A boundary plasma turbulence code BOUT is presented. The preliminary encouraging results have been obtained when comparing with probe measurements for a typical Ohmic discharge in CT-7 tokamak. The validation and benchmark of BOUT code and experimental diagnostic tools for fusion boundary plasma turbulence is proposed.

Gravitinos with a mass in the keV range are an interesting candidate for warm dark matter. Recent measurements of the matter density of the universe and of cosmic structures at the dwarf galaxy scale rule out the simplest gravitino models with thermal freeze-out. We construct a model where the decay of the messenger particles that transmit the supersymmetry breaking to the observable sector generates the required entropy to dilute the gravitino relic density by the required factor of a few to come in line with observations. The model is natural, and requires only that the coupling of the messenger sector to the standard model be set so that the decay happens at the appropriate time.

We characterize the performance of a complete 64-pixel compact gamma camera imaging module consisting of optically isolated 3 mm 3 mm 5 mm CsI(Tl) crystals coupled to a custom array of low-noise Si PIN photodiodes read out by a custom IC. At 50 V bias the custom 64-pixel photodiode arrays demonstrate an average leakage current of 28 pA per 3 mm 3 mm pixel, a 98.5 percent yield of pixels with <100 pA leakage, and a quantum efficiency of about 80 percent for 540 nm CsI(Tl) scintillation photons. The custom 64-channel readout IC uses low-noise preamplifiers, shaper amplifiers, and a winner-take-all (WTA) multiplexer. The IC demonstrates maximum gain of 120 mV / 1000 e-, the ability to select the largest input signal in less than 150 ns, and low electronic noise at 8 ms peaking time ranging from 25 e- rms (unloaded) to an estimated 180 e- rms (photodiode load of 3 pF, 50 pA). At room temperature a complete 64-pixel detector module employing a custom photodiode array and readout IC demonstrates an average energy resolution of 23.4 percent fwhm and an intrinsic spatial resolution of 3.3 mm fwhm for the 140 keV emissions of 99mTc. Construction of an array …

Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. to support detection instruments, they are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. They are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Many of these fluidic functions are accomplished with acoustic radiation pressure or dielectrophoresis. They are integrating these technologies into packaged systems with pumps and valves to control fluid flow through the fluidic circuit.

Recent development in geophysical methods allows us to accurately map the distribution of seismic velocity, density and electrical conductivity beneath the surface and between boreholes. These physical properties are dependent on porosity, fluid saturation, fluid conductivity, pressure, temperature, clay content, and in some circumstances, permeability. Hydrological parameters may be measured or inferred from drill hole experiments or directly from core samples. The point measurements in a drill hole are then interpolated to the interwell volume using either statistical properties of the local geology or reasonable estimates of the geological structure and lithology. More direct evidence is obtained from well tests, and interference tests between multiple wells, but these are ill posed inverse problems when it comes to defining the properties of the entire interwell volume. Furthermore such tests are impossible in the vadose zone. The interpolation of well data is often inaccurate or misleading and the central problem for all these studies is the lack of these fundamental parameters throughout the subsurface volume of interest.

A sudden drop in power after a beam interruption leads to thermal fatigue effects in structural components in the blanket of an accelerator driven system. These thermal fatigue effects limit component lifetimes. A sudden return to power after a beam interruption can contribute significant additional thermal fatigue and greatly reduce component lifetimes. One obvious solution is a gradual return to power after a beam interruption. There are two potential problems with this solution. One problem involves interruptions that are longer than the thermal time constants of thin structural members but shorter than the time constants of thick structural members. In such a case, a gradual return to power reduces the additional thermal fatigue in the thin structural members but increases the thermal fatigue in thick structural members. Some compromise is necessary. The other problem is that for thick components with long thermal time constants a long, gradual return to power is required to minimize additional thermal fatigue. Such a slow return to power can reduce the utilization or the effective load factor of the system. Specific examples of beam interruptions with various assumptions on return to power are provided for a preliminary design for the blanket of the Accelerator Driven …

Many of today's automated real-time testing systems for embedded systems were developed using expensive custom hardware and software. In this article they describe how to use commercially available off-the-shelf hardware and software to design and develop an automated real-time test systems for Embedded Programmable Logic Controller (PLC) Based Control Systems. The system development began with the implementation of the VALI/TEST Pro testing methodology as a means for structuring the testing. Using this methodology, they were able to decompose system requirement documents for a Personnel Safety System (PSS) into its high, intermediate and detail level requirements. next, the validation procedures for the PSS system were decomposed into testing units called builds, test runs and test cases. To measure the PSS system's test coverage three levels of system requirements were mapped to their respective unit level of test using a specially constructed validation matrix that was designed to handle over 150 test cases and requirements. All of the above work led to the development of an Automated Real-Time Test System (ARTTS) that is capable of performing complete black box testing in real-time for Embedded PLC Based Control Systems. Also note, that the PSS system under test and mentioned in this paper is …