Nanoporous structures have a great potential for application in electronic and photonic materials, including field effect transistors, photonic crystals, and quantum dots. The control of size and shape is important for such applications. In this study, nanoporous structure formation on the indium antimonide (InSb) surface was investigated using controlled focused ion beam irradiation. Upon incr...

A number of methods for producing sub-picosecond electron bunches have been demonstrated in recent years. A train of these bunches is capable of generating THz radiation via multiple mechanisms like transition, Cherenkov and undulator radiation. We propose to use a bunch train like this to selectively excite a high order mode in a dielectric wakefield structure. This allows us to use wakefield ...

The aim of this paper is firstly to address the consequences of the nonlinear interactions between higher order modes and the first order mode of a flexible cantilever beam. The tested cantilever beam exhibited numerous nonlinear phenomena that are commonly observed in many flexible structures. The experimental results have shown that active control of the nonlinear vibration in a flexible stru...

The metal surface of accelerating structures emits electron currents when operating at rf electric fields higher than 100 MV/m. These “dark currents” may have deleterious effects such as creating backgrounds for beam diagnostics, generating X-rays, loading rf power. They will also interact with the primary electron (or positron) bunch being accelerated in the structure, to kick the beam centroi...

Steel corrosion of bars in concrete structures is a complex process which leads to the reduction of the cross-section bars and decreasing the resistance of the concrete and steel materials. In this study, reliability analysis of a reinforced concrete beam with corrosion defects under the distributed load was investigated using the enhanced Hasofer-Lind and Rackwitz-Fiessler (EHL-RF) method base...

Because of special structure, a dual reflector antenna has beam rotation capability in azimuth and elevation directions. In this structure, the antenna beam can be placed in any point in the space by mechanical movement of twist reflector which it is the most important ability of the antenna. Due to the antenna structure, if the polarization of incident wave is linear, it is expected that the p...

The application of transformation optical techniques to photonic crystal-like dielectric structures has facilitated the creation of invisibility cloaks that operate at optical wavelengths. In this article, the authors present the fabrication processes for an all-dielectric ground plane cloak structure that consists of multiple silicon nanorod arrays connected by input and output waveguides. An ...

Hook-like surface structures, observed in some plant species, play an important role in the process of plant growth and seed dispersal. In this study, we developed an elastic model and further used it to investigate the mechanical behaviour of fruit hooks in four plant species, previously measured in an experimental study. Based on Euler-Bernoulli beam theory, the force-displacement relationshi...

We review the generation of the recently predicted multi-component spatial optical solitons in a saturable nonlinear bulk medium. We present numerical simulations for an effectively isotropic model and experimental results for a set of different combinations of a Gaussian beam co-propagating incoherently with a beam of a more complex internal structure, such as a higher order transverse laser m...

A b&act A key problem in next-generation linear collider designs utilizing multibunching is the control of multibunch beam break-up. One method of controlling the break-up is detuning, i.e., varying the frequency of the transverse deflecting modes by varying the cell dimensions within the.accelerating structures. In this case, the beam break-.up is sensitive to the resonances between the bunch ...