The spin angular momentum (AM) of a light beam appears due to presence of circular or elliptic polarization. Its characterization is coupled with some paradoxical features which are commonly recognized but, to our opinion, are not satisfactorily explained in the known literature. Namely, for a spatially-homogeneous circularly polarized beam, the spin AM density is zero at every point of the bea...

This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5...

Analytical methods presented to analyze the buried steel pipelines at strike-slip fault crossing use the Euler-Bernoulli beam theory. The cross-section of a buried pipe that is completely surrounded by soil cannot rotate freely and would not be remained perpendicular to the bending line after deformation. So it would be better to take into consideration a rotation between the cross-section and ...

The method of complex geometrical optics (CGO) is presented, which describes Gaussian beam (GB) diffraction and self-focusing along a curvilinear trajectory in inhomogeneous and nonlinear saturable media. CGO method reduces the problem of Gaussian beam propagation in inhomogeneous and nonlinear media to solving ordinary differential equations for the complex curvature of the wave front and for ...

In this paper, a displacement-based, variationally consistent, two variable refined theory for shear deformable beams is presented. The beam is assumed to be of linearly elastic, homogeneous, isotropic material and has a uniform rectangular cross-section. In this theory, the beam axial displacement and beam transverse displacement consist of bending components and shearing components. The assum...

I present a derivation of the many qualitative changes to basic scattering theory that result when a ~partially! coherent matter beam inelastically interacts with a quantum target. The weak beam limit, where only one object in the beam interacts with the quantum target, is developed. Some of the basic changes to scattering theory are as follows. ~1! The transition probability can increase as th...

We are developing an acceptance measurement system to evaluate the matching of the emittance of an injection beam to the acceptance of the AVF cyclotron. The system is composed of a phase-space collimator in the low energy section and beam intensity monitors which are installed just after the phase space collimator and in the high energy section. The phase-space collimator, which consists of tw...

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...