Analysis of the C2_2 (d3Πg^3\Pi_g-a3Πu^3\Pi_u) Swan bands as a thermometric probe in CO2_2 microwave plasmas

The optical emission spectra of high pressure CO$_2$ microwave plasmas are usually dominated by the C$_2$ Swan bands. In this paper, the use of the C$_2$ Swan bands for estimating the gas temperature in CO$_2$ microwave plasmas is assessed. State by state fitting is employed to check the correctness of assuming a Boltzmann distribution for the rotational and vibrational distribution functions and, within statistical and systematic uncertainties, the C$_2$ Swan band can be fitted accurately with a single temperature for rotational and vibrational levels. The processes leading to the production of the C$_2$ molecule and particularly its d$^3\Pi_g$ state are briefly reviewed as well as collisional relaxation times of the latter. It is concluded that its rotational temperature can be associated to the gas temperature of the CO$_2$ microwave plasma and the results are moreover cross-checked by adding a small amount of N$_2$ in the discharge and measuring the CN violet band system. The 2.45~GHz plasma source is analyzed in the pressure range 180-925~mbar, for input microwave powers ranging from 0.9 - 3 kW and with gas flow rates of 5-100~L/min. An intense C$_2$ Swan bands emission spectrum can be measured only when the plasma is operated in contracted regime. A unique temperature of about 6000 $\pm$ 500 K is obtained for all investigated conditions. A spectroscopic database is constructed using the recent compilation and calculations by Brooke et al. \cite{BROOKE201311} of the line strengths and molecular constants for the C$_2$ (d$^3\Pi_g$-a$^3\Pi_u$) Swan bands system and made available as Supplementary Material in a format compatible with the open source MassiveOES software

Relationships between sex role, empathy and anxiety

Recently Sandra Bem, a psychologist at Stanford University has written about the importance of developing a conception of mental health which is free from culturally imposed definitions of masculinity and femininity. She believes that defining certain behaviors as appropriate only for women and other behaviors as only appropriate for men is restricting and debilitating for both sexes. This sex-typing of behaviors has led to masculinity being associated with assertiveness and dominance, pragmatism, problem solving and task orientation, and a concern for one\u27s individuality, whereas femininity is associated with emotional sensitivity and concern for the welfare of others, the seeking of harmony between oneself and others, and passivity. This study looks at the relationships between masculinity, femininity, anxiety and empathy. Specifically of concern is whether “Androgyny”, a new sex role, seems to be less debilitating and restricting than the traditional “Masculine” and “Feminine” roles as measured by anxiety and empathy scores. The sex role categories of Bem which are used in this study are derived from the Bem Sex Role Inventory. The categories are: 1) “Masculine referring to someone scoring high in masculinity and low in femininity, 2) “Feminine” referring to someone scoring high in femininity and low in masculinity, 3) “Androgynous” referring to someone scoring high in both masculinity and femininity, and 4) “Undifferentiated” referring to someone scoring low in both masculinity and femininity. All the masculine-feminine (M-F) scales referred to in the following studies give measures corresponding to Bem\u27s categories of “Feminine” and “Masculine”. In traditional M-F scales scoring high in femininity is equivalent to a “Feminine” sex role and scoring high in masculinity is equivalent to a Masculine sex role. The reason for this is that traditional M-F scales are structured so that masculinity and femininity are opposite poles on the same dimension and therefore as one moves toward greater femininity one also moves away from masculinity and vice versa. Bem’s inventory, however, is constructed so that masculinity and femininity are orthogonal dimensions. This allows for the development of two other possible sex roles: “Androgynous” and “Undifferentiated”. No predictions will be made about the latter category

Penta-hepta defect chaos in a model for rotating hexagonal convection

In a model for rotating non-Boussinesq convection with mean flow we identify a regime of spatio-temporal chaos that is based on a hexagonal planform and is sustained by the {\it induced nucleation} of dislocations by penta-hepta defects. The probability distribution function for the number of defects deviates substantially from the usually observed Poisson-type distribution. It implies strong correlations between the defects inthe form of density-dependent creation and annihilation rates of defects. We extract these rates from the distribution function and also directly from the defect dynamics.Comment: 4 pages, 5 figures, submitted to PR

Negative Ion Source Development for Fusion Application (invited)

Giant negative ion sources, producing high-current of several tens amps with high energy of several hundreds keV to 1 MeV, are required for a neutral beam injector(NBI) in a fusion device. The giant negative ion sources are cesium-seeded plasma sources, in which the negative ions are produced onthe cesium-covered surface. Their characteristic features are discussed with the views of large-volume plasma production, large-area beam acceleration, and high-voltage dc holding. The international thermonuclear experimental reactor NBI employs a 1 MeV-40 A of deuterium negativeion source, and intensive development programs for the rf-driven source plasma production and the multistage electrostatic acceleration are in progress, including the long pulse operation for 3600 s. Present status of the development, as well as the achievements of the giant negative ion sources in the working injectors, is also summarized

Beamlet scraping and its influence on the beam divergence at the BATMAN Upgrade test facility

For the ITER fusion experiment, two neutral beam injectors are required for plasma heating and current drive. Each injector supplies a power of about 17 MW, obtained from neutralization of 40 A (46 A), 1 MeV (0.87 MeV) negative deuterium (hydrogen) ions. The full beam is composed of 1280 beamlets, formed in 16 beamlet groups, and strict requirements apply to the beamlet core divergence (<7 mrad). The test facility BATMAN Upgrade uses an ITER-like grid with one beamlet group, which consists of 70 apertures. In a joint campaign performed by IPP and Consorzio RFX to better assess the beam optics, the divergence of a single beamlet was compared to a group of beamlets at BATMAN Upgrade. The single beamlet is measured with a carbon fiber composite tile calorimeter and by beam emission spectroscopy, whereas the divergence of the group of beamlets is measured by beam emission spectroscopy only. When increasing the RF power at low extraction voltages, the divergence of the beamlet and of the group of beamlets is continuously decreasing and no inflection point toward an overperveant beam is found. At the same time, scraping of the extracted ion beam at the second grid (extraction grid) takes place at higher RF power, supported by the absence of the normally seen linear behavior between the measured negative ion density in the plasma close to the extraction system and the measured extracted ion current. Beside its influence on the divergence, beamlet scraping needs to be considered for the determination of the correct perveance and contributes to the measured coextracted electron current

Rotating Convection in an Anisotropic System

We study the stability of patterns arising in rotating convection in weakly anisotropic systems using a modified Swift-Hohenberg equation. The anisotropy, either an endogenous characteristic of the system or induced by external forcing, can stabilize periodic rolls in the K\"uppers-Lortz chaotic regime. For the particular case of rotating convection with time-modulated rotation where recently, in experiment, chiral patterns have been observed in otherwise K\"uppers-Lortz-unstable regimes, we show how the underlying base-flow breaks the isotropy, thereby affecting the linear growth-rate of convection rolls in such a way as to stabilize spirals and targets. Throughout we compare analytical results to numerical simulations of the Swift-Hohenberg equation

Stability of Oscillating Hexagons in Rotating Convection

Breaking the chiral symmetry, rotation induces a secondary Hopf bifurcation in weakly nonlinear hexagon patterns which gives rise to oscillating hexagons. We study the stability of the oscillating hexagons using three coupled Ginzburg-Landau equations. Close to the bifurcation point we derive reduced equations for the amplitude of the oscillation, coupled to the phase of the underlying hexagons. Within these equation we identify two types of long-wave instabilities and study the ensuing dynamics using numerical simulations of the three coupled Ginzburg-Landau equations.Comment: 25 pages, 7 figure

Seeing two faces together: preference formation in humans and rhesus macaques

Humans, great apes and old world monkeys show selective attention to faces depending on conspecificity, familiarity, and social status supporting the view that primates share similar face processing mechanisms. Although many studies have been done on face scanning strategy in monkeys and humans, the mechanisms influencing viewing preference have received little attention. To determine how face categories influence viewing preference in humans and rhesus macaques (Macaca mulatta), we performed two eye-tracking experiments using a visual preference task whereby pairs of faces from different species were presented simultaneously. The results indicated that viewing time was significantly influenced by the pairing of the face categories. Humans showed a strong bias towards an own-race face in an Asian–Caucasian condition. Rhesus macaques directed more attention towards non-human primate faces when they were paired with human faces, regardless of the species. When rhesus faces were paired with faces from Barbary macaques (Macaca sylvanus) or chimpanzees (Pan troglodytes), the novel species’ faces attracted more attention. These results indicate that monkeys’ viewing preferences, as assessed by a visual preference task, are modulated by several factors, species and dominance being the most influential

Instabilities of Hexagonal Patterns with Broken Chiral Symmetry

Three coupled Ginzburg-Landau equations for hexagonal patterns with broken chiral symmetry are investigated. They are relevant for the dynamics close to onset of rotating non-Boussinesq or surface-tension-driven convection. Steady and oscillatory, long- and short-wave instabilities of the hexagons are found. For the long-wave behavior coupled phase equations are derived. Numerical simulations of the Ginzburg-Landau equations indicate bistability between spatio-temporally chaotic patterns and stable steady hexagons. The chaotic state can, however, not be described properly with the Ginzburg-Landau equations.Comment: 11 pages, 7 figures, submitted to Physica