相关论文: Evolution of safety factor profiles in sawteeth
We present a sawtooth model that explains observations where the central safety factor, $q_0$, stays well below one, which is irreconcilable with current models that predict a reset to $q_0=1$ after the crash. We identify the structure of…
We discuss the role of neoclassical resistivity and local magnetic shear in the triggering of the sawtooth in tokamaks. When collisional detrapping of electrons is considered the value of the safety factor on axis, $q(0,t)$, evolves on a…
We theoretically explore the possibility of sausage instabilities developing on top of a kink instability in lengthening current-carrying magnetic flux tubes. Observations indicate that the dynamics of magnetic flux tubes in our cosmos and…
In this work we consider magnetic reconnection in thin current sheets with both resistive and electron inertia effects. When the current sheet is produced by a primary instability of the internal kink type, the analysis of secondary…
A model for incomplete reconnection in sawtooth crashes is presented. The reconnection inflow during the crash phase of sawteeth self-consistently convects the high pressure core toward the reconnection site, raising the pressure gradient…
A relaxed baseline case, based on the SPARC Primary Reference Discharge (PRD) design point, is used to conduct a thorough investigation for the most unstable low-$n$ MHD instabilities for the first time. The simulations use the…
The value of the safety factor on the magnetic axis of a finite-beta spheromak is shown to be a function of beta in contrast to what was used in P. M. Bellan, Phys. Plasmas 9, 3050 (2002); this dependence on beta substantially reduces the…
Usually, the degree of stability of a slope is quantified by the Factor of Safety whose values depend on physical and mechanical soil properties analyzed on samples of much reduced sizes or referring to very small soil volumes around porous…
We have measured magnetic torque on a $T_N=7$ K single crystal of $\alpha$-RuCl$_3$, as a function of the field angle in the $ab$-plane, focusing on temperatures between 2 and 20 K and fields from 0 to 9 T. We find a number of features,…
It is shown that considering a fixed increment of a given magnitude at a fault is equivalent to factoring the mechanical moment at the fault as done in structural engineering with the applied loads, by the most currently used structural…
To systematically stress a rotationally symmetric 3D magnetic null point by advecting the opposite footpoints of the spine axis in opposite directions. This stress eventually concentrates in the vicinity of the null point forming a local…
We have performed 2.5D and 3D simulations of conical jets driven by the rotation of an ordered, large-scale magnetic field in a stratified atmosphere. The simulations cover about three orders of magnitude in distance to capture the…
Stability properties of ``magnetic tower'' jets propagating in the gravitationally stratified background have been examined by performing three-dimensional magnetohydrodynamic simulations. The current-carrying, Poynting flux-dominated…
A new criterion for pressure-driven interchange instabilities in cylindrical geometry is derived, based on an alternate use of the Energy Principle. This criterion is inequivalent to Suydam's criterion and does not contain the magnetic…
Inelastic neutron scattering measurements have been performed on a superconducting single crystal FeTe$_{0.5}$Se$_{0.5}$ to examine the ${\bf Q}$-dependent enhancement of the dynamical structure factor, $S({\bf Q},E)$, from ${\bf Q}$ = (0,…
Sweet-Parker current sheets in high Lundquist number plasmas are unstable to tearing, suggesting they will not form in physical systems. Understanding magnetic reconnection thus requires study of the stability of a current sheet as it…
Due to the conformal factor problem, the definition of the Euclidean gravitational path integral requires a non-trivial choice of contour. The present work examines a generalization of a recently proposed rule-of-thumb \cite{Marolf:2022ntb}…
Context: The expansion of network magnetic fields with height is a fundamental property of flux tube models. A rapid expansion is required to form a magnetic canopy. Aims: We characterize the observed expansion properties of magnetic…
In our prior papers, we considered the non-relativistic linear stability analysis of magnetized jets that do not have current sheet at the boundary. In this paper, we extend our analysis to relativistic jets. In order to find the unstable…
We discuss general momentum-dependent field redefinitions in the context of quantum-gravitational scattering amplitudes in general, and Asymptotic Safety in particular. Implementing such redefinitions at the lowest curvature order, we can…