64 research outputs found

    On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

    Get PDF
    A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)

    Overview of the JET results in support to ITER

    Get PDF

    Building a Sibling Aggression Treatment Model: Design and Development Research in Action

    No full text
    One strategy for addressing the persistent challenge of advancing empirically based social work practice is to engage practitioners in the formulation of empirically developed practice guidelines. Although this approach is promising, there has been relatively little work to guide practitioners, and perhaps consequently, few examples of practitioner-developed guidelines exist. Moreover, available treatment models do not address most social work practice concerns. One such concern involves sibling aggression, which is exceptionally widespread with known deleterious consequences, but it has received scant attention in the intervention literature. This article illustrates a practitioner\u27s development of a task-centered sibling aggression treatment model using the design and development research paradigm, a methodology for systematically formulating, testing, and refining practice guidelines. It also introduces a promising sibling aggression treatment model
    corecore