When an ion beam is injected into a tapered insulating capillary, the induced self-organized radial Coulomb potential in capillary able to focus like electrostatic lens. However, because of continued accumulation charge equilibrium rarely attained and eventually blocked by capillary's potential. We propose original add-on setup, which can be tested experimentally expected hinder blocking. inves...

We report the spatial beam self-cleaning in bi-tapered conventional multimode fibers (MMFs) with different tapered lengths. Through introduction of structure MMFs, input poor quality from a high-power fiber laser can be converted to centered, bell-shaped short length, due strengthened nonlinear modes coupling. It is found that MMF longer length at same waist diameter shows better effect and lar...

A self-scanning, highly-efficient electron beam source is being built for electron beam dry scrubbing (EBDS) of flue gases. The beam is to be prepared using cyclotron autoresonance acceleration (CARA), which has already experimentally demonstrated an rf efficiency above 90%. The design is based on simulation studies for a 250-kV, 25-A warm injected beam which is accelerated in a 112cm long CARA...

In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well w...

Theory is developed for the cyclotron autoresonance acceleration of electrons in a gently-focused Gaussian laser beam and a gently tapered axial magnetic field. Numerical simulation shows, for example, acceleration from 50 MeV to 178 MeV over a distance of 148 cm, using a 10.6 μm CO2 laser with a minimum spot size of 0.1 cm.

To a good approximation, the electromagnetic-propagation characteristics of graded-index waveguides can be written in terms of polynomial-Gaussian modes. For uniform quadratic-index waveguides the behavior of these modes is well known. However, there are sometimes practical reasons for using tapered waveguides, but detailed propagation solutions are known for only a few specific taper functions...

We study the dependence of the peak power of a 1.5 Å Terawatt (TW), tapered x-ray free-electron laser (FEL) on the transverse electron density distribution. Multidimensional optimization schemes for TW hard x-ray free-electron lasers are applied to the cases of transversely uniform and parabolic electron beam distributions and compared to a Gaussian distribution. The optimizations are performed...