Analysis of the sensitivity of previous negative searches for magnetic monopoles shows that they constitute prior evidence against the monopole interpretation of the event reported as ''evidence for detection of a moving magnetic monopole''. The strength of the evidence varies with the unknown mass of the monopole. For M less than or equal to 10/sup 5/ GeV, odds are greater than 10/sup 6/ : 1 against. For larger masses, the limits depend strongly on assumptions about the range of monopoles and the threshold for detection of monopole tracks in obsidian. In no case are the odds, less than 8 : 1 and they may be no less than 8000 : 1 against. Since the reported event may also be due to an electrically charged heavy particle, it is probably not due to a monopole.

A fast-neutron pinhole camera with high detection efficiency and nanosecond time-resolution has been developed and applied to the investigation of the spatial and temporal distributions of DD- and DT-neutrons produced by thermonuclear plasmas. The pinhole consists of a specially designed 1.15 m long copper collimator with an effective aperture of 1 mm diameter. Several different types of spatial resolution detectors have been used at the image plane: (1) a multi-element, scintillation-photomultiplier system used for time-resolved measurements consisting of sixty-one individual detectors, (2) a scintillation-fiber-chamber coupled to a gated image-intensifier tube used for direct photographing of the neutron image, and (3) a propane bubble chamber used for time-integrated recording with a capability to distinguish DD- from DT-neutrons. Pulsed neutron sources with typical dimensions of 1 cm emitting of the order of 10/sup 12/ neutrons over a time period of 10-100 nsec have been investigated. A spatial resolution of 1 mm and a time resolution of approximately 10 nsec was achieved in the investigations of dense plasma compression phenomena.

High energy neutron sputtering yields have been determined for Nb, Au and Co. Two experiments have been conducted. In the first, graphite catcher foils were used, and in the second, polished Si wafers. From data collected in the first experiment the neutron sputtering yields of Nb, Au and Co were determined to be in the range of 10/sup -5/ to 10/sup -4/ particles per incident neutron. Examination of the collector foils from the second experiment did not show any evidence of large particle ejection from the Nb targets.

This paper reviews methods of environmental sampling for radionuclides around operational and preoperational nuclear power plants. We examine in detail the implications of the established radiation standards and their effect on sampling procedures. Transport mechanisms of radionuclides in liquid effluent, and the deposition of airborne radionuclides onto soil and vegetation are discussed. We evaluate water- and soil-sampling procedures. The Lawrence Livermore Laboratory program of terrestrial gamma-ray surveys at preoperational nuclear power plants is described.

Shiva consists of 2,200 flashlamp units. The reliability of such units is studied. The probability that none of the units will fail if they are to undergo a certain number of shots (say 50, 100 or 200) provided that all these units have been tested for a given number of shots is estimated. The data used to develop the method are given. Suitable models for the failure rate of an individual unit are considered, and the parameters for these models are computed. The best model is selected and reliability estimates are made using the limited data available. The steps that were taken to evaluate this estimate are summarized.

Discussed are energy depositions in the first wall of various proposed laser-fusion reactors and the effect of pulse time on the stress and temperature in the first wall. Simple models can be used to estimate the temperature and stress rise from x-rays and neutrons. More complex analysis is needed to estimate the response of the first wall to reflected laser light and the pellet debris.

In the structural design of LMFBR components for elevated temperature service it is necessary to take account of the time-dependent, creep behavior of materials. The accommodation of creep to assure design reliability has required (1) development of new design limits and criteria, (2) development of more detailed representations of material behavior, and (3) application of the most advanced analysis techniques. These developments are summarized and examples are given to illustrate the current state of technology in elevated temperature design.

A review is given of the uses of particle accelerators in health physics, the text being a short course given at the Health Physics Society Ninth Midyear Topical Symposium in February, 1976. Topics discussed include: (1) the radiation environment of high energy accelerators; (2) dosimetry at research accelerators; (3) shielding; (4) induced activity; (5) environmental impact of high energy accelerators; (6) population dose equivalent calculation; and (7) the application of the ''as low as practicable concept'' at accelerators. (PMA)

The Lawrence Berkeley Laboratory (LBL) is now constructing a test facility for the development of neutral beam (NB) sources which will operate up to a level of 150 kV, 20A, 0.5 sec with a 1 percent duty cycle (1). Such sources will provide neutral deuterium beams for injection into large-scale experimental fusion devices. These sources require an accel power supply capable of wide-range variation, voltage regulation of +-1 percent, risetime less than or equal to 20 ..mu..sec, turnoff (crowbar) time of less than or equal to 10 ..mu..sec, repetitive crowbarring and restarting during a 0.5 sec pulse, and low rate of current increase during a short circuit. A shunt regulator system is described which uses existing components and satisfies these requirements with simplicity and relatively low cost.

A simulation of a theta-pinch fusion power plant has been completed to the point where economic feasibility can be examined. A PL/I cost subprogram is presented for interfacing with the computer code TPFPP. This code is then used to obtain a first approximation of the costs for the reactor. Independent geometrical and plant design parameters are varied over a wide range, with simultaneous variation of magnetic field, minor first wall radius, and plasma maximum compression. The study indicates that the plant energy balance must be favorable, availability must be high, and major component costs must be low to achieve economical results. Although costing uncertainties remain, it is clear that development of easy and rapid replacement methods for reactor components is essential and that new staging concepts to reduce the implosion energy requirement must be pursued.

Electrical noise interference in low-level (approximately 50 ..mu..V), wide band (approximately 15 MHz) flux monitoring systems applied to nuclear reactor control causes safety and reliability problems. Others have shown that one predominant source of noise interference is conduction of currents in instrument cable shields and building conduits. Since these currents produce noise that is similar to signals produced by nuclear detectors, such noise interference reduces the ability of a reactor instrumentation system to determine the condition of a reactor. Model equations of ground noise interference were derived for a system model consisting of a sensor, coaxial cable, and an amplifier. These equations describe the effect of ground impedance, sensor impedance, transfer impedance, and connector resistance on both low-frequency (less than 100 kHz) and high-frequency (greater than 100 kHz) ground noise interference. Other model equations were derived for a system with a coaxial balun (a flexible coaxial cable wound around a ferrite core) added between the sensor and the sensor amplifier input. Analysis of the model equations reveals the effects of ground noise currents on instrumentation systems and the conditions for minimizing ground interference.

Primary recoil distributions and specific damage energies have been computed for high energy deuteron-breakup neutrons in Cu, Nb, and Au. The calculations are based on theoretical neutron cross sections, and consider in particular a d-Be spectrum broadly peaked at 15 MeV with some neutrons above 30 MeV. The theoretical results are similar to corresponding calculations for monoenergetic 15-MeV neutrons and are in good agreement with range measurements of (n,2n) recoils generated by high energy d-Be neutrons in Nb and Au. The calculations are also consistent with recent d-Be neutron sputtering experiments in Nb and Au and demonstrate the usefulness of deuteron-breakup neutron sources for simulating fusion neutron effects. (auth)

The neutral-beam injection systems for the next generation of U. S. fusion experiments (TFTR, MX, Doublet III) have requirements that considerably exceed the present state of development. TFTR, for example, desires 20 MW of 120-keV deuterium atoms in pulses of 0.5-sec duration. The neutral-beam systems needed to meet these demands will be large and complex and will require much development effort. In order to develop components for these new systems, a new, large test facility was constructed. The vacuum system, which has a volume in excess of 170,000 liters, will handle the pulsed gas loads by volume expansion; the gas will be pumped out in the one-minute intervals between pulses. The power-supply philosophy and specification are discussed in an accompanying paper. A mini-computer system will be used to monitor and control the power supplies and to diagnose the beam. Of the beam-line components, a plasma source and 120-kV accelerator structure which are under construction are discussed. A new long-pulse version of our 15-cm-diam high-current plasma source has been developed. Significant improvements have been made by re-orienting the filaments, so that they produce closed magnetic field lines near the wall, and by changing the shape and position of the anode. This …

Experimental values obtained for x-ray mass attenuation coefficients between the M/sub I/ and M/sub V/ absorption edges of rhenium are presented below. Also presented is a brief discussion of the experimental procedure.

Visible, ultraviolet, and infrared optical emission results from low- energy (20 eV-10 keV) particle-surface collisions. Several distinct kinds of collision induced optical radiation are discussed which provide fundamental information on particle-solid collision processes. Line radiation arises from excited states of sputtered surface constituents and backscattered beam particles. This radiation uniquely identifies the quantum state of sputtered or reflected particles, provides a method for identifying neutral atoms sputtered from the surface, and serves as the basis for a sensitive surface analysis technique. Broadband radiation from the bulk of the solid is attributed to the transfer of projectile energy to the electrons in the solid. Continuum emission observed well in front of transition metal targets is believed to arise from excited atom clusters (diatomic, triatomic, etc.) ejected from the solid in the sputtering process. Application of sputtered atom optical radiation for surface and depth profile analysis is demonstrated for the case of submonolayer quantities of chromium on silicon and aluminum implanted in SiO$sub 2$.

Reflection of 50 eV to 10 keV H atoms from polycrystalline Cu, Nb and Au targets has been calculated using the binary collision cascade program MARLOWE. The fractions of particles and energy reflected (backscattered) increase with increasing atomic number of the target and decrease with increasing incident energy. The results indicate that the effects of polycrystallinity are modest, reducing the amorphous reflection coefficients by about 25 percent. The calculations agree quite well with the experimental data for Cu and Au, but are about a factor of two larger than is observed for Nb.

Arrival rates of D$sup 0$, T$sup 0$, D$sup +$, T$sup +$, He$sup ++$, neutrons, and photons are given for FERF (Fusion Engineering Research Facility, a mirror confinement reactor dedicated to materials research and to component testing), a hybrid fusion-fission reactor designed primarily to produce fissile fuel, and a D-T power reactor design. For comparison a next-generation confinement-mirror experiment called MX is included. The surfaces of interest are the first wall, the end wall, the direct converter and the injector. (auth)

The unique constraints imposed on the interactions of energetic heavy ions as a result of the channeling effect are utilized to investigate the phenomenon of radiative electron capture (REC) for 17 to 40 MeV oxygen ions. Measured cross-sections and widths of the REC radiation are compared with calculations made specifically for the channeling situation.

A personnel monitoring program must include a well integrated combination of dose determination methods, and should not depend on a single dosimetry system. Many of the necessary techniques have become well developed and dependable, such as the personnel gamma dosimeters in use today. However, other monitoring methods are still not adequate. The two most important personnel monitoring problems remaining are development of personnel neutron dosimeter and in-vivo measurement of plutonium at sublung burden levels. Although there are a few techniques under development to attack these problems, satisfactory long-term solutions will require much more work. As the developments in nuclear power and medicine continue, the need for solutions to these problems will intensify. (auth)

Measurements of gases released from 302 stainless steel and gold surfaces before and after discharge cleaning were made in ultrahigh vacuum using x-rays with an energy distribution typical of a tungsten bremsstrahlung spectrum. Similar measurements were also made for Al$sub 2$O$sub 3$ surfaces which had not been discharge cleaned. For the non-discharge-cleaned surfaces of stainless steel, Al$sub 2$O$sub 3$, and gold the predominant gas species observed mass spectrometrically was CO$sub 2$. For some stainless steel and Al$sub 2$O$sub 3$ surfaces CO and O$sub 2$ were also readily observed. Mean quantum yields for CO, O$sub 2$ and CO$sub 2$ release from such stainless steel surfaces, for example, ranged from less than 6 x 10$sup -5$ to 9 x 10$sup -4$ molecules per photons in the bremsstrahlung spectrum characteristic for 50 keV electron energy. After discharge cleaning a decrease in the mean quantum yields was observed for the stainless steel and gold surfaces. (auth)

Displacement damage by 15 MeV (d-Be source) and fission neutrons at 30$sup 0$C in high purity niobium single crystals has been studied by transmission electron microscopy. The fluence of the 15 MeV neutrons was 1.5-- 2.0 x 10$sup 17$ n/cm$sup 2$ and the fluence of the fission neutrons (5 x 10$sup 17$ n/cm$sup 2$) was chosen so that samples from both types of irradiations had approximately the same damage energy. In both 15 MeV and fission neutron irradiated specimens, the loops were observed to be about $sup 2$/$sub 3$ interstitial and $sup 1$/$sub 3$ vacancy type. The analysis of Burgers vectors of the dislocation loops showed that more than $sup 2$/$sub 3$ of the loops were perfect a/2(111) and that the rest were a/2(110) faulted. It is concluded that at equal damage energies, the detailed nature of the damage is the same for 15 MeV and fission neutron irradiated niobium. (auth)

A quasi-linear theory of energy flux limitation by ion acoustic turbulence is presented. This distribution function is modelled by a Maxwellian plus an additional piece which carries a heat flux Q. By taking the fourth moment of the Vlasov equation one finds the anomalous thermal conductivity K approximately 3 v/sub e/ lambda/sub De/ (e phi/T/sub e/)$sup -2$. Other moments treated self-consistently include anomalous ion heating, electron cooling, current generation and enhanced inverse bremsstrahlung due to the nonthermal ion fluctuations. (auth)

Photocopy of an essay on how the Dellana family came to reside in Rollingwood, Texas. Castro talks about Condado Dellana's immigration from Italy to the United States and how he eventually moved to Texas to help build the capitol building in Austin. Years later, Condado discovered a cave in Rollingwood that produced extremely good fertilizer due to the guano from the bats that lived in the cave. He eventually bought the property that the cave was on and started selling the fertilizer to nurseries around the state.