[en] A device for detecting ionising radiation and measuring its intensity is claimed. It comprises a sealed vessel enclosing dry air or other gas. Two conducting surfaces, one fixed, the other pivoted, are suspended in the gas. They are supported in such a manner that a static charge can be transferred to them from a charged body without but the same charge cannot return except through the enclosed gas. The electrical conductivity of the gas is affected by the presence of ionising radiation in proportion to its strength

[en] This report is a compilation of the three annual progress reports. All detail can be found in the refereed publications enumerated within

No abstract available

[en] ITER will depend on high power CW gyrotrons to deliver power to the plasma at ECR frequencies. However, gyrotrons can suffer from undesirable low frequency oscillations (LFO's) which are known to interfere with the gun-region diagnostics and data collection, and are also expected to produce undesirable energy and velocity spread in the beam. The origins and processes leading to these oscillations are poorly understood, and existing gyrotron R and D tools, such as static gun solvers and interaction region models, are not designed to look at time-dependant oscillatory behavior. We have applied a time-domain particle-in-cell method to investigate the LFO phenomenon. Our company is at the forefront of smooth-curved-boundary treatment of the electromagnetic fields and particle emission surfaces, and such methods are necessary to simulate the adiabatically trapped and reflected electrons thought to be driving the oscillations. This approach provides the means for understanding, in microscopic detail, the underlying physical processes driving the low-frequency oscillations. In the Phase I project, an electron gun region from an existing gyrotron, known to observe LFO's, was selected as a proof-of-principle geometry, and was modeled with the curved-geometry time-domain simulation tool, in order to establish the feasibility of simulating LFO physics with this tool on office-scale, and larger, parallel cluster computers. Generally, it was found to be feasible to model the simulation geometry, emission, and magnetic features of the electron gun. Ultimately, the tool will be used to investigate the origins and life cycle within the trapped particle population. This tool also provides the foundations and validation for potential application of the software to numerous other time-dependant beam and rf source problems in the commercial arena.

No abstract available

[en] Accelerator facility upgrades, new accelerator applications, and future design efforts are leading to novel klystron and IOT device concepts, including multiple beam, high-order mode operation, and new geometry configurations of old concepts. At the same time, a new simulation capability, based upon finite-difference 'cut-cell' boundaries, has emerged and is transforming the existing modeling and design capability with unparalleled realism, greater flexibility, and improved accuracy. This same new technology can also be brought to bear on a difficult-to-study aspect of the energy recovery linac (ERL), namely the accurate modeling of the exit beam, and design of the beam dump for optimum energy efficiency. We have developed new capability for design calculations and modeling of a broad class of devices which convert bunched beam kinetic energy to RF energy, including RF sources, as for example, klystrons, gyro-klystrons, IOT's, TWT's, and other devices in which space-charge effects are important. Recent advances in geometry representation now permits very accurate representation of the curved metallic surfaces common to RF sources, resulting in unprecedented simulation accuracy. In the Phase I work, we evaluated and demonstrated the capabilities of the new geometry representation technology as applied to modeling and design of output cavity components of klystron, IOT's, and energy recovery srf cavities. We identified and prioritized which aspects of the design study process to pursue and improve in Phase II. The development and use of the new accurate geometry modeling technology on RF sources for DOE accelerators will help spark a new generational modeling and design capability, free from many of the constraints and inaccuracy associated with the previous generation of 'stair-step' geometry modeling tools. This new capability is ultimately expected to impact all fields with high power RF sources, including DOE fusion research, communications, radar and other defense applications.

[en] BaBar has recently deployed a new event data format referred to as the Mini. The mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per event. The Mini currently uses Objectivity persistence, and it is being ported to use Root persistence. The Mini contains enough information to support detailed detector studies, while remaining small and fast enough to be used directly in physics analysis. Mini output is customizable, allowing users to both truncate unnecessary content or add content, depending on their needs. The Mini has now replaced three older formats as the primary output of BaBar event reconstruction. A reduced form of the Mini will soon replace the physics analysis format as well, giving BaBar a single, flexible event data format covering all its needs

[en] We present preliminary evidence of BCS diquark condensation in the 3 + 1 dimensional Nambu-Jona-Lasinio (NJL) model at non-zero chemical potential (μ) on the lattice. Large N results are used to match the model's parameters to low energy, zero density phenomenology. A diquark source j is added in a partially quenched approximation to enable the measurement of lattice diquark observables. In particular measurements are made of the diquark condensate and susceptibilities as functions of j which support the existence of a BCS phase at high μ

[en] The paper presents some examples of the use of remote sensing products for characterization of hazardous waste sites. The sites are located at the Los Alamos National Laboratory (LANL) where materials associated with past weapons testing are buried. Problems of interest include delineation of strata for soil sampling, detection and delineation of buried trenches containing contaminants, seepage from capped areas and old septic drain fields, and location of faults and fractures relative to hazardous waste areas. Merging of site map and other geographic information with imagery was found by site managers to produce useful products. Merging of hydrographic and soil contaminant data aided soil sampling strategists. Overlays of suspected trench on multispectral and thermal images showed correlation between image signatures and trenches. Overlays of engineering drawings on recent and historical photos showed error in trench location and extent. A thermal image showed warm anomalies suspected to be areas of water seepage through an asphalt cap. Overlays of engineering drawings on multispectral and thermal images showed correlation between image signatures and drain fields. Analysis of aerial photography and spectral signatures of faults/fractures improved geologic maps of mixed waste areas

[en] Unfortunately, areas of waste disposal at DOE sites are not all documented and located. There are a number of reasons for this situation: records have been lost or destroyed, the locations were not documented, and memories have been lost. The search of large areas at these sites for buried waste and buried-waste containers is a difficult and expensive problem when using conventional, ground-based methods. Typical conventional methods involve the drilling of wells/boreholes (point sampling), and interpolation is required to obtain the needed a real information. Drilling for buried waste is expensive, potentially hazardous, and time-consuming, yet accurate interpolation can require a large number of holes per-unit-area. A similar problem is encountered in gaining current information about: the boundaries of toxic waste plumes in the ground, transport pathways, and the composition and concentration of toxic materials. The purpose of this effort is to analyze existing imagery data collected under various Department of Energy and other programs. This analysis will be useful for screening, characterization, and monitoring work in the waste site remediation process