DIII-D physics research addresses critical challenges for the operation of ITER and the next generation of fusion energy devices. This is done through a focus on innovations to provide solutions for high performance long pulse operation, coupled with fundamental plasma physics understanding and model validation, to drive scenario development by integrating high performance core and boundary plasmas. Substantial increases in off-axis current drive efficiency from an innovative top launch system for EC power, and in pressure broadening for Alfven eigenmode control from a co-/counter- I p steerable off-axis neutral beam, all improve the prospects for optimization of future long pulse/steady state high performance tokamak operation. Fundamental studies into the modes that drive the evolution of the pedestal pressure profile and electron vs ion heat flux validate predictive models of pedestal recovery after ELMs. Understanding the physics mechanisms of ELM control and density pumpout by 3D magnetic perturbation fields leads to confident predictions for ITER and future devices. Validated modeling of high- Z shattered pellet injection for disruption mitigation, runaway electron dissipation, and techniques for disruption prediction and avoidance including machine learning, give confidence in handling disruptivity for future devices. For the non-nuclear phase of ITER, two actuators are identified to lower the L–H threshold power in hydrogen plasmas. With this physics understanding and suite of capabilities, a high poloidal beta optimized-core scenario with an internal transport barrier that projects nearly to Q = 10 in ITER at ∼ 8 MA was coupled to a detached divertor, and a near super H-mode optimized-pedestal scenario with co- I p beam injection was coupled to a radiative divertor. The hybrid core scenario was achieved directly, without the need for anomalous current diffusion, using off-axis current drive actuators. Also, a controller to assess proximity to stability limits and regulate β N in the ITER baseline scenario, based on plasma response to probing 3D fields, was demonstrated. Finally, innovative tokamak operation using a negative triangularity shape showed many attractive features for future pilot plant operation.

In this paper we consider the problem of autoconfiguring nodes in an airborne wireless network. The airborne platforms consist of routers as well as one or more hosts. External links from the airborne platform employ directional transmit beams. We expect the nodes to join or leave the network without pre-planning or manual configuration. Additionally we expect the users and applications of this network to discover available services in an automated manner. In this paper we present protocols that allow autoconfiguration of IPv6 addresses and names, as well as the automated discovery of services within the airborne wireless network.

The integration of electronic routing functions with WDM functions in network elements capable of reconfiguration over short time scales enables access networks to efficiently service time varying demand. An effective coordination of electronic and WDM network functions allows traffic to bypass electronic to optical conversion within the access network. The cost benefits derived from reduced transponder use due to this coordination can result in lower cost access for end users. The transparency of WDM also allows heterogeneous traffic formats to be carried over a common fiber. In this paper, we describe a reconfigurable WDM access network testbed that incorporates features outlined above. This testbed was used in demonstrating network functions such as dynamic lightpath provisioning, packet flow-switching, and remote amplification for supporting large numbers of end users. The testbed network incorporates protection switching and network control capabilities. The testbed network also provides connectivity to an in-ground long haul network. The testbed architecture and description of networking experiments demonstrating its capabilities are presented. The throughput degradation due to optical flow switching for Transport Control Protocol (TCP) data transmissions over large bitrate-delay product links is characterized. Adding the Eifel Algorithm to the TCP implementation restored performance. The performance of a remotely pumped EDFA for serving many users in the collection/distribution network is also presented.

We create hot ( T e > 200 eV) and dense ( N e > 10 23 cm −3 ) plasmas in the colliding zone of two thin foils accelerated by two laser beams of the LULI facilities. Three spectroscopic diagnostics (two 1D space-resolved spectrographs and a 2D monochromatic imaging) are used to drive the efficiency of the compression. We show that 2D effects are important. Realistic simulations of these experiments must be done, taking into account the inhomogeneity of the laser intensity in the focal spot, the foil distorsion, the plasma lateral expansion, and the lateral thermal conduction. Two-dimensional LASNEX code results are in good agreement with our experimental results. The optimized compressed plasmas generated are favorable for the exhibition of dense plasma effects due to molecular formations, and they reproduce in laboratory some astrophysical situations.

The collision of two plasmas produced from laser-exploded Al/Al and Al/Mg foils has been studied by x-ray diagnostics over a wide range of experimental conditions. Ion temperatures of about 10 keV have been unambiguously inferred from Doppler broadening. The interpenetration distances have been determined by the spatial extent of Mg and Al ion emission. The comparison of experimental data with multifluid and atomic physics simulations gives a good understanding of the localization and dynamics of the kinetic to thermal energy transfer in the interpenetration regime.

Scheduling guarantees are essential in many real-time embedded computer systems. They can only be achieved by performing analysis of scheduling feasibility prior to run-time. This paper examines some issues related to this problem in the context of hardware architectures that are more complex than a single bus linking several processors. It raises questions about how well existing static scheduling and schedulability analysis techniques scale up to the larger systems that are likely to be in use in the future

The authors present a systematic approach to modeling the timing behavior of hard real-time (HRT) control algorithms. Parallel computers have increasingly been used in the implementation of large digital control systems. The dynamic environment surrounding complex HRT systems requires that the parallel computer architecture be flexible and able to support different technologies, including heterogeneous processor sets. A general formulation of scheduling models for digital and robotic control systems is described. A scheduling tool is presented for managing the complexity of nonpreemptive scheduling and allocation of HRT tasks to homogeneous and heterogeneous processor sets. The scheduling algorithms and the implementation of the scheduling tool are discussed. The test cases used to validate the proposed algorithms and the results obtained from these tests are presented.<>

The authors investigate four different concepts which are candidates to resolve the hidden surface removal problem without the use of priorities. All four are based on determining a linear depth order consistent with the partial order of primitives in a span. A span is a small subimage of the image being generated. The first approach examines parallel sorting of all the depth values of all primitives in a span. The second approach, for each pixel in a span, builds a list of all the primitives in that span, totally ordered by depth. These lists represent the partial order of the primitives, and are later enumerated to give a total order. The third approach performs up to k pairwise comparisons in parallel between primitives to determine if a depth relationship exists. If one exists, the pair is stored in a partial order graph which is later enumerated to create a total order. The fourth approach involves the use of a pipeline of length k, which, at any given time, contains up to k primitives which are closest. If there are more than k primitives in a span, more than one iteration is needed. The fourth approach appears to be the most promising, even though there are situations in which it generates an incorrect ordering

Recent Lower Hybrid Current Drive (LHCD) experiments in TORE SUPRA and JET are reported. Large multijunction launchers have allowed the coupling of 5 MW to the plasma for several seconds with a maximum of 3.8 kw/cm2. Measurements of the scattering matrices of the antennae show good agreement with theory. The current drive efficiency in TORE SUPRA is about 0.2 x 10(20) Am-2/W with LH power alone and reaches 0.4 x 10(20) Am-2/W in JET thanks to a high volume-averaged electron temperature (1.9 keV) and also to a synergy between Lower Hybrid and Fast Magnetosonic Waves. At N(e)BAR = 1.5 x 10(19) m-3 in TORE SUPRA, sawteeth are suppressed and m = 1 MHD oscillations the frequency of which clearly depends on the amount of LH power are observed on soft x-rays, and also on non-thermal ECE. In JET ICRH produced sawtooth-free periods are extended by the application of LHCD (2.9 s. with 4 MW ICRH) and current profile broadening has been clearly observed consistent with off-axis fast electron populations. LH power modulation experiments performed in TORE SUPRA at N(e)BAR = 4 x 10(19) m-3 show a delayed central electron heating despite the off-axis creation of suprathermal electrons, thus ruling out the possibility of a direct heating through central wave absorption. A possible explanation in terms of anomlous fast electron transport and classical slowing down would yield a diffusion coefficient of the order of 10 m2/s for the fast electrons. Other interpretations such as an anomalous heat pinch or a central confinement enhancement cannot be excluded. Finally, successful pellet fuelling of a partially LH driven plasma was obtained in TORE SUPRA, 28 successive pellets allowing the density to rise to N(e)BAR = 4 x 10(19) m-3. This could be achieved by switching the LH power off for 90 ms before each pellet injection, i.e. without modifying significantly the current density profile.

Tungiasis is a cutaneous parasitic infestation by the fertilized female sand flea Tunga penetrans. It is prevalent in tropical Africa and in Central and South America. Despite increasing air travel to and from these countries, surprisingly the disease is rarely reported in the United States. This report describes another case of tungiasis and reviews the 14 previously reported cases in the United States. Clinical features, differential diagnosis, treatment, and prophylaxis of tungiasis are discussed.

Mode‐converted and directly excited ion Bernstein waves (IBW) were studied using CO2 laser scattering in the Alcator C tokamak. During the ICRF fast wave heating experiments, mode‐converted IBW was observed on the high‐field side of the resonance in both second harmonic and minority heating regimes. By comparing the relative scattered powers from the two antennas separated by 180° toroidally, an increased toroidal wave damping with increasing density was inferred. In the IBW heating experiments, optimum direct excitation is obtained when an ion‐cyclotron harmonic layer is located just behind the antenna. Wave absorption at the ω=3ΩD=1.5ΩH layer was directly observed. Edge ion heating was inferred from the IBW dispersion when this absorption layer was located in the plasma periphery, which may be responsible for the observed improvement in particle confinement.