predictions. In principle, by knowing natural frequencies of accelerator components and system vibrational frequncies, an accelerator can be designed that does not have these frequencies coinciding. 2 refs., 2 figs., 2 tabs.
Date: January 1, 1985
Creator: Tennant, R.A.
Object Type: Article
System: The UNT Digital Library
Acceptability testing of radioluminescent lights for VFR-night air taxi operations (open access)

Acceptability testing of radioluminescent lights for VFR-night air taxi operations

Tritium-powered radioluminescent (RL) lights have been under development for remote, austere, and tactical airfield lighting applications. The State of Alaska has requested FAA approval for use of the technology as a safe alternative lighting system to meet the airfield lighting needs of air taxi operations and general aviation in the state. The tests described in this report were performed by PNL for the DOE Defense Byproducts Production and Utilization Program. These tests are a step toward gaining the required approvals.
Date: January 1, 1985
Creator: Jensen, G.A.
Object Type: Report
System: The UNT Digital Library
Accommodation of unprotected accidents by inherent safety design features in metallic and oxide-fueled LMFBRs (open access)

Accommodation of unprotected accidents by inherent safety design features in metallic and oxide-fueled LMFBRs

This paper presents the results of a study of the effectivness of intrinsic design features to mitigate the consequences of unprotected accidents in metallic and oxide-fueled LMFBRs. The accidents analyzed belong to the class generally considered to lead to core disruption; unprotected loss-of-flow (LOF) and transient over-power (TOP). Results of the study demonstrate the potential for design features to meliorate accident consequences, and in some cases to render them benign. Emphasis is placed on the relative performance of metallic and oxide-fueled core designs.
Date: January 1, 1985
Creator: Cahalan, J.E.; Sevy, R.H. & Su, S.F.
Object Type: Article
System: The UNT Digital Library
Accurate determination of the parameters of the 292. 4-eV resonance of /sup 91/Zr and the 301. 1-eV resonance of /sup 96/Zr (open access)

Accurate determination of the parameters of the 292. 4-eV resonance of /sup 91/Zr and the 301. 1-eV resonance of /sup 96/Zr

High-resolution transmission measurements of zirconium metal samples have been carried out at ORELA using the 80-m flight path and an improved /sup 6/Li-glass scintillation neutron detector. Four different thicknesses of the pure zirconium metal and one sample of zircaloy were used in four separate experiments. The transmission data for these samples were measured at room temperature, and one sample was cooled to liquid nitrogen temperature. These data were analyzed using the multilevel R-matrix computer code SAMMY. The resonance parameters obtained for the 292.4-eV resonance of /sup 91/Zr (including both statistical and systematic uncertainties) are: J/sup ..pi../=3/sup +/, E/sub 0/=292.40 +- 0.10 eV, GAMMA/sub n/=665 +- 5 MeV, GAMMA/sub ..gamma../=131 +- 10 MeV, and cc(GAMMA/sub n/, GAMMA/sub ..gamma../)=0.14. The parameters obtained for the 301.1-eV resonance in /sup 96/Zr are: J=1/2, E/sub 0/=301.14 +- 0.10 eV, GAMMA/sub n/=223 +- 7 meV, GAMMA/sub ..gamma../=285 +- 38 MeV, and cc(GAMMA/sub n/, GAMMA/sub ..gamma../)=0.80.
Date: January 1, 1985
Creator: Salah, M.M.; Harvey, J.A.; Hill, N.W.; Hussein, A.Z. & Perey, F.G.
Object Type: Article
System: The UNT Digital Library