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

Population Genetic Structure of Brook Trout in the Loyalsock Creek Watershed

The rarity and magnitude of large disturbance events produce unpredictable changes to aquatic ecosystems. In particular, high stream flows can result in an immediate loss of fish populations and reduce genetic diversity through bottleneck effects. Conversely, high stream flows may increase population viability by facilitating movement of individuals among populations and by increasing habitat heterogeneity. In 2011, a 500-year flood event occurred in Loyalsock Creek causing catastrophic loss of many fish populations. Populations have since recovered, with some exceeding pre-flood size. However, the genetic structure of recovered populations is uncertain. As such, it is unknown whether the flood increased genetic connectivity by temporarily increasing population connectivity, or has induced loss of genetic diversity through founder effects. In summer 2015, we sampled 27 tributaries of the Loyalsock Creek to determine the genetic structure of adult brook trout (Salvelinus fontinalis) populations. Results will help inform management of brook trout populations in Loyalsock Creek and future studies concerning the behavior and movement of brook trout related to climate change and spawning habitat use

Biodegradation of Prions in Compost

Composting may serve as a practical and economical means of disposing of specified risk materials (SRM) or animal mortalities potentially infected with prion diseases (transmissible spongiform encephalopathies, TSE). Our study investigated the degradation of prions associated with scrapie (PrP^263K), chronic waste disease (PrP^CWD), and bovine spongiform encephalopathy (PrP^BSE) in lab-scale composters and PrP^263K in field-scale compost piles. Western blotting (WB) indicated that PrP^263K, PrP^CWD, and PrP^BSE were reduced by at least 2 log₁₀, 1–2 log₁₀, and 1 log₁₀ after 28 days of lab-scale composting, respectively. Further analysis using protein misfolding cyclic amplification (PMCA) confirmed a reduction of 2 log₁₀ in PrP^263K and 3 log₁₀ in PrP^CWD. Enrichment for proteolytic microorganisms through the addition of feather keratin to compost enhanced degradation of PrP^263K and PrP^CWD. For field-scale composting, stainless steel beads coated with PrP^263K were exposed to compost conditions and removed periodically for bioassays in Syrian hamsters. After 230 days of composting, only one in five hamsters succumbed to TSE disease, suggesting at least a 4.8 log₁₀ reduction in PrP^263K infectivity. Our findings show that composting reduces PrP^TSE, resulting in one 50% infectious dose (ID₅₀) remaining in every 5600 kg of final compost for land application. With these considerations, composting may be a viable method for SRM disposal