99 research outputs found

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

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    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

    Religion and Attitudes Toward the Environment: A Comparison of Mormons and the General U.S. Population

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    Religion has been shown to influence attitudes toward an array of social issues. This manuscript focuses specifically on environmental issues, with empirical examination of the distinctiveness of contemporary Mormon environmental perspectives as contrasted with the general U.S. population. A belief in the importance of dominion over the environment is noted, by some, to be reflected in anti-environmental stance characterizing Mormon Culture Region political leaders and church members [Foltz, R. C. (2000). Mormon values and the Utah environment. Worldviews: Environment, Culture, Religion, 4, 1–19]. Yet, a set of highly regarded essays by a diverse group of Mormons, including some in church leadership positions, expresses strong personal commitments to environmental causes and point to Mormon teachings and doctrines promoting environmentalism (Williams, Smith, and Gibbs, 1998). We examine variation in environmental concern as expressed by Mormons in a local community survey undertaken in Logan, Utah, as contrasted with the nationally-representative General Social Survey (1993). We find substantial differences between Mormons and the national sample; While Mormons tended to express greater levels of environmental concern, they were less likely to have undertaken specific behaviors reflective of such concern

    On the Upper Bound of a Call Option

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    Using only a weak set of assumptions, Merton (1973) shows that the upper bound of a European or American call option on a non-dividend paying stock is the underlying stock price: a result which is often extended to options on dividend paying stocks. In this short technical piece we show that the underlying stock price is in fact not the least upper bound of either a European or an American call option on a stock that pays one or more known dividends prior to maturity. Based on Merton's (1973) original framework, new upper bounds are established which depend on the size(s) of the dividend(s) compared to the size of the strike. Copyright Springer Science + Business Media, Inc. 2005option, arbitrage, bounds,
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