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

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

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

Are Faces Preferentially Attended when Participants are Unaware of Being Monitored?

Human faces convey a vast amount of information, including but not limited to age, gender, race, emotional state, and attractiveness. The perception of these attributes is important for our social interactions. For this reason, it has been argued that upright faces are a special class of stimuli that are preferentially attended. Preferential processing of fearful or sad expressions in clinical population of anxious individuals or those with severe depression have been reported; however the reports on healthy adult population have not been conclusive and appear to be largely affected by the experimental conditions and response mode. A limitation of laboratory research is that repetitive task performance and behavioural monitoring can restrict the potential impact of biologically-relevant stimuli that would attract attention under more natural conditions. To address this issue, we compare orienting behaviour in two settings: 1) a traditional laboratory task, in which participants make speeded localization responses to face and truck stimuli and 2) stimuli of the same type presented in a waiting area before the experiment began, while participants were unaware that their eye movements were being recorded. In the former setting, participants orientated to faces and trucks similarly (in terms of accuracy and speed); whilst, in the latter setting, participants fixated on faces more frequently, and for greater durations, compared to truck stimuli. These findings indicate that free and unrestricted viewing conditions may be more informative of behaviour than measurements in repeated trials