Lifeboat Foundation

We use the new simulation capabilities of the extended-magnetohydrodynamic (MHD) code, M3D-C1, to investigate the nonlinear MHD properties of a reactor-scale quasisymmetric stellarator equilibrium. Our model captures the self-consistent evolution of the magnetic field, temperature, density, and flow profiles without imposing restrictions on the structure of the first. We include the effects of resistivity using a realistic temperature-dependent Spitzer model, along with a model for heat transport that captures the key physical characteristic, namely, strongly anisotropic diffusion in directions perpendicular and parallel to the magnetic field. We consider a quasi-axisymmetric, finite-pressure equilibrium that was optimized for self-consistent bootstrap current, quasi-symmetry, and energetic particle confinement. Our assessment finds that the equilibrium is highly unstable to interchange-like pressure-driven instabilities near the plasma edge. The initially unstable modes rapidly destabilize other modes in the direction of the N-fold rotational symmetry (toroidal, in this case). For this equilibrium, N = 2, meaning destabilization of a large number of even-numbered toroidal Fourier modes. Thus, field-periodicity is likely to be an important factor in the nonlinear MHD stability characteristics of optimized stellarators.

Researchers have linked supermassive black hole mergers with dark matter interactions, potentially solving a longstanding astronomical problem and offering new insights into dark matter’s nature and its role in the cosmos.

Researchers have found a link between some of the largest and smallest objects in the cosmos: supermassive black holes and dark matter particles.

Continue reading “Dark Matter Was the Key: Astrophysicists Solve Longstanding ‘Final Parsec Problem’” »

The tin-vacancy center in diamond has properties that could be useful for quantum networks.

In a new study, researchers show how this defect’s electron spin can be controlled — and coherence prolonged — using a superconducting microwave waveguide.

Even the most pristine diamonds can host defects arising from missing atoms (vacancies) or naturally occurring impurities. These defects possess atomlike properties such as charge and spin, which can be accessed optically or magnetically. Over the past few decades, researchers have studied various defects to understand and harness these properties. One in particular—the tin-vacancy center, in which a tin atom resides on an interstitial site with two neighboring vacancies—exhibits exceptionally useful optical and spin properties, making it highly relevant in the field of quantum communication. Here, we explore how the spin properties behave under different magnetic field directions.

Continue reading “Microwave Control of the Tin-Vacancy Spin Qubit in Diamond with a Superconducting Waveguide” »

A team led by Stevens professor Igor Pikovski has just outlined how to detect single gravitons, thought to be the quantum building blocks of gravity—and making that experiment real should be possible with quantum technology, they suggest, in the near future.

In recent years, advances in photonics and materials science have led to remarkable developments in sensor technology, pushing the boundaries of what can be detected and measured. Among these innovations, non-Hermitian physics has emerged as a crucial area of research, offering new ways to manipulate light and enhance sensor sensitivity.

J.J. Thomson won the Nobel Prize in physics in 1906 showing that the electron is a particle: ironically, his son, G.P. Thomson, won the Nobel Prize in physics in 1937 showing that it is not (or rather that the electron can also behave as a wave)

A tale of two Thomsons.

Simulating particles is a relatively simple task when those particles are spherical. In the real world, however, most particles are not perfect spheres, but take on irregular and varying shapes and sizes. Simulating these particles becomes a much more challenging and time-consuming task.

Nothing in science can be achieved or understood without measurement. Today, thanks to advances in quantum sensing, scientists can measure things that were once impossible to even imagine: vibrations of atoms, properties of individual photons, fluctuations associated with gravitational waves.

A groundbreaking study explores anomalies in particle physics experiments, suggesting the existence of new bosons.