The Mirrortron accelerator is a plasma-based ion accelerator concept that, when implemented, should permit both higher acceleration gradients and higher peak-current capabilities than is possible with conventional induction-type accelerators. Control over the acceleration and focussing of an accelerated beam should approach that achieved in vacuum-field-based ion accelerators. In the Mirrortron a low density (10{sup 10} to 10{sup 11} cm{sup {minus}3}) hot electron'' plasma is confined by a long solenoidal magnetic field capped by mirrors''. Acceleration of prebunched ions is accomplished by activating a series of fast-pulsed mirror coils spaced along the acceleration tube. The hot electrons, being repelled by mirror action, leave the plasma ions behind to create a localized region of high electrical gradient (up to of order 100 MV/m). At the Laboratory an experiment and analyses to elucidate the concept and its scaling laws as applied to heavy-ion drivers are underway and will be described. 4 refs., 5 figs.

As the systems engineering activities at the US Department of Energy`s Hanford reservation have matured, they have been placed in many positions within the management structure. Some of these have been more successful than others. This paper describes the organizational evolution of systems engineering over the last few years to its current successful configuration. Background The US Department of Energy (DOE) owns the 640 square mile Hanford reservation located in southeast Washington State (Figure 1). The Site has been operated for DOE by a team of contractors, who read like a Who`s Who in American Industry. Throughout its history from its founding in 1943 until 1991, Hanford`s primary mission was to produce special nuclear material for the nuclear weapons program. This mission resulted in significant quantities of radioactive and mixed waste that is stored on the site in a variety of forms. In addition much of the surface area, subsurface soil, and groundwater are contaminated to various degrees. The Reservation is located on the banks of the Columbia River, and the avoidance of contaminating the waterway that services the Pacific Northwest is a national concern. In 1991, the mission of the Hanford Site was changed from production to environmental cleanup. …

Large volumes of hydrocarbons are stored worldwide in surface and underground tanks. It is well documented [1] that all too often these tanks are found to leak, resulting in not only a loss of stored inventory but, more importantly, contamination to soil and groundwater. Two field experiments are reported herein to evaluate the utility of electrical resistance tomography (ERT) for detecting and locating leaks as well as delineating any resulting plumes emanating from steel underground storage tanks (UST). Current leak detection methods for single shell tanks require careful inventory monitoring, usually from liquid level sensors within the tank, or placement of chemical sensors in the soil under and around the tank. Liquid level sensors can signal a leak but are limited in sensitivity and, of course, give no information about the location or the leak or the distribution of the resulting plume. External sensors are expensive to retrofit and must be very densely spaced to assure reliable detection, especially in heterogeneous soils. The rational for using subsurface tomography is that it may have none of these shortcomings.

The ''Cold War'' was not fought only by soldiers but by scientists and engineers in Laboratories and plants located throughout the world. With the fall of the Berlin Wall, the ''Cold War'' was effectively over, but the weapons of nuclear war remained. Following signing of START 2 (Strategic Arms Reduction Treaty) in 1993, up to 100 tonnes of weapons usable plutonium is expected to be declared excess by the Super Powers. Steps must be taken to address the proliferation risks associated with this plutonium. Again the scientist and engineers, who were the ''Cold War'' warriors, are being asked to develop methods to disposition this plutonium such that it can never again be used for weapons. Will we burn the plutonium in reactors or immobilize the plutonium either in a glass or ceramic matrix? Interesting challenges face chemists and chemical engineers developing immobilization techniques to render the plutonium both environmentally benign, and proliferation resistant.

Field emission cathodes (FECs) with characteristics of cold emission, low voltage operation, high current density and microscopic size meet the requirements for an electron source for use in vacuum microelectronics. Deposition efforts have focused on evaporation techniques, as electron beam, to produce the size and shape of cathode required for efficient operation. After two decades of development, the convention for FEC synthesis involves coating with very high tolerances for thickness uniformity using a planetary substrate fixture and a long source-to-substrate distance. A further reduction in the operating voltage results by increasing the density of emitters through a reduction of cathode size and spacing. In addition, the objective of scaling the substrate size from small to large areas has compounded the manufacturing requirements to a point beyond that which is obtainable through modifications to the conventional FEC deposition process. We have been successful in a new alternative approach to design, assemble and operate a system that enables FEC synthesis over large areas through the control of deposition source divergence and step-and-repeat substrate handling.

Infrared computed tomography (IRCT) is a promising, non-contact, nondestructive evaluation tool used to inspect the mechanical integrity of large structures. We describe on-site, proof-of-principle demonstrations of IRCt to inspect defective metallic and composite structures. The IRCT system captures time sequences of heat-stimulated, dual-band infrared (DBIR) thermal maps for flash-heated and naturally-heated targets. Our VIEW algorithms produce co-registered thermal, thermal inertia, and thermal-timegram maps from which we quantify the percent metal-loss corrosion damage for airframes and the defect sites, depths, and host-material physical properties for composite structures. The IRCT method clarifies the type of defect, e.g., corrosion, fabrication, foreign-material insert, delamination, unbond, void, and quantifies the amount of damage from the defect, e.g., the percent metal-loss from corrosion in metal structures, the depth, thickness, and areal extent of heat damage in multi-layered composite materials. Potential long-term benefits of IRCT technology are in-service monitoring of incipient corrosion damage, to avoid catastrophic failure and production-monitoring of cure states for composite materials.

This paper makes a case for the use of participatory ergonomics by and for ergonomists. A strategy for using participatory ergonomics in a conference workshop format is described. The process could be used as a tool for issues of common concern among ergonomists. it would also offer an experience of the participatory ergonomics process. An example workshop on quantifying costs and benefits of ergonomics is discussed.

Risk ranking schemes have been used in safety analysis to distinguish lower risk accidents from higher risk accidents. This is necessary to identify those events that might warrant additional study or quantitative analysis and to ensure that any resources allocated for risk reduction are properly directed. A common method used for risk ranking utilizes risk matrices. These are typically 3x3 or 4x4 matrices having event consequences along one axis and event frequency along the other. Each block on the risk matrix represents some level of risk, and blocks presenting similar risk are often grouped together into one of three or four risk regions. Once a risk matrix has been identified, events are placed on the matrix based on an estimate of the event consequence and event frequency. Once the risk of each block on the matrix is defined, the relative risk of the events can be found based on where they are placed on the matrix. In most cases, the frequency axis of the matrix has numerical values associated with it, typically spanning several orders of magnitude. Often, the consequence axis is based on a qualitative scale, where consequences are judgment based. However, the consequence scale generally has implicit quantitative …

The Lawrence Livermore National Laboratory has developed radar and imaging technologies with potential application in demining efforts. A patented wideband (impulse) radar that is very compact, very low cost, and very low power, has been demonstrated in test fields to be able to detect and image nonmetallic land mines buried in 2-10 cm of soil. The scheme takes advantage of the very short radar impulses and the ability to form a large synthetic aperture with many small individual units, to generate high resolution 2-D or 3-D tomographic images of the mine and surrounding ground. Radar range calculations predict that a vehicle-mounted or man-carried system is quite feasible using this technology. This paper presents the results of field tests using a prototype unit and describes practical mine detection system concepts. Predicted capabilities in terms of stand-off range and radiated power requirements are discussed.

Magnetic Circular X-ray Dichroism (MCXD) studies at K edges of Fe-Ni alloys reveal changes of the MCXD signal with composition and crystal structure. We observe that the signal at the invar composition is of comparable strength as other compositions. Moreover, the edge position is strongly dependent on lattice constant. First principles calculations demonstrate that the shape and strength of the signal strongly depends on the crystal orientation, composition, and lattice constant. We find direct relation between the MCXD signal and the p DOS. We find that the MCXD at K edge probes the magnetism due to itinerant electrons.

This paper presents an overview of the hardware and software proposed for the ATLAS level 2 Trigger ROI Builder/Supervisor. The essential requirements of this system are that it operate at the design Level 1 Trigger rate of 100kHz and that it support the technical requirements of the architectures suggested for the ATLAS Level 2 Trigger. Commercial equipment and software support are used to the maximum extent possible, with support from dedicated hardware. Timing requirements and latencies are discussed and simulation results are presented.