Alfvén eigenmodes (AEs) excited by fast ions can cause losses of fast ions in thermonuclear experiments. To describe the dynamics of the AE excitation, it is necessary to include the decorrelation of the AE interactions and the renewal of the distribution function in the unstable regions on time scales that are short compared to the decorrelation time. For simulation of AE excitation for finite...

We investigate the launching and stability of extragalactic jets through nonlinear magnetohydrodynamic (MHD) simulation and linear eigenmode analysis. In the simulations of jet evolution, a small-scale equilibrium magnetic arcade is twisted by a differentially rotating accretion disk. These simulations produce a collimated outflow which is unstable to the current driven m = 1 kink mode for low ...

The spatially resolved eigenmode spectrum of micrometer-sized Co ring elements has been determined by means of combined vector network analyzer ferromagnetic resonance and time resolved magneto-optic Kerr effect measurements. Up to 5 resonant eigenmodes were observed in the frequency range from 45 MHz to 20 GHz as a function of an external magnetic bias field. A well-defined mode structure was ...

Eigenmode analysis is a fundamental method to characterize the interaction of beam and accelerator components. Several codes are able to calculate eigenmodes but all of them act on the complete structure which is under consideration. Thus they are restricted to a certain complexity of the resonator depending on the computational capabilities. We present a method that overcomes this restriction ...

Helicon discharges produce plasmas with a density gradient across the confining magnetic field. Such plasmas can create a radial potential well for nonaxisymmetric whistlers, allowing radially localized helicon RLH waves. This work presents new evidence that RLH waves play a significant role in helicon plasma sources. An experimentally measured plasma density profile in an argon helicon dischar...

The main scope of this work is the automation of the extraction procedure of the external quality factors Qext of Higher Order Modes (HOMs) in Superconducting (SC) radio frequency (RF) cavities. The HOMs are generated by charged particle beams traveling through a SC cavity at the speed of light (β ≈ 1). The HOMs decay very slowly, depending on localization inside the structure and cell-to-cell ...

-&-Fast wave heating at the second, third and fourth harmonics of the ion cyclotron resonance, and slow wave heating at the fundamental in a single ion species hydrogen plasma, are found to be in gQod agreement with warm plasma theory at rf power levels 5130 kW. Ion heating is negligible off an eigenmode. Ion body temperatures are more than doubled to 75 eV from the 35 eV ohmically heated case ...

We experimentally demonstrate the feasibility of a super-resolution technique based on eigenmode decomposition. This technique has been proposed theoretically but, to the best of our knowledge, has not previously been realized experimentally for optical imaging systems with circular apertures. We use a standard diffraction-limited 4f imaging system with circular apertures for which the radial e...