139 research outputs found

    Who reports absence of sexual attraction in Britain? Evidence from national probability surveys

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    There is little evidence about the prevalence of absence of sexual attraction, or the characteristics of people reporting this, often labelled asexuals. We examine this using data from two probability surveys of the British general population, conducted in 1990–1991 and 2000–2001. Interviewers administered face-to-face and self-completion questionnaires to people aged 16–44 years (N = 13,765 in 1990–1991; N = 12,110 in 2000–2001). The proportion that had never experienced sexual attraction was 0.4% (95% CI: 0.3–0.5%) in 2000–2001, with no significant variation by gender or age, versus 0.9% (95% CI: 0.7–1.1%) in 1990–1991; p < 0.0001. Among these 79 respondents in 2000–2001, 28 (40.3% men; 33.9% women) had had sex, 19 (33.5% men; 20.9% women) had child(ren), and 17 (30.1% men; 19.2% women) were married. Three-quarters of asexual men and two-thirds of asexual women considered their frequency of sex ‘about right’, while 24.7% and 19.4%, respectively, ‘always enjoyed having sex’. As well as providing evidence on the distribution of asexuality in Britain, our data suggest that it cannot be assumed that those reporting no sexual attraction are sexually inexperienced or without intimate relationships. We recognise the possibility of social desirability bias given our reliance on self-reported data, but suggest that its effect is not easily predicted regarding absence of sexual attraction

    Exploration of the equilibrium operating space for NSTX-Upgrade

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    This paper explores a range of high-performance equilibrium scenarios available in the NSTX-Upgrade device [J.E. Menard, submitted for publication to Nuclear Fusion]. NSTX-Upgrade is a substantial upgrade to the existing NSTX device [M. Ono, et al., Nuclear Fusion 40, 557 (2000)], with significantly higher toroidal field and solenoid capabilities, and three additional neutral beam sources with significantly larger current drive efficiency. Equilibria are computed with freeboundary TRANSP, allowing a self consistent calculation of the non-inductive current drive sources, the plasma equilibrium, and poloidal field coil current, using the realistic device geometry. The thermal profiles are taken from a variety of existing NSTX discharges, and different assumptions for the thermal confinement scalings are utilized. The no-wall and idealwall n=1 stability limits are computed with the DCON code. The central and minimum safety factors are quite sensitive to many parameters: they generally increases with large outer plasmawall gaps and higher density, but can have either trend with the confinement enhancement factor. In scenarios with strong central beam current drive, the inclusion of non-classical fast ion diffusion raises qmin, decreases the pressure peaking, and generally improves the global stability, at the expense of a reduction in the non-inductive current drive fraction; cases with less beam current drive are largely insensitive to additional fast ion diffusion. The non-inductive current level is quite sensitive to the underlying confinement and profile assumptions. For instance, for BT=1.0 T and Pinj=12.6 MW, the non-inductive current level varies from 875 kA with ITER-98y,2 thermal confinement scaling and narrow thermal profiles to 1325 kA for an ST specific scaling expression and broad profiles. This sensitivity should facilitate the determination of the correct scaling of transport with current and field to use for future fully non-inductive ST devices. Scenarios are presented which can be sustained for 8-10 seconds, or (20-30)τCR, at ÎČN=3.8-4.5, facilitating, for instance, the study of disruption avoidance for very long pulse. Scenarios have been documented which can operate with ÎČT~25% and equilibrated qmin&gt;1. The value of qmin can be controlled at either fixed non-inductive fraction of 100% or fixed plasma current, by varying which beam sources are used, opening the possibility for feedback qmin control. In terms of quantities like collisionality, neutron emission, non-inductive fraction, or stored energy, these scenarios represent a significant performance extension compared to NSTX and other present spherical torii

    Measurement of the gamma ray background in the Davis Cavern at the Sanford Underground Research Facility

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    Deep underground environments are ideal for low background searches due to the attenuation of cosmic rays by passage through the earth. However, they are affected by backgrounds from Îł-rays emitted by 40K and the 238U and 232Th decay chains in the surrounding rock. The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a liquid xenon TPC located within the Davis campus at the Sanford Underground Research Facility, Lead, South Dakota, at the 4,850-foot level. In order to characterise the cavern background, in-situ Îł-ray measurements were taken with a sodium iodide detector in various locations and with lead shielding. The integral count rates (0--3300~keV) varied from 596~Hz to 1355~Hz for unshielded measurements, corresponding to a total flux in the cavern of 1.9±0.4~Îł cm−2s−1. The resulting activity in the walls of the cavern can be characterised as 220±60~Bq/kg of 40K, 29±15~Bq/kg of 238U, and 13±3~Bq/kg of 232Th
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