Results are presented of comparative timing tests made by running a typical FORTRAN physics simulation code on the following machines: DEC PDP-10 with KI processor; DEC PDP-10, KI processor, and FPS AP-190L; CDC 7600; and CRAY-1. Factors such as DMA overhead, code size for the AP-190L, and the relative utilization of floating point functional units for the different machines are discussed. 1 table.

Two passive magnetic-shielding-design approaches for static external fields are reviewed. The first approach uses the shielding solutions for spheres and cylinders while the second approach requires solving Maxwell's equations. Experimental data taken at LLNL are compared with the results from these shieldings-design methods, and improvements are recommended for the second method. Design considerations are discussed here along with the importance of material gaps in the shield.

Recent measurements of the cosmic background radiation (CBR) show an enhanced flux in the submillimeter regime, compared to the spectrum of a 2.7 K blackbody. Thermal Comptonization of the relic radiation by a hot nonrelativistic plasma has long been known to produce distortions in the CBR spectrum, similar to what has now been observed. Heating of the primeval plasma to temperatures T {approximately} 10{sup 6} {minus} 10{sup 8} K could result from the injection of subcosmic ray protons at epoch z {approximately} 10--100. The intensity of the subcosmic ray flux that provide conditions needed to explain the submillimeter excess by thermal Comptonization also leads to the production of cosmologically significant amounts of deuterium in collisions between subcosmic ray protons and primordial protons and {alpha}-particles. However, the amount of lithium produced through {alpha}-{alpha} reactions is in conflict with the observed Li abundance. If lithium is depleted, for example, by processing through Population II stars, arguments for the baryon content of the universe based on primordial deuterium and He abundances are weakened. 12 refs., 1 fig., 1 tab.

Diffusion welding is shown to be a feasible method for joining composites of niobium-titanium superconductor alloy filaments in a pure copper matrix. Good results were repeatedly obtained using 15/sup 0/ scarf joints welded with externally heated tooling and simple uniaxial compression loading in a conventional hydraulic press. Weld cycles of less than one hour total elapsed time were readily attainable. Through proper closed-die design, it was possible to increase welding pressure sufficiently to use relatively low temperatures to coincide with the optimum aging heat treatment of the superconductor alloy. This temperature limitation is important to retain optimal superconductor properties. Confirming measurements of critical current density of welded joints at 4.2/sup 0/K are in progress. In the welded joints made under optimum conditions, there is bonding of all constituents, including superconductor filaments. Weld tooling which effectively contains the relatively fluid matrix, and resists deformation during repeated weld cycles, is essential to the successful application of the diffusion welding process to these composites.

The ability of a country to follow sustainable development paths is determined to a large extent by the capacity or capabilities of its people and its institutions. Specifically, capacity-building in the UNCED terminology encompasses the country's human, scientific, technological, organizational, institutional, and resource capabilities. A fundamental goal of capacity-building is to enhance the ability to pose, evaluate and address crucial questions related to policy choices and methods of implementation among development options. As a result the United Nations Conference on Environment and Development (UNCED) Agenda 21 planning process has identified the need for better methods by which information can be transferred between industrialized nations and developing nations. The reasons for better methods of information transfer include facilitating decisions related to sustainable development and building the capacity of developing nations to better plan their future in both an economical and environmentally sound manner. This paper is a discussion on mechanisms for providing information and technologies available for presenting the information to a variety of cultures and levels of technical literacy. Consideration is given to access to information technology as well as to the cost to the user. One concept discussed includes an Engineering Partnership'' which brings together the talents and resources …

Technology requirements for mirror hybrid reactors are discussed. The required 120-keV neutral beams can use positive ions. The magnetic fields are 8 T or under and can use NbTi superconductors. The value of Q (where Q is the ratio of fusion power to injection power) should be in the range of 1 to 2 for economic reasons relating to the cost of recirculating power. The wall loading of 14-MeV neutrons should be in the range of 1 to 2 MW/m/sup 2/ for economic reasons. Five-times higher wall loading will likely be needed if fusion reactors are to be economical. The magnetic mirror experiments 2XIIB, TMX, and MFTF are described.

I am pleased to speak at the Fortieth Gordon Conference on Nuclear Chemistry. I served as Chairman of the first Gordon Conference on Nuclear Chemistry held June 23--27, 1952, at New Hampton, New Hampshire. In my remarks, during which I shall quote from my journal, I shall describe some of the background leading up to the first Gordon Conference on Nuclear Chemistry and my attendance at the first seven Gordon Conferences during the period 1952 through 1958. I shall also quote my description of my appearance as the featured speaker at the Silver Anniversary of the Gordon Research Conferences on December 27, 1956 held at the Commodore Hotel in New York City. I shall begin with reference to my participation in the predecessor to the Gordon Conferences, the Gibson Island Research Conferences 45 years ago, on Thursday, June 20, 1946, as a speaker. This was 15 years after the start of these conferences in 1931. Neil Gordon played a leading role in these conferences, which were named (in 1948) in his honor -- the Gordon Research Conferences -- soon after they were moved to Colby Junior College, New London, New Hampshire in 1947. W. George Parks became Director in 1947, …

This paper is a progress report on work at the Lawrence Livermore National Laboratory (LLNL) to perform a limited seismic reassessment of the Robert E. Ginna Nuclear Power Plant. The reassessment is being done for the Nuclear Regulatory Commission (NRC) as part of the Systematic Evaluation Program. The reassessment focuses generally on the reactor coolant pressure boundary and on those systems and components necessary to shut down the reactor safely and to maintain it in a safe shutdown condition following a postulated earthquake characterized by a peak horizontal ground acceleration of 0.2 g. Methods and modeling procedures used to analyze a complex of interconnected buildings are highlighted.

A complex, and apparently stochastic, character frequently can be seen to occur in the solutions to simple Hamiltonian problems. Such behavior is of interest, and potentially of importance, to designers of particle accelerators--as well as to workers in other fields of physics and related disciplines. Even a slow development of disorder in the motion of particles in a circular accelerator or storage ring could be troublesome, because a practical design requires the beam particles to remain confined in an orderly manner within a narrow beam tube for literally tens of billions of revolutions. The material presented is primarily the result of computer calculations made to investigate the occurrence of ''stochasticity,'' and is organized in a manner similar to that adopted for presentation at a 1974 accelerator conference.

A laboratory-scale experimental device having an outside diameter of 1.2 m has been designed to test the idea of electrostatic end plugging of an open-ended magnetic-field configuration. The configuration is a toroidal quadrupole having four very thin (less than 1-mm-thick) line cusps produced by four circular copper coils. Iron is used to concentrate the magnetic flux density to 2.0 T; without the use of iron, the power consumption, which is about 1 MW, would be about 25 times higher. The use of iron also produces a precisely known magnetic field and allows good access for diagnostics and pumping. Iron is also used for both the flux return path and the vacuum chamber. A hollow anode with an adjustable (nominally 1-mm-wide) gap is biased from 10 to 20 kV. Plasma densities of about 10/sup 13/ cm/sup -3/ and temperatures of about 1 keV might be produced by an electron beam and by electron cyclotron resonance heating. Higher-order multipoles (hexapoles and octopoles) also are described.

Two novel techniques which produce a uniform frozen layer of deuterium-tritium on the inside surface of a glass microsphere are presented.

Article on electronic and transport properties of artificial gold chains.

Article on phase equilibria in high energy density PVDF-based polymers.

Article on dynamic conductance of carbon nanotubes.

Article on a theoretical study of the ultimate strength of carbon nanotubes.

We have developed techniques for measuring the power and frequency of the Electron Laser Facility (ELF) II free-electron laser (FEL) used for plasma heating experiments on the Microwave Tokamak Experiment (MTX). We also have designed a multichannel, 140-GHz receiver capable of measuring FEL power levels from 10 mW to 0.1 {mu}W within an accuracy of {plus minus}1 dB with a 50-dB dynamic range and a 2-ns response time. By using calibrated attenuators, we can measure power levels from 10 GW to 0.1 {mu}W. We sample the microwave output of the FEL in a microwave load tank by using WR-8 or WR-28 stub waveguide antennas. Microwave turning mirrors are used to guide the microwave beam down an evacuated beam tube to the MTX. Stub, WR-8, fundamental-mode, waveguide antennas are used for beam detection on the microwave turning mirrors. Orthogonal, WR-8, stub waveguides are machined into the surfaces of the mirrors and used as directional couplers to measure forward and reflected power from the FEL. The microwave power is then transported to the microwave receiver via a low-loss, over-moded, WR-28 waveguide. A movable modes probe in the microwave load tank is used to scan across the microwave beam to determine the modes …

A rocket powered by fusion microexplosions is well suited for quick interplanetary travel. Fusion pellets are sequentially injected into a magnetic thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding magnetic field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and magnetic thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm/sup -1/, which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs.

This is a continuation of previous studies aimed at predicting spectral signatures of discrete cosmic-ray sources. In this paper, a formalism is developed for calculating gamma-ray spectra observed at Earth from the decay of neutral pions formed in collisions of cosmic-ray protons and ions with galactic gas and dust. The cosmic rays are assumed to be emitted by discrete sources, and their intensities and spectra are described by solutions to a diffusion equation. Calculations of spectral signatures expected from these hypothetical point sources of cosmic rays are presented. In particular, a steady source of cosmic rays could show a harder gamma-ray spectrum than the spectrum of the diffuse galactic background, whereas an impulsive source of cosmic rays could show a much softer spectrum. Observations of the angular variations of gamma-ray intensities and spectra near point sources will provide information on cosmic-ray propagation in other parts of our galaxy, as well as on the nature of the discrete sources themselves. Capabilities of the Egret telescope in mapping spectra from cosmic-ray point sources are briefly discussed. 14 refs., 2 figs.

Information is presented concerning transients in research reactors and nuclear power plants.

The Tandem Mirror Experiment (TMX) system, part of the Lawrence Livermore Laboratory magnetic mirror program incorporates in its design various types of coils or magnets. This paper describes the physical construction of each coil within the system as well as the structural design required for their support and installation.

Transuranium elements have been introduced to the environment by a variety of ways including fallout from weapons testing, leakage from nuclear power reactors, waste effluent from nuclear fuel processing and leakage of radioactive waste from ocean dump sites. Several methods of curium detection and analysis in samples from marine ecosystems are contrasted and discussed in this paper.

This paper presents the design and construction, as well as the initial operation, of the Microwave Transmission System. The system consists of containment vessels, mirror boxes, mirrors, an alignment system, two turbo-molecular pump vacuum stations, and microwave source. Fifty-ns-length pulses of 6-MeV electrons pass through a free electron laser (FEL) wiggler. A 300 W extended interaction oscillator (EIO) of 140 GHz frequency supplies the seed signal for amplification in the wiggler. The electron beam is dumped and the microwave beam is transmitted quasi-optically 90 ft by six aluminum mirrors through an evacuated tube. Three of the mirrors are elliptical paraboloids and the others are flat. A seventh mirror is rotated into the microwave beam to divert it into a load tank. The transport vacuum vessel is 20-in.-diameter stainless steel tube with bellows and mirror boxes at each mirror. Two vacuum systems at each end of the transport tube allow a base pressure of 10{sup {minus}7} Torr to be attained by 7000 L/s of turbo-molecular pumping. Also at each mirror, at the MTX vessel, and at the two ends of the wiggler waveguide are HeNe laser detectors used for vacuum alignment. Descriptions of the major components, their requirements and system requirements …

A method is developed to compress a heavy-ion beam longitudinally in such a way that the compressed pulse has a constant line-charge density profile and uniform longitudinal momentum. These conditions may be important from the standpoint of final focusing. By realizing the similarity of the equations that describe the 1-D charged-particle motion to the equations that describe 1-D ideal gas flow, the evolution of lambda and the velocity tilt can be calculated using the method of characteristics developed for unsteady supersonic gasdynamics. Particle simulations confirm the theory. Various schemes for pulse shaping have been investigated.

Article on switchgrass (Panicum virgatum) possessing a divergent family of cinnamoyl CoA reductases with distinct biochemical properties.