Continuous Signal-Based Neutron Noise Measurements Demonstrated as Viable Alternative to Pulse-Counting
Researchers have demonstrated the feasibility of analyzing continuous detector current signals to measure neutron noise in nuclear reactors, overcoming limitations of traditional pulse-counting methods at high detection rates. The method uses stochastic modeling and signal processing techniques like deconvolution to account for pulse-shape distortions and dead-time effects. This advancement could improve the accuracy of kinetic parameter measurements in reactor diagnostics, particularly in high-rate operational conditions.
A new study published on arXiv presents experimental and simulation-based evidence that continuous-signal neutron noise analysis can reliably determine reactor kinetic parameters such as the prompt neutron decay constant. Traditional pulse-counting methods become unreliable at high detection rates due to dead-time losses and pile-up effects, but analyzing the continuous detector current can circumvent these limitations if pulse-shape distortions are properly corrected. The researchers applied stochastic detector current modeling to derive Rossi- and Feynman-type formulations and tested two mitigation approaches: using detector pairs or applying inverse Fourier and Wiener filtering for deconvolution. Simulations showed accurate alpha-parameter estimation at count rates where conventional methods fail, while experiments conducted at KUCA and BME TR research reactors confirmed that both continuous and deconvolved signals yield unbiased results despite dead-time and electronic artifacts. The work establishes continuous-signal analysis as a practical alternative for high-rate reactor noise diagnostics.
What different sources said
- arXiv physicsCenter
Feasibility demonstration of continuous signal-based neutron noise measurements by experiments and simulations
Related
Gut Bacteria Enzyme Found to Break Down Heat-Processed Food Compounds, Producing Novel Biogenic Amines
Researchers have discovered that an enzyme in common gut bacteria can degrade N-epsilon-carboxymethyllysine (CML), a compound formed during thermal food processing, producing previously unknown biogenic amines. The enzyme, ornithine decarboxylase SpeC from enterobacteria, acts on CML and related modified lysine derivatives through a low-level 'underground' catalytic activity. This finding suggests a previously unrecognized communication axis between thermally processed dietary compounds and gut microbial physiology, with potential implications for host health.
Full-Length Gene Sequencing Reveals Two Distinct Bacterial Communities in Black-Legged Ticks Expanding Into Canada
Researchers used Oxford Nanopore full-length 16S rRNA gene sequencing to characterize the microbiome of Ixodes scapularis black-legged ticks collected in Nova Scotia, Canada, distinguishing between tick-adapted bacteria and environmentally acquired bacteria. The study comes as I. scapularis — the primary vector of Lyme disease — is rapidly expanding northward into Canada due to climate change. The findings suggest that environmentally derived bacteria in tick microbiomes are not mere contamination, which has implications for how tick microbiome data is collected and interpreted across surveillance studies.
Study Identifies Metabolic Link Between Cell Envelope Stress and Biofilm Formation in Bacteria
Researchers have discovered that the metabolite acetyl-CoA directly inhibits enzymes that degrade the bacterial signaling molecule c-di-GMP, connecting cell envelope biosynthesis stress to biofilm formation in Pseudomonas aeruginosa. The study found that sub-inhibitory concentrations of antibiotics targeting early peptidoglycan biosynthesis — but not other antibiotic classes — elevate c-di-GMP levels by reducing phosphodiesterase activity, with acetyl-CoA competing for the enzyme active site. Because the relevant enzyme domain is broadly conserved across bacterial species, this checkpoint mechanism may be widespread and could have implications for understanding antibiotic-induced biofilm responses.