The excitation of ion azimuthal surface oscillations with extraordinary polarization by light ion beam is studied analytically. Beam-plasma system consists of a cylindrical metal waveguide filled partially by cold magnetized plasma and light ion flow rotating around the plasma column. Dependencies of the beam instability growth rate on the system parameters (plasma and beam densities, value of ...

Surface modes in a Bose-Einstein condensate of sodium atoms have been studied. We observed excitations of standing and rotating quadrupolar and hexadecapolar modes. The modes were excited with high spatial and temporal resolution using the optical dipole force of a rapidly scanning laser beam. This novel technique is very flexible and should be useful for the study of rotating Bose-Einstein con...

Multi-beam lidar (MBL) rangefinders are becoming increasingly compact, light, and accessible 3D sensors, but they offer limited vertical resolution and field of view. The addition of a degree-of-freedom to build a rotating multi-beam lidar (RMBL) has the potential to become a common solution for affordable rapid full-3D high resolution scans. However, the overlapping of multiple-beams caused by...

Laser beam homogenizing and beam shaping are key enabling technologies for many applications today. Periodic microlens arrays are widely used to transform Gaussian or non-uniform beam profile into a uniform “flat-top”. Each microlens element samples the input beam and spreads it over a given angular distribution. Incoherent beams that are either temporally or spatially incoherent can produce ve...

A rotating-and-warping projector / backprojector is proposed for iterative algorithms used to reconstruct fanbeam and cone-beam single photon emission computed tomography (SPECT) data. The development of a new projector/ backprojector for implementing attenuation, geometric point response, and scatter models is motivated by the need to reduce the computation time yet to preserve the fidelity of...

The beam dump is a critical component for the in-flight fragment separator using high-power primary beams at the rare isotope science project (RISP) in Korea. The maximum beam power is planned to be 400 kW, and a third of the primary beam power deposits at the isotope production target and the rest are dissipated at the beam dump. The beam dump is designed to be a rotating water drum, which is ...

Non-prismatic beams have received great attention from engineers due to their capability in optimizing the strength and weight of the structure. In recent years, many researchers have worked on engineering problems related to static and dynamic analysis of either Euler–Bernoulli [1–3] or Timoshenko [4,5] beams. For short thick beams and rotating machineries, the Timoshenko beam theory presents ...

A multichannel interferometer that uses a rotating grating to both disperse and Doppler shift an incident far-infrared laser beam is described. The laser beam is diffracted into a fan array of many (~ 10) beams that can be directed to probe the plasma along distinct chords. The phase-shift information is multiplexed in the frequency domain so that a single detector suffices to sense the recombi...

The equation of motion of a rotating cantilever beam in a vertical plane is derived based on Hamilton’s principle and assumed mode method. The effect of gravity on the stability of the beam with constant angular velocity is then examined using Bolotin’s method. The regions of ins~bi~ity are determined by converting the resulting equations of boundary frequencies to the standard form of a genera...

abstract: in this paper, nonlocal euler–bernoulli beam theory is employed for transverse vibration analysis of an initially pre-stressed size-dependent rotating nanotube. the nonlocal eringen theory takes into account the effect of small size, which enables the present model to become effective in the analysis and design of nanosensors and nanoactuators. governing equations are derived through ...