相关论文: Numerical Studies on Locally Damped Structures

A method of significantly reducing wakefields generated at collimators is proposed, in which the path of a beam is slightly bent before collimation. This is applicable for short bunches and can reduce the wakefields by a factor of around 7…

SuperKEKB is an asymmetric electron-positron circular collider based on nano-beam scheme at interaction region and large beam current. Large beam current makes growth rates of longitudinal coupled-bunch instabilities (LCBI) large.…

Interaction between the bunches in the NLC main linac via long range wakefields can cause a beam breakup instability. Although the magnitude of the long range wakefields for an ideal NLC structure is below the instability threshold, the…

This paper presents a new phasor measurement unit (PMU)-based wide-area damping control (WADC) method to suppress the critical inter-area modes of large-scale power systems. Modal participation factors, estimated by a practically model-free…

In this report we explore resonant multi-bunch, transverse wakefield effects in a linear accelerator in which the dipole modes of the accelerator structures have been detuned.

In this paper, we first design a type of Bang-Bang (BB) operation group to reduce the phase decoherence in a {\Xi}-type n-level quantum system based on the dynamical decoupling mechanism. Then, we derive two kinds of dynamical decoupling…

For a single hadron bunch affected by longitudinal space charge in a stationary rf bucket we analyze the frequency spectrum close to the expected loss of Landau damping for the lowest order dipole mode. For different bunch intensity…

The key feature of the improved coupling design in the Damped Detuned Structure (DDS) is focused on the four manifolds. Rectangular geometry slots and rectangular manifolds are used. This results in a significantly stronger coupling to the…

In particle accelerators, pumping holes in a vacuum chamber can be a source of unwanted broadband coupling impedance, leading to beam instabilities. Analytical methods have been previously developed to estimate the impedance of holes in…

A discrete time control algorithm using the damped least squares is introduced for acceleration and energy exchange controls in nonlinear vibrating systems. It is shown that the damping constant of least squares and sampling time step of…

Beam stability is an essential requirement for particle accelerators. Longitudinal coupled-bunch instabilities (CBI) are driven by beam interaction with long-range wakefields induced in the resonant structures with narrow-band impedance.…

A plasma beam dump uses the collective oscillations of plasma electrons to absorb the kinetic energy of a particle beam. In this paper, a modified passive plasma beam dump scheme is proposed using either a gradient or stepped plasma profile…

Piezoelectric nanopositioning systems are widely used in precision applications that require nanometer accuracy and high-speed motion; however, lightly damped resonances and pronounced cross-axis coupling severely limit bandwidth and…

We introduce a locally divergence-free local characteristic decomposition based path-conservative central-upwind (LCD-PCCU) scheme for ideal magnetohydrodynamics (MHD) equations. The proposed method is a low-dissipation extension of the…

As power systems become more and more interconnected, the inter-area oscillations has become a serious factor limiting large power transfer among different areas. Underdamped (Undamped) inter-area oscillations may cause system breakup and…

This paper investigates goal-directed tracking control of underactuated blimps with center-of-mass (CoM) reconfiguration. Unlike conventional overactuated blimp designs that rely on redundant actuation for simplified control, this paper…

Dipole wakefields in NLC (Next Linear Collider) structures have been measured with ASSET [1] and well predicted by a circuit model [2]. However, the experimental technique is both time-consuming and expensive. Here, we report on kick factor…

This letter proposes a decentralized local gain condition (LGC) to guarantee oscillation damping in inverter-based resource (IBR)-dominated power systems. The LGC constrains the dynamic gain between each IBR and the network at its point of…

We propose an empirical method for identifying low damped modes and corresponding mode shapes using frequency measurements from a Wide Area Monitoring System. The method consists of two main steps: Firstly, Complex Principal Component…

Landau damping mechanism plays a crucial role in providing single-bunch stability in LHC, High-Luminosity LHC, other existing as well as previous and future (like FCC) circular hadron accelerators. In this paper, the thresholds for the loss…