Lithium wall coatings have been shown to reduce recycling, suppress edge-localized modes (ELMs), and improve energy confinement in the National Spherical Torus Experiment (NSTX). Here we document the effect of gradually increasing lithium wall coatings on the discharge characteristics, with the reference ELMy discharges obtained in boronized, i.e. non-lithiated conditions. We observed a continuous but not quite monotonic reduction in recycling and improvement in energy confinement, a gradual alteration of edge plasma profiles, and slowly increasing periods of ELM quiescence. The measured edge plasma profiles during the lithium-coating scan were simulated with the SOLPS code, which quantified the reduction in divertor recycling coefficient from ∼98% to ∼90%. The reduction in recycling and fuelling, coupled with a drop in the edge particle transport rate, reduced the average edge density profile gradient, and shifted it radially inwards from the separatrix location. In contrast, the edge electron temperature (T e) profile was unaffected in the H-mode pedestal steep gradient region within the last 5% of normalized poloidal flux, ψ N ; however, the T e gradient became steeper at the top of the H-mode pedestal for 0.8 < ψ N < 0.94 with lithium coatings. The peak pressure gradients were comparable during ELMy and ELM-free phases, but were shifted away from the separatrix in the ELM-free discharges, which is stabilizing to the current-driven instabilities thought to be responsible for ELMs in NSTX.

Joint experiment/theory/modelling research has led to increased confidence in predictions of the pedestal height in ITER. This work was performed as part of a US Department of Energy Joint Research Target in FY11 to identify physics processes that control the H-mode pedestal structure. The study included experiments on C-Mod, DIII-D and NSTX as well as interpretation of experimental data with theory-based modelling codes. This work provides increased confidence in the ability of models for peeling-ballooning stability, bootstrap current, pedestal width and pedestal height scaling to make correct predictions, with some areas needing further work also being identified. A model for pedestal pressure height has made good predictions in existing machines for a range in pressure of a factor of 20. This provides a solid basis for predicting the maximum pedestal pressure height in ITER, which is found to be an extrapolation of a factor of 3 beyond the existing data set. Models were studied for a number of processes that are proposed to play a role in the pedestal n e and T e profiles. These processes include neoclassical transport, paleoclassical transport, electron temperature gradient turbulence and neutral fuelling. All of these processes may be important, with the importance being dependent on the plasma regime. Studies with several electromagnetic gyrokinetic codes show that the gradients in and on top of the pedestal can drive a number of instabilities.

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Recently in the National Spherical Torus Experiment (NSTX), increasing lithium wall coatings suppressed edge localized modes (ELMs), gradually but not quite monotonically. This work details profile and stability analysis as ELMs disappeared throughout the lithium scan. While the quantity of lithium deposited between discharges did not uniquely determine the presence of ELMs, profile analysis demonstrated that lithium was correlated with wider density and pressure pedestals with peak gradients farther from the separatrix. Moreover, the ELMy and ELM-free discharges were cleanly separated by their density and pedestal widths and peak gradient locations. Ultimately, ELMs were only suppressed when lithium caused the density pedestal to widen and shift inward. These changes in the density gradient were directly reflected in the pressure gradient and calculated bootstrap current. This supports the theory that ELMs in NSTX are caused by peeling and/or ballooning modes, as kink/peeling modes are stabilized when the edge current and pressure gradient shift away from the separatrix. Edge stability analysis using ELITE corroborated this picture, as reconstructed equilibria from ELM-free discharges were generally farther from their kink/peeling stability boundaries than ELMy discharges. We conclude that density profile control provided by lithium is the key first step to ELM suppression in NSTX.

The need for physicians to have patient-centered communication skills is reflected in the educational objectives of numerous medical schools' curricula and in the competencies required by groups such as the Accreditation Council for Graduate Medical Education. An innovative method for teaching communications skills has been developed at the University of Colorado School of Medicine as part of its three-year, longitudinal course focusing on basic clinical skills required of all physicians. The method emphasizes techniques of open-ended inquiry, empathy, and engagement to gather data. Students refer to the method as ILS, or Invite, Listen, and Summarize. ILS was developed to combat the high-physician-control interview techniques, characterized by a series of "yes" or "no" questions. The authors began teaching the ILS approach in 2001 as one basic exercise and have since developed a two-year longitudinal communications curriculum. ILS is easy to use and remember, and it emphasizes techniques that have been shown in other studies to achieve the three basic functions of the medical interview: creating rapport, collecting good data, and improving compliance. The skills are taught using standardized patients in a series of four small-group exercises. Videotaped standardized patient encounters are used to evaluate the students. Tutors come from a variety of disciplines and receive standardized training. The curriculum has been well received. Despite the fact that the formal curriculum only occurs in the first two years, there is some evidence that it is improving students' interviewing skills at the end of their third year.