Small sand molds for aluminum casting were produced by selective laser sintering (SLS) of pre-coated sands. A diode laser source with a rectangular laser beam spot was used to perform single and multi-layer processing tests. Subsequently, small sand molds were produced and tested in casting operations. Single layer processing was performed by changing laser power, scan rate and distance of the ...

One of the solutions of the Helmholtz equation is the vortex beams. In the recent decades, production and applications of these types of beams have found serious attentions. Determination of the vortex beam topological charge and its sign are very important issues. Odd number of reflections of the vortex beam changes its vorticity. In this paper, we have used a q-plate to generate a vortex beam...

The laser beam profiles captured by CCD camera processed and analyzed by using 2Dgraphic and displayed on the monitor. The analysis of the He-Ne profiles and laser diode profiles are presented. The results showed that the He-Ne laser emits a pure Gaussian beam, whereas the diode laser emits an elliptical beam shape. The laser beam profile analysis developed to study the intensity distribution, ...

In this paper, the dynamic behavior of laser induced optical breakdown in impure water was studied by using a pump- probe technique. The plasma was induced by a 1064 nm Nd:YAG laser pulse (with pulse duration ~10 ns) in distilled water with two types of impurities: (I) a solution (highly diluted salt water as a conductor) and (II) a colloidal (TiO2 in colloidal nanoparticle form as a dielectric...

Micro size craters were created by interaction of nanosecond laser beam with titanium target in liquid media. The dimension of crater i.e. depth and width is important in some applications such as micromachining. When the interaction occurs in liquid environment, the ablated materials from the target expand into the liquid. The ablated material can affect the interaction process if the ablated ...

A new scheme for the two-dimensional cooling of ion beams in storage rings is suggested in which ions interact with a counterpropagating broad-band laser beam. The interaction region in the direction of the ion movement is much less then the wavelength of the ion betatron oscillations. The laser beam in the orbit plane has sharp flat edge directed to the ion beam and the width of the laser beam...

Title of Document: INTENSE LASER ACCELERATION OF QUASI-MONOENERGETIC PROTONS Tung-Chang Liu, Doctor of Philosophy, 2013 Directed By: Professor Chuan S Liu, Physics By irradiating an ultra-thin overdense foil with an intense circularly polarized laser beam, the laser radiation pressure can push the foil forward. This scheme, laser radiation pressure acceleration, is one of the most actively stud...

High-definition patterns were observed under 10-Hz-pulse-repetition-rate, nanosecond laser irradiation of azodye-doped planar-nematic liquid crystal layers at incident intensities I 5–10 MW=cm in a single beam configuration and without any feedback involved. An incident polarization parallel to the nematic director was used. Under periodic pulsed laser irradiation, far-field beam patterns at th...

1. In existing projects of electron-positron colliders, the option of polarized electron and positron beams is considered [1,2]. While one can consider the problem of producing the polarized electron beams with required characteristics as having been solved [3], the existing approaches to polarized positrons generation [4-7] do not provide required parameters. In quoted papers the schemes were ...

Science Diliman (July–December 2004) 16:2, 106-109 A theoretical model that computes both for the gradient and scattering forces being exerted on a nonresonant nonlinear (electro-optic Kerr effect) rigid nanosphere by a strongly focused continuous-wave laser beam is presented. The incident wavelength of the laser beam is assumed to be appreciably larger than the nanosphere radius a. Optical for...