The SPARC tokamak project, currently in engineering design, aims to achieve breakeven and burning plasma conditions in a compact device, thanks to new developments in high-temperature superconductor technology. With a magnetic field of 12.2 T on axis and 8.7 MA of plasma current, SPARC is predicted to produce 140 MW of fusion power with a plasma gain of Q ≈ 11, providing ample margin with respect to its mission of Q > 2. All tokamak systems are being designed to produce this landmark plasma discharge, thus enabling the study of burning plasma physics and tokamak operations in reactor relevant conditions to pave the way for the design and construction of a compact, high-field fusion power plant. Construction of SPARC is planned to begin by mid-2021.

Helium bubbles in metals spontaneously form networks of interconnected channels.

We describe a transmission electron microscopy investigation of the distribution of helium precipitates within the plane of an interface between Cu and V. Statistical analysis of precipitate locations reveals a weak tendency for interfacial precipitates to align along 110 -type crystallographic directions within the Cu layer. Comparison of these findings with helium-free Cu/V interfaces suggests that the precipitates may be aggregating preferentially along atomic-size steps in the interface created by threading dislocations in the Cu layer. Our observations also suggest that some precipitates may be aggregating along intersections between interfacial misfit dislocations. IMPACT STATEMENTThe innovation of this paper is providing the first plane-view experimental images of in-plane helium precipitate distributions at an interface between physical vapor deposited face-centered cubic (fcc) and body-centered cubic (bcc) metals. ARTICLE HISTORY

Formation of silver nanoparticles under anodic surface of tellurite glass via thermal poling-assisted ion implantation across solid-solid interface Low temperature metal induced crystallization of amorphous silicon using a Ni solution

We develop a phase field simulation to model morphology evolution of helium (He) precipitates on solid-state interfaces. Our approach accounts for differences in precipitate contact angles arising from location-dependent interface energies and is capable of describing precipitate growth, coalescence, and de-wetting from the interface. We demonstrate our approach for interfaces with linear chains of wettable patches and find that different wetting energies and patch spacings give rise to four distinct classes of helium precipitate morphologies. Our method may be adapted to other scenarios involving fluids precipitating on non-uniform solid-state interfaces as well as to precipitation on patterned surfaces.