Microwave single bunch instability in circular accelerators has been observed in many machines. The instability usually arises when the number of particles in the bunch exceeds some critical value, Nc, which varies depending on the parameters of the accelerating regime. Recent observations on the SLC damping rings at SLAC [1] with a new low-impedance vacuum chamber revealed new interesting feat...

Energy dynamics calculations in a 3D fluid simulation of drift wave turbulence in the linear Large Plasma Device [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] illuminate processes that drive and dissipate the turbulence. These calculations reveal that a nonlinear instability dominates the injection of energy into the turbulence by overtaking the linear drift wave instability that dom...

natural hazards such as earthquakes have threatened the life of human beings during the history.as a consequence, the vibration mitigation of structures has caught great importance. activecontrol of structures is one of the rapidly emerging areas in the concept of structural control. thispaper presents a control method to deal with this subject when the dynamics of the structure ishysteretic an...

We show, both theoretically and experimentally, that the interface between two viscous fluids in a Hele-Shaw cell can be nonlinearly unstable before the Saffman-Taylor linear instability point is reached. We identify the family of exact elastica solutions [Nye et al., Eur. J. Phys. 5, 73 (1984)]] as the unstable branch of the corresponding subcritical bifurcation which ends up at a topological ...

The dynamics of gaseous stars can be described by the EulerPoisson system. Inspired by Rein’s stability result for γ > 4 3 , we prove the nonlinear instability of steady states for the adiabatic exponent γ = 6 5 in spherically symmetric and isentropic motion.

The effect of surface tension on the Rayleigh-Taylor (RT) instability and Richtmyer – Meshkov (RM) instability induced development of nonlinear structures like spike and bubble at two fluid interface have been investigated .In case of RT instability, the surface tension reduces the velocity of the tip of both the bubble and the spike by the factor (1-k /3 kc ) where, kc =(h-l)g/T .For k > 3 k...

One of the most promising materials in nanotechnology such as sensors, actuators and resonators is annular Boron Nitride sheets (ABNSs) due to excelled electro-thermo-mechanical properties. In this study, however, differential quadrature method (DQM) and nonlocal piezoelasticity theory are used to investigate the nonlinear vibration response of embedded single-layered annular Boron Nitride shee...

Energy balance method is an effective and simple method which is used in the amplitude calculation of Aeolian vibration in transmission lines with Stockbridge damper. However, the accuracy of the results obtained by this method, heavily depends on the assumed mode shapes of the conductor vibration. In this study, by considering an appropriate model for the conductor vibration, a comprehensive m...