The design of future Engineering Test Reactor (ETR) to demonstrate ignition is complicated by the uncertainties in the projected database for ignited plasmas. Application of uncertainty analysis to ETR design utilizing a figure-of-merit defined as the probability of ignition is presented. Performance evaluation from the uncertainty analysis in density-temperature space can locate an optimum operating window for ignition. 11 refs., 5 figs., 3 tabs.

Some examples of nuclear data in which the uncertainty has been underestimated, or at least appears to be underestimated, are reviewed. The subjective aspect of the problem of systematic uncertainties is discussed. Historical aspects of the data uncertainty problem are noted. 64 refs., 6 tabs.

The calculation of kerma factors from known cross sections is not as simple as is often implied. The kerma factors are strongly influenced by the reaction mechanism assumed. An important example of this dependence on the reaction mechanism is the contribution of the /sup 12/C(n,n')3..cap alpha.. reaction to the total kerma in carbon. First, a short review will be given of the ENDF/B-V carbon cross sections which were used in the calculation of carbon kerma factors. Using the reaction channels implied in the ENDF/B-V evaluation, the contribution of various reactions to the total kerma factors in carbon will be given. A detailed analysis of the reaction mechanisms which could contribute to the (n,n')3..cap alpha.. reaction in carbon has been carried out. First their contribution to kerma, independent of cross section, will be calculated and then the initial spectra of alpha particles produced by the various reaction mechanisms will be given. A discussion of possible ways of experimentally distinguishing the reaction mechanisms will be made by comparing their different initial spectra and their variation in kerma with neutron energy. Finally, the event-size spectra for tissue-equivalent proportional counters will be presented, giving only the contributions from the (n,n')3..cap alpha.. reaction and its …

Large-diameter boreholes drilled at the Nevada Test Site for the Department of Energy frequently exhibit an elongation in response to the regional stress field. Single-axis, decentralized logging tools invariably migrate to the long axis of the hole while logging. The long axis is the roughest and is more frequently washed out. The design of these tools therefore ensures that the worst possible side of the borehole is being logged. A new line of geophysical logging tools has been developed at the suggestion of EG and G, Energy Measurements, Inc., to overcome the effect of borehole elongation. A pair of orienting arms set at 90/sup 0/ to the measurement axis effectively turn the tool so that measurements are always recorded on the smoother, short side of the borehole. 3 refs., 5 figs.

The Mirror Advanced Reactor Study (MARS) is a conceptual design study for a commercial fusion power reactor. One of the major goals of MARS is to develop design guidance so that fusion reactors can meet reasonable expectations for environmental health and safety. One of the first steps in the assessment of health and safety requirements was to examine what the guidelines might be for health and safety in disposal of radioactive wastes from fusion reactors. Then, using these quidelines as criteria, the impact of materials selection upon generation of radioactive wastes through neutron activation of structural materials was investigated. A conclusion of this work is that fusion power systems may need substantial engineering effort in new materials development and selection to meet the probable publicly acceptable levels of radioactivity for waste disposal in the future.

We have derived absolute dipole strength-function information for /sup 176/Lu from an average resonance capture study of /sup 175/Lu with 2-keV neutrons and from neutron capture cross-section measurements with neutrons from 30 keV to about 1 MeV. We found that we needed to increase our previous estimate of the relative M1/E1 strengths near 5 MeV by a factor of 3 and to revise downward the absolute magnitude of our E1 strength function. We accomplished the latter, while still maintaining continuity with the photonuclear data, by adjusting the one free parameter in our line shape. The present E1 and M1 strengths now seem correct both near the neutron separation energy and also around 1 MeV.

The coherent interaction between an optical wave and an electron beam in a free electron laser (FEL) is shown to be capable of optically guiding the light. The effect is analyzed using a two-dimensional approximation for the FEL equations, and using the properties of optical fibers. Results of two-dimensional (cylindrically symmetric) numerical simulations are presented, and found to agree reasonably well with the analytically derived criterion for guiding. Under proper conditions, the effect can be large and has important applications to short wavelength FEL's and to directing intense light.

Cobalt activation calculations will be reviewed, and similar comparisons of sulfur activation interior to electrical insulators on power transmission lines will be discussed. The relationship between neutron tissue kermas one to two kilometers from hypocenter and the particular activations of cobalt and sulfur are reviewed. At present, measured and calculated quantities agree within associated uncertainties, which are substantial. Additional work to shrink these uncertainties will be discussed. Particular cobalt activation topics will include: the sensitivity to thermal neutrons outside the pillar; calculated values using actual Nagasaki concrete composition; and calculational advances to improve modelling of the actual configuration. Particular sulfur activation topics will include: absolute comparisons of measured and calculated ratios of dpm/gm of /sup 32/P at all measured ranges, based on approximate experimental values for insulator attentuation and source radiations; the relationship between sulfur activation within a kilometer of hypocenter and kermas at two kilometers; and calculational advances to improve modelling of the actual configuration.

We discuss the formal basis for the theoretical treatment of nuclear multifragmentation within a microcanonical framework. The important role played by highly excited nuclear states and the interfragment forces is illustrated. The requirement of detailed balance is especially discussed and illustrated for the fission-fusion Metropolis moves in configuration space. 13 refs., 2 figs.

For an energy-efficient accelerator system to be used for a free-electron laser, the stability of an energy-recovery system utilizing a bridge coupler placed between the accelerator and the decelerator is studied numerically. Energy is recovered by recirculating the accelerated electron beam through the decelerator; the recovered energy is then transported through the bridge coupler to the accelerator. The calculation shows that a large transient voltage oscillation is induced in the system. This transient oscillation can be reduced significantly by slowly applying both the electron-beam current and the klystron power at the beginning. Two types of instabilities are predicted according to the scraping of the electron beam between the accelerator and the decelerator. When the energy spectrum of the electron beam is scraped at the high end, the system induces an oscillation. However, when the low-energy end is scraped, the electron recirculation may stop unless the klystron power is boosted by a feedback system.

This brief discussion of replicons of higher plants offers a glimpse into the properties of chromosomal DNA replication. It gives evidence that the S phase of unrelated plant species is comprised of temporally ordered replicon families that increase in number with genome size. This orderly process, which assures a normal inheritance of genetic material to recipient daughter cells, is maintained at the level of replicon clusters by two mutually exclusive mechanisms, one involving the rate at which single replicons replicate their allotment of DNA, and another by means of the tempo-pause. The same two mechanisms are used by cells to alter the pattern of chromosomal DNA replication just prior to and during normal development. Both mechanisms are genetically determined and produce genetic effects when disturbed of disrupted by additional non-conforming DNAs. Further insight into how these two mechanisms operate requires more molecular information about the nature of replicons and the factors that govern when a replicon family replicates. Plant material is a rich and ideal source for this information just awaiting exploitation. 63 refs.

One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa < 1) increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency.

The lasertron is more efficient, lighter, and smaller than a klystron, especially at outputs below 2 GHz. Higher peak output powers are possible with the lasertron, and a separate modulator is not required. These advantages are useful for rf accelerators and linear colliders. The electron dynamics are simulated to estimate the device performance limits and to design an experimental lasertron. The relativistic electron dynamics are followed from the photocathode through the acceleration region and through the output region. The total fields are the sum of the space-charge, external magnetic, and acceleration or output-cavity fields. Wake fields are ignored, and the steady-state output fields are found. Lasertron performance as a function of acceleration field, charge per pulse nd frequency is calculated, showing its avantages and limitations. A preliminary design for the first Orsay lasertron experiment is presented.

A beam buncher has been designed, fabricated, and installed on the accelerator test stand (ATS) to match the 2-MeV output beam of a 425-MHz H/sup -/ radio-frequency quadrupole (RFQ) into a 425-MHz drift-tube linac (DTL). The buncher configuration provides integral-matching permanent-magnet quadrupoles (PMQ) at the exit of the RFQ and one ..beta..lambda across the buncher accelerating gap; a third PMQ is the first DTL half-cell magnet. Located between the second and third PMQs is a 50-..cap omega.., capacitively coupled, beam-sensing pickup loop. Cooling channels are provided in each of the brazed OFHC copper wall sections. Vacuum pumping of the buncher is provided by a cryogenic refrigerator vacuum pump through an array of small-diameter holes in the buncher cavity wall. Mechanical features of the buncher, the brazing and electron-beam welding of the solid-copper buncher structure, and the beam pickup loop are described in this paper. The buncher has been tuned, installed, and operated at full power on the ATS.

Power from inertial confinement fusion holds much promise for society. This paper points out many of the benefits relative to combustion of hydrocarbon fuels and fission power. Potential problems are also identified and put in perspective. The progress toward achieving inertial fusion power is described and results of recent work at the Lawrence Livermore National Laboratory are presented. Key phenomenological uncertainties are described and experimental goals for the Nova laser system are given. Several ICF reactor designs are discussed.

A description of experiment E665 at Fermilab is given. Data were taken at muon energies of 500 and 100 GeV and with targets of H/sub 2/, D/sub 2/, and Xe. Initial analysis of the first run's data has commenced. Physics topics addressed by the experiment are given. 1 ref., 1 fig., 1 tab.

We report laser experiments on a 248 nm KrF laser with a 30x40x120 cm gain volume and an injection locked unstable resonator cavity. The volume is pumped by six 450 kV, 90 kA electron beam generators using water pulse forming lines.

A specific problem developed during the design of an on-line sampling system for the Sodium Loop Safety Facility fast breeder reactor experiments. Rapid fluctuations in the sodium temperature, caused by reactor operation and shutdown, exposed the system components to conditions that could result in fatigue failure. A component test loop was designed and built at the Idaho National Engineering Laboratory to allow experimental qualification of component integrity. This paper outlines test system requirements, describes the design and special features, presents test procedures ad relates significant operating experience.

The small-angle source (SAS) and 4X source are Penning surface-plasma sources (SPS) that produce high-brightness H/sup -/ ion beams for accelerator applications. However, electrode cooling considerations have limited the duty factor for pulsed operation to 1 to 3% and the maximum cw H/sup -/ beam to 2 to 4 mA. The addition of some active cooling to the 4X source has allowed pulsed operation at 6% duty factor for arc parameters sufficient to produce approx. 100 mA of H/sup -/ beam. More vigorous cooling, now being added, should allow production of cw H/sup -/ beams up to 20 to 40 mA. The cooled electrodes were designed using the predictions of TOPAZ2D, a 2-D transient, conductive heat-transfer code. The latest results, along with the possibility of producing even larger cw II/sup -/ beam currents, will be discussed.

A design concept is presented for an advanced hadron facility consisting of a combined kaon factory and second generation spallation source. Our proposed facility consists of a 1.2 GeV superconducting H/sup -/ linac to bring the LAMPF energy up to 2 GeV, a multi-ring 2 GeV compressor, a shared cold-neutron and stopped-pion neutrino source, a 60 GeV 25 ..mu..Amp 6 Hz proton synchrotron, and kaon and proton experimental areas. We discuss the considerations which led to this design concept. We summarize recent results of r and d work on components for rapid-cycling synchrotrons. Finally, we mention briefly a pion linac, which may be a good way to gain experience with superconducting cavities if advanced hadron facility funding is delayed.

This report is the proceedings of the Seminar on geothermal development opportunities in developing countries, sponsored by the Geothermal Division of the US Department of Energy and presented by the National Geothermal Association. The overall objectives of the seminar are: (1) Provide sufficient information to the attendees to encourage their interest in undertaking more geothermal projects within selected developing countries, and (2) Demonstrate the technological leadership of US technology and the depth of US industry experience and capabilities to best perform on these projects.

This paper describes the improved mesh generator of the POISSON Group Codes. These improvements enable one to have full control over the way the mesh is generated and in particular the way the mesh density is distributed throughout this model. A higher mesh density in certain regions coupled with a successively lower mesh density in others keeps the accuracy of the field computation high and the requirements on the computer time and computer memory low. The mesh is generated with the help of codes AUTOMESH and LATTICE; both have gone through a major upgrade. Modifications have also been made in the POISSON part of these codes. We shall present an example of a superconducting dipole magnet to explain how to use this code. The results of field computations are found to be reliable within a few parts in a hundred thousand even in such complex geometries.

The usual conditions for achromaticity of a dispersive system are shown to be inadequate when space-charge effects are included. Using a matrix formulation describing linear space-charge forces, we give generalized criteria necessary for a system to be achromatic. Additionally, these conditions are necessary for conservation of transverse emittances. An example of such a system is given.

The changes in the sensitivity (S) and the equivalent X-ray limit (P/sub x/) of several Bayard-Alpert gauges (BAGs) were studied when the size of the collectors was reduced from 125 ..mu.. to 50 ..mu.. and when different mounting envelopes were used. Based on this study, 400 custom BAGs with 50 ..mu.. collector were purchased from a vendor. The S and the P/sub x/ of these thin-collector BAGs were also measured.