A model for printed circuit boards which can be used to predict the probability that a router will successfully make a connection is presented. The model reflects certain characteristics of the circuit board that is being routed and the model incrementally changes as the board is routed. Routing procedures typically have certain parameters which influence selection of the set of paths that are explored, and determine the order of exploration. These parameters obviously influence the probability that a particular connection can be made. These parameters may also be used to formulate a model of the behavior of a particular routing procedure.

The plasma focus is a remarkable natural phenomena that achieves significant space-time compression of both particle and field energy. Depending on the mode of operation, about 20 percent of the bank energy can be concentrated into the kinetic energy of a thin, dense, cylindrically convergent gas shell, or into a small-diameter, high-$nu$/$gamma$ relativistic electron burst and oppositely directed ion burst. The kinetic energy of the fast ions and electrons can exceed the applied voltage by a factor of greater than 100. The different modes of energy concentration by the plasma focus are presented and discussed both in terms of their role in the direct yield of the focus and for the case of a plasma focus supplemented by various fusionable targets. (auth)

Thermoluminescence dosimetry is the principal means of measuring ambient $gamma$ radiation at the Lawrence Livermore Laboratory. These dosimeters are used at 12 perimeter locations and 41 locations in the off-site vicinity of the Laboratory, and are exchanged quarterly. Control dosimeters are stored in a 75- mm-thick lead shield located out-of-doors to duplicate temperature cycling of field dosimeters. Effect of dosimeter response to radiation in the shield is determined each quarter. Calibration irradiations are made midway through the exposure cycle to compensate for signal fading. Terrestrial exposure rates calculated from the activities of naturally occurring uranium, thorium, and potassium in Livermore Valley soils vary from 3 to 7 $mu$R/hr. Local inferred exposure rates from cosmic radiation are approximately 4 $mu$R/hr. TLD measurements are in good agreement with these data. Off-site and site perimeter data are compared, and differences related to Laboratory operations are discussed. (auth)

A radiological survey of Bikini and Eneu Islands of the Bikini Atoll was conducted during June 1975 to assess the potential radiation doses that may be received by the returning Bikinians. Bikini Atoll was one of the U.S. nuclear weapons testing sites in the Pacific. An integral part of the survey included measurements of the gamma-ray exposure rates at 1 m above the ground with portable NaI instruments at nearly 2700 locations on the two islands. For comparison purposes, similar measurements were made with a pressurized ion chamber at approximately 200 locations, and with LiF and CaF$sub 2$:Dy thermoluminescent dosimeters (TLDs) at 80 locations. The results indicate that the NaI scintillators overresponded because of their nonlinear energy characteristics. The responses of the LiF dosimeters and the pressurized ion chamber agreed to within 13 percent. Attenuation studies with LiF TLDs indicated that roughly 25 percent of the total free air exposure rate at 1 m was due to beta radiation. (auth)

Albedo neutron dosimeters have proven to be effective as a method of measuring the dose from low-energy neutrons that other types of personnel neutron dosimeters do not detect. Many albedo neutron dosimeters have been designed, and some are being used extensively. All albedo neutron dosimeters are energy- dependent, becoming less sensitive as the energy of the neutrons is increased. In this paper the energy dependence and the effect it has on the evaluation of the dose are discussed. Numerous measurements are shown which were made under field conditions at five reactors, two accelerators, a radiochemistry facility, two plutonium facilities, a low-scatter neutron irradiation facility, three storage vaults, and at the N.B.S. low-energy neutron beams. These measurements show the limits imposed by the energy dependence on the evaluation of the dose determined by albedo neutron dosimeters. In most cases evaluation of an individual's dose occurring in a single facility can be reasonably accurate, but it must be known in which facility the person was exposed. Procedures using the incident thermal neutron response of TLDs located on top of the dosimeter to correct for the energy dependence are discussed; and errors caused by wearing a dosimeter improperly are evaluated. (auth)

The design and fabrication of a 1.1-m bore superconducting coil for an 8- T facility at Lawrence Livermore Laboratory are discussed. This facility will provide the backing field required for testing large multifilamentary Nb$sub 3$Sn coils as part of the superconductor development program at Livermore. The magnet measures 1.85 m o.d., is 1.5 m in length, and is solenoid wound in four separate modules. Total cold weight of the assembly is 18,000 Kg. A NbTi superconductor is used throughout with a gradation of current density within the magnet to provide complete cryostatic stability. The preliminary design of a large 3500-A multifilamentary Nb$sub 3$Sn insert magnet is also included. Together, the backing coil and insert magnets are designed to produce a 12-T central field in a 0.4m bore. The ''equal area'' theory of cryostatic stability is applied in the design of both magnet systems and is discussed in detail. A large open-mouth cryostat is used and measures 2 m in diameter and 3.7 m in length. Details of Dewar design and the refrigeration requirements are included. (auth)

The chief purpose of ARAC data acquisition program is to provide site officials, who are responsible for ensuring maximum health protection for the endangered site personnel and public, with estimates of the effects of atmospheric releases of hazardous material as rapidly and accurately as possible. ARAC is in the initial stages of being implemented and is therefore susceptible to changes before it reaches its final form. However the concept of ARAC is fully developed and was successfully demonstrated during a feasibility study conducted in June 1974, as a joint effort between the Savannah River Laboratory (SRL) and Lawrence Livermore Laboratory (LLL). Additional tests between SRL and LLL are scheduled for December 1975. While the immediate goal is the application of ARAC to assist a limited number of ERDA sites, the system is designed with sufficient flexibility to permit expanding the service to a large number of sites. Success in ARAC application should provide nuclear facilities with a means to handle better the urgent questions concerning the potential accidental hazards from atmospheric releases in addition to providing the sites with a capability to assess the effort of their normal operations. (CH)

An estimate is presented of the lifetime of the 2$sup 3$P$sub 0$ state for odd-Z heliumlike ions in the range Z = 9 to 29. An approximation scheme is employed which utilizes the fact that both Z$sup -1$ and (Z$alpha$)$sup 2$ are small parameters for the range of Z under consideration. 1 fig, 2 tables, 14 refs. (GHT)

All major plasma diagnostic measurements from the 2XIIB experiment are recorded, digitized, and stored by the computer data acquisition system. The raw data is then examined, correlated, reduced, and useful portions are quickly retrieved which direct the future conduct of the plasma experiment. This is done in real time and on line while the data is current. The immediate availability of this pertinent data has accelerated the rate at which the 2XII personnel have been able to gain knowledge in the study of plasma containment and fusion interaction. The up time of the experiment is being used much more effectively than ever before. This paper describes the hardware configuration of our data system in relation to various plasma parameters measured, the advantages of powerful software routines to reduce and correlate the data, the present plans for expansion of the system, and the problems we have had to overcome in certain areas to meet our original goals. (auth)

The uniformity of wire characteristics is vital to the reliable long- time operation of the titanium alloy wire. Of particular importance is the diameter, total emissivity, and alloy mix. The getter wire must be operated at a minimum rate while the life is determined by the maximum rate. At a particular current the difference between the maximum and minimum rate is determined by variations in wire characteristics. Small percentage variations in these characteristics can result in large variations in gettering rate. (auth)

The original manual control system for the 12 neutral beam injectors on the 2XIIB Machine is being integrated with a computer control system. This, in turn, is a part of a multiple computer network comprised of the three computers which are involved in the operation and instrumentation of the 2XIIB experiment. The computer control system simplifies neutral beam operation and centralizes it to a single operating position. A special purpose console utilizes computer generated graphics and interactive function entry buttons to optimize the human/ machine interface. Through the facilities of the computer network, a high level control function will be implemented for the use of the experimenter in a remotely located experiment diagnositcs area. In addition to controlling the injectors in normal operation, the computer system provides automatic conditioning of the injectors, bringing rebuilt units back to full energy output with minimum loss of useful life. The computer system also provides detail archive data recording. (auth)

A test stand is in operation at LLL for the purpose of developing techniques and obtaining design information which will be used to develop efficient neutral beams. The knowledge gained will be used in the design of a 200 kV neutral beam test stand scheduled for operation in CY 77. (auth)

A high-efficiency detector system developed especially for medical imaging has three specially cut Ge(Li) coaxial detectors (total volume 249 cm$sup 3$). At 122 keV, the peak efficiency is 93 percent of that of a 7.6 x 7.6 cm NaI (Tl) detector. Degradation of the paralleled energy resolution is avoided and resolution is improved by 35 percent over that of conventional output-summing techniques by gating the detector outputs. In effect this multiplexes them to a single line output. (auth)

Theoretical energy band structure calculations have been utilized to investigate several high-Z materials for potential use as ambient temperature radiation detectors. Using the pseudopotential technique, the band structure for HgI$sub 2$ has been determined and the effective masses of the holes and electrons have been estimated. Theoretical mobilities of the electrons and holes as a function of temperature have been computed for HgI$sub 2$ and CdTe and are compared to experimental data. (auth)

Results of recently concluded investigations of infrared laser induced photoionization of very high lying even parity levels in atomic uranium are presented. Behavior of both Rydberg and valence states is described.

High resolution (less than or equal to .5 cm/sup -1/) autoionization spectra of atomic uranium has been observed from newly identified odd parity levels between 32,660 and 34,165 cm/sup -1/. Photoionization cross sections are presented.

Over 100 new odd parity levels useful for isotope separation of U(I) were observed between 32,660--34,165 cm/sup -1/ using multistep photoionization. A tabulation of typical cross sections and radiative lifetimes for these states is given. The extension of this technique to mapping the spectra of other heavy atoms is discussed. (auth)

An analytic model of the fusion components is used to generate a consistent set of fusion parameters, and component costs as parameters are varied. A model of the blanket, based on neutronic and thermal hydraulics, is then used to analyze the trade-offs of energy production vs plutonium production dictated by blanket type and management. An economic discussion of fuel cost is also given. (MOW)

Separate abstracts were prepared for twenty-four papers. (MHR)

A brief description is given of modifications and additions to the existing Baseball II experiment. These changes will make it possible to study target plasma buildup in a steady-state magnetic field. This experiment, now called Baseball II-T$sup +$ will use a pellet generator to deliver ammonia pellets into the center of the magnetic mirror field where they will be heated with a 300-J, 50-ns, CO$sub 2$ laser. The plasma created by this method will have a density of approximately 10$sup 13$ cm$sup -3$ and a temperature of about 1 keV. This target plasma will be used for neutral beam injection startup studies with a 50-A, 20-keV neutral beam. Later, the beam power will be increased to study buildup. With ion injection energies of up to 50 keV, it may be possible to achieve etatau as high as 10$sup 12$ cm$sup -3$ s. The new components necessary to achieve these goals are described. (auth)

A computer program, EFFI, is described which calculates the electric and magnetic fields due to an arbitrary spatial distribution of current-carrying circular loops, circular arcs, and straight lines. The electric field is assumed to arise solely from the time variation of the magnetic field, and the magnetic field due to the changing electric field is assumed to be negligible. In addition, the conductor bundle elements (loops, arcs, lines) are assumed to be absent. Electric and magnetic flux lines and magnetic forces and inductances are also calculated by the program. The algorithm used in the code, which is based on a combination of direct and numerical integration using the Biot-Savart law, is discussed. The methods used to maintain accuracy in calculating fields within the conductor bundle, in particular, are detailed. Several examples are then presented to illustrate the input and output features as well as the accuracy obtained and the running time required. (auth)

The next generation of controlled thermonuclear reactor experiments will be faced with the handling problems of tritium and neutron activation that will dominate the safety and maintenance problems of future fusion reactors. The nuclear industry has been working with highly radioactive systems for many years and has developed the tools and methods to do safely productive work in the presence of high radiation fields. These methods can be applied to CTR work by extending them to the unique problems associated with fusion reactors. (auth)

At the Lawrence Livermore and Berkeley Laboratories two major neutral beam system designs were developed, the High Voltage Test Stand (HVTS) and a conceptual system for the Two Component Tokamak-Toroidal Fusion Test Reactor (TCT- TFTR). The HVTS was designed for flexibility in performing a wide variety of tests, while the TCT-TFTR beam line was designed to satisfy particular requirements for target-plasma operation. Both designs make use of condensation cryopumping to handle very high gas loads. The HVTS design involves high-voltage isolation techniques of cryogenic and other systems. The TCT-TFTR design requires optimization of pumping and other systems. It is to be expected that experience gained from design and operation of the HVTS systems will be of value to the final design of TCT-TFTR and to the engineering of future fusion reactors. (auth)

The design and operation of a 10-ps resolution optical streak camera used to characterize laser pulses and other transient optical signals in fusion research is discussed. Performance characteristics are presented. The design, operation, and application of an x-ray streak camera used to study laser-produced plasmas in the x-ray spectral region of 1 to 10 keV with temporal and spatial resolutions of approximately 20 ps and approximately 10 $mu$m is also discussed. (auth)