Abstract

A simple impurity model has been developed under the BOUT++ framework to investigate the Li-pellet triggered edge localized mode (ELM) in EAST configuration. The present impurity model decouples the ion pressure enhancement effect (IPEE) (which affects radial E$ \times $B flow shear and gyro-viscosity of deuterium ions and is implicitly included in our previous work) to make the simulation of Li pellet injection more physically reasonable. In addition, the present impurity model also includes the impurity equilibrium effect (IEE) (which induces modifications on vorticity and gyro-viscosity). The simulation results show that without IPEE a turbulent ELM induced by Li pellet is triggered by multiple peeling-ballooning modes (PBMs) rather than by a single dominant mode, and the simultaneous growth of multiple modes is conducive to reducing the time for pedestal entering the energy loss state. When a turbulent ELM occurs, the nonlinearly dominant modes undergo a secondary fast growth during fast crash phase. The finding explains the secondary increase of $ D_{\alpha } $ emission observed in the DIII-D Li injection experiments. During the evolution of a turbulent ELM, the continuous pedestal collapse dominates the pedestal energy loss in turbulent transport phase; however, in saturation phase, the stabilizing effects on PBMs (n$ \neq $ 0) by n = 0 mode and radial E$ \times $B flow shear within the steepest gradient region are more prominent. It is also found that with IEE and without IPEE, the size threshold of ELM triggering and the magnitude of ELM sizes both show a good agreement with EAST and DIII-D experimental observations.

• Book : 65(2)
• Pub. Date : 2025
• Page : pp.026007
• Keyword :

• Book : 1010()
• Pub. Date : 2025
• Page : pp.116774
• Keyword :

• Book : 213()
• Pub. Date : 2025
• Page : pp.111123
• Keyword :

Summary

Temperatures perceived early in the life cycle of mother plants can affect the germination of the offspring seeds. In Arabidopsis thaliana, vernalisation‐insensitive mutants showed altered germination response to elevated maternal temperature, hence revealing a strong genetic determinism. However, the genetic control of this maternal effect and its prevalence across natural populations remain unclear.

Here, we exposed a collection of European accessions of A. thaliana to increased temperature during the vegetative phase and assessed germination in their progeny to identify the genetic basis of transgenerational germination response. We found that genotypes with rapidly germinating progeny after early maternal exposure to elevated temperature originated from regions with low‐light radiation.

Combining genome‐wide association, expression analysis and functional assays across multiple genetic backgrounds, we show a central role for PHYB in mediating the response to maternally perceived temperature at the vegetative stage. Differential gene expression analysis in leaves identified a similar genetic network as previously found in seed endosperm under elevated temperature, supporting the pleiotropic involvement of PHYB signalling across different tissues and stages.

This provides evidence that complex environmental responses modulated by the maternal genotype can rely on a consistent set of genes yet produce different effects at the different stages of exposure.

• Book : 245(2)
• Pub. Date : 2025
• Page : pp.668-683
• Keyword :

Abstract

Deuterium gas-puff z-pinches are researched primarily as efficient sources of DD fusion neutrons. The first experiment with a deuterium gas jet was carried out in 1978 (Shiloh et al 1978 Phys. Rev. Lett.40 515518). Since then, several D2 gas-puff experiments have been performed on various pulsed-power generators. The highest, so far published, DD neutron yields of $ 4 \times 10^{ 13 } $ were observed on the Z machine at Sandia National Laboratories around 2005 (Coverdale et al 2007 Phys. Plasmas14 022706). More recently, z-pinch experiments with a plasma-shell on a deuterium gas puff were carried out on the GIT-12 higher-impedance pulsed-power generator at 3 MA currents. On GIT-12, unique results were high neutron and ion energies, which approached 60 MeV. Comparison of deuterium gas-puff experiments on different generators allows the identification of the parameters essential for optimizing neutron production. These parameters include the optimal mass, preionization, short deuterium gas-injection time, and zippering towards a cathode. Neutron yields appear to depend not only on a current, but also on other parameters of a generator, such as an impedance and the energy stored in a capacitor bank. Our conclusions regarding the optimal conditions were tested on the Hawk generator (NRL, Washington, DC). At a current of 0.7 MA, Hawk accelerated deuterons up to 15 MeV producing one neutron pulse with the yield of the order of 10¹⁰ and a broad energy spectrum in the axial and radial direction. These results show that ion acceleration mechanisms in deuterium gas-puff z-pinches could be very efficient and attractive, with a variety of potential applications in high-energy-density physics, materials science, and controlled thermonuclear fusion research.

• Book : 65(2)
• Pub. Date : 2025
• Page : pp.026014
• Keyword :

• Book : 89(1)
• Pub. Date : 2025
• Page : pp.87-92
• Keyword :

Abstract

Objective: Nuclear fragmentation generates a diverse dosimetric environment in the path of ¹²C ion beams. Concise parametrization of the beam’s composition is paramount for determining key correction factors in clinical dosimetry. This study sets out to provide such a parametrization based on detailed Monte Carlo simulations of clinically relevant ¹²C beams. Special attention was paid to the products of nuclear fragmentations and their importance in determining the stopping power ratios. Approach: Using the Monte Carlo simulation package GATE, the spectral fluence of all primary and secondary particles in water were computed at different depths for selected clinically relevant incident energies. Collision-stopping power data was taken from the ICRU90, SRIM and MSTAR database, as well as from previous publications. Main results: The choice of stopping power data was shown to have a bigger impact on the resulting stopping power ratio than the choice of physics lists for the simulations. Significance: A comprehensive analysis of the relationship between fragmentation and dosimetric data has been provided. This study compared different methods for determining spectral fluence-based stopping power ratios, which is essential for accurate ion beam dosimetry.

• Book : 70(1)
• Pub. Date : 2025
• Page : pp.015007
• Keyword :

A critical unanswered question is what is causing the increase in the prevalence of autoimmunity and autoimmune diseases around the world. Given the rapidity of change, this is likely the result of major recent alterations in our exposures to environmental risk factors for these diseases. More evidence is becoming available that the evolution of autoimmune disease, years or even decades in the making, results from multiple exposures that alter susceptible genomes and immune systems over time. Exposures during sensitive phases in key developmental or hormonal periods may set the stage for the effects of later exposures. It is likely that synergistic and additive impacts of exposure mixtures result in chronic low‐level inflammation. This inflammation may eventually pass thresholds that lead to immune system activation and autoimmunity, and with further molecular and pathologic changes, the complete clinical syndrome emerges. Much work remains to be done to define the mechanisms and risk and protective factors for autoimmune conditions. However, evidence points to a variety of pollutants, xenobiotics, infections, occupational exposures, medications, smoking, psychosocial stressors, changes in diet, obesity, exercise, and sleep patterns, as well as climate change impacts of increased heat, storms, floods, wildfires, droughts, UV radiation, malnutrition, and changing infections, as possible contributors. Substantial investments in defining the role of causal factors, in whom and when their effects are most important, the necessary and sufficient gene‐environment interactions, improved diagnostics and therapies, and preventive strategies are needed now to limit the many negative personal, societal, and financial impacts that will otherwise occur.

• Book : 77(1)
• Pub. Date : 2025
• Page : pp.3-11
• Keyword :

• Book : 35(5)
• Pub. Date : 2025
• Page : pp.1-5
• Keyword :

Abstract

A case for compact gross electricity producing pilot plant is presented. The feasibility of such a plant with a moderate fusion power that is capable of delivering gross electricity to the grid is investigated. The physics and engineering considerations of such power plants are elucidated. We show that for a fusion power of about 300 MW with fusion gain of 5, a moderate plasma β with improved confinement regime is required to prevent excessive transport power loss. The sensitivity analysis indicates a wide enough parameter range where, the fusion power and fusion gain can meet their target values. The constraints arising from the shielding, magnets and maintenance are discussed. The feasibility of steady-state gross electricity production of 160 MW is discussed using a helium-cooled solid breeder blanket with an intermediate energy storage system. It is argued that such a plant has all key technical elements of DEMO, albeit at a smaller scale, thereby providing strong technical basis for DEMO.

• Book : 65(1)
• Pub. Date : 2025
• Page : pp.016058
• Keyword :