Suppression of anomalous impurity transport in NBI-heated W7-X plasmas

Radial impurity density profiles in two Wendelstein 7-X (W7-X) experiments heated by neutral beam injection (NBI) are analyzed with respect to their impurity transport properties. Local impurity densities are derived from charge exchange reactions with the W7-X NBI system using simulated neutral densities cross-validated with beam emission spectroscopy. Impurity profiles of argon and carbon are found to show an evolving central accumulation inside half radius. The properties of the underlying impurity transport are assessed using the one-dimensional transport code pySTRAHL. Comparisons between simulation and experiment indicate transport dominated by anomalous diffusion outside half radius. The observed central impurity accumulation is found to match best simulations with purely (neo-)classical transport in the accumulation region. This data implies a suppression of the anomalous impurity transport channel to below 35% of the (neo-)classical one. Experimental data is found to be matched best when invoking a time evolving, inward propagating zone where anomalous impurity transport is suppressed. An additional central power deposition into a plasma with central impurity accumulation via electron cyclotron resonance heating is found to affect the (neo-)classical transport components in case of operation times below 200 ms only. For longer operation times, it is found to re-introduce an altered level of anomalous diffusion. The existence of an inward directed anomalous pinch as an alternative explanation for the central impurity accumulation cannot explain the observed profiles

Pediatric collaborative care outcomes in a regional model

BackgroundDespite the movement toward hospital-based medical centers acquiring pediatric primary care offices, many primary care pediatricians still work in small, independent practices. To expand mental healthcare access, service delivery models must consider primary care practice needs and regionally available resources.ObjectiveThis report describes the implementation and evaluation of the Mood, Anxiety, ADHD Collaborative Care (MAACC) program over a 4 years period. MAACC. MAACC engaged 97 pediatric primary care clinicians across 39 practices in mental health training and supported the treatment of referred patients through a collaborative care model. To support psychosocial treatment needs, we built a child community therapy referral network of 213 licensed psychotherapy providers.MethodsData were collected on service delivery patterns (e.g., referrals, treatment use, and attrition) and patient outcomes. Measures included parent and children and adolescents PROMIS anxiety and depression short forms and the Parent NICHQ Vanderbilt.ResultsSix hundred ninety-six children and adolescents aged 6–18 were evaluated and provided treatment recommendations. Anxiety disorders were the most common diagnosis (45.4%), followed by ADHD (30.7%) and mood disorder (17%). For children and adolescents with an anxiety or mood disorder, significant improvement was observed from baseline to any initial follow-up and from baseline to 6, 12-, and 18 weeks on children and adolescents and parent measures of anxiety and depression. For children and adolescents with ADHD, significant improvement was observed from baseline to any initial follow-up measure and at 6 and 18 weeks on parent-reported inattentive symptoms. Significant differences in treatment outcomes were identified for children and adolescents with anxiety receiving psychotherapy alone and medication management and psychotherapy.ConclusionMAACC utilization and patient outcomes suggest that real-world collaborative care can effectively provide high-quality care while cultivating increased primary care treatment capacity and building on existing community resources

EMC3-EIRENE simulation of first wall recycling fluxes in W7-X with relation to H-alpha measurements

In the Wendelstein 7-X stellarator, the main locations of particle sources are expected to be the carbon divertors, baffles and graphite heat shield first wall. In this paper, the heat shield is implemented in EMC3-EIRENE to understand the expected areas and magnitudes of the recycling flux to this component. It is found that in the simulation the heat shield is not a significant source of recycling neutrals. The areas of simulated recycling flux are shown to correlate well with footprints of plasma-wetting seen in post-experimental campaign in-vessel inspection photos. EMC3-EIRENE reconstruction of line-integrated H-alpha measurements at the heat shield indicate that the majority of emission does not come from local recycling neutrals. Rather, the H-alpha signals at the heat shield are dominated by ionization of neutrals which have leaked from the divertor/baffle region into the midplane. The magnitude of the H-alpha line emission from the synthetic reconstruction is consistent with the experiment, indicating that a large overestimation of heat shield recycling would occur if these measurements were assumed to be from local recycling sources. In the future, it may be possible to obtain some information of local recycling from the heat shield since it was found that the majority of the recycling flux occurs on two well-localized areas

ATP synthase: from single molecule to human bioenergetics

ATP synthase (FoF1) consists of an ATP-driven motor (F1) and a H+-driven motor (Fo), which rotate in opposite directions. FoF1 reconstituted into a lipid membrane is capable of ATP synthesis driven by H+ flux. As the basic structures of F1 (α3β3γδε) and Fo (ab2c10) are ubiquitous, stable thermophilic FoF1 (TFoF1) has been used to elucidate molecular mechanisms, while human F1Fo (HF1Fo) has been used to study biomedical significance. Among F1s, only thermophilic F1 (TF1) can be analyzed simultaneously by reconstitution, crystallography, mutagenesis and nanotechnology for torque-driven ATP synthesis using elastic coupling mechanisms. In contrast to the single operon of TFoF1, HFoF1 is encoded by both nuclear DNA with introns and mitochondrial DNA. The regulatory mechanism, tissue specificity and physiopathology of HFoF1 were elucidated by proteomics, RNA interference, cytoplasts and transgenic mice. The ATP synthesized daily by HFoF1 is in the order of tens of kilograms, and is primarily controlled by the brain in response to fluctuations in activity

Ion temperature clamping in Wendelstein 7-X electron cyclotron heated plasmas

The neoclassical transport optimization of the Wendelstein 7-X stellarator has not resulted in the predicted high energy confinement of gas fueled electron-cyclotron-resonance-heated (ECRH) plasmas as modelled in (Turkin et al 2011 Phys. Plasmas 18 022505) due to high levels of turbulent heat transport observed in the experiments. The electron-turbulent-heat transport appears non-stiff and is of the electron temperature gradient (ETG)/ion temperature gradient (ITG) type (Weir et al 2021 Nucl. Fusion 61 056001). As a result, the electron temperature Te can be varied freely from 1 keV–10 keV within the range of PECRH = 1–7 MW, with electron density ne values from 0.1–1.5 × 1020 m−3. By contrast, in combination with the broad electron-to-ion energy-exchange heating profile in ECRH plasmas, ion-turbulent-heat transport leads to clamping of the central ion temperature at Ti ∼ 1.5 keV ± 0.2 keV. In a dedicated ECRH power scan at a constant density of 〈ne〉 = 7 × 1019 m−3, an apparent \u27negative ion temperature profile stiffness\u27 was found in the central plasma for (r/a < 0.5), in which the normalized gradient ∇Ti/Ti decreases with increasing ion heat flux. The experiment was conducted in helium, which has a higher radiative density limit compared to hydrogen, allowing a broader power scan. This \u27negative stiffness\u27 is due to a strong exacerbation of turbulent transport with an increasing ratio of Te/Ti in this electron-heated plasma. This finding is consistent with electrostatic microinstabilities, such as ITG-driven turbulence. Theoretical calculations made by both linear and nonlinear gyro-kinetic simulations performed by the GENE code in the W7-X three-dimensional geometry show a strong enhancement of turbulence with an increasing ratio of Te/Ti. The exacerbation of turbulence with increasing Te/Ti is also found in tokamaks and inherently enhances ion heat transport in electron-heated plasmas. This finding strongly affects the prospects of future high-performance gas-fueled ECRH scenarios in W7-X and imposes a requirement for turbulence-suppression techniques

Evaluation and validation of radial impurity density profiles from CXRS using neutral beam modelling in W7-X

Absolute radial impurity density profiles in the Wendelstein 7-X stellarator (W7-X) are derived from charge exchange recombination spectroscopy using modelling of the neutral beam. The approach is validated via cross comparisons of the neutral beam attenuation, the radial localization of ion temperature measurements, as well as a comparison of the effective plasma charge determined by other diagnostics. The latter implies the validity of the obtained absolute density levels. The simulation based approach novel to W7-X allows to assess the neutral beam halo population, introducing corrections to the shape and amplitude of determined impurity density profiles. To illustrate the capabilities of the derived impurity density profiles, the particle transport properties in a W7-X discharge heated by electron cyclotron resonance heating were assessed. Density profiles for various impurities are found to be flat, consistent with dominant anomalous diffusion in the range 0.1-5.0 m2 s−1. This range of the anomalous transport in such plasmas is in line with other impurity diagnostics at W7-X.</p