Femtosecond Bessel–Gauss beams are attractive tools to a large area of laser processes including high aspect ratio volume nanostructuration in dielectric materials. Understanding the material response femtosecond beam irradiation is key controlling its modifications and designing new structures. In this work, we show how ionization affects propagation can limit energy deposition. By performing ...

Knowledge of the beam profiles terahertz emitters is required for design instruments and applications, in particular designing communications links. We report measurements an optoelectronic silicon lens-integrated PIN-PD emitter at frequencies between 100 GHz 1 THz observe significant deviations from a Gaussian profile. The were found to differ H-plane E-plane, vary strongly with emitted freque...

Background: Vibro-acoustography is an elasticity imaging method that images the acoustic response of a material to a localized harmonic excitation generated by ultrasound radiation force [Fatemi and Greenleaf, Science 280:82-85, 1998]. Proper beam forming for the stress field (radiation force) of the probing ultrasound is very important because it determines the resolution of the imaging system...

The ordinary Portland cement (PC) manufacturing process emits toxic carbon dioxide into the environment. Minimizing consumption in construction industry is a major scholarly priority. This paper studies comparison of reinforced concrete and geopolymer beams, which rice husk ash (RHA) used as partial replacement for cement. study aims to determine optimum mix proportion with RHA (PC-RHA) (GC-RHA...

Performing Fast Ion Slow Ion Collision (FISIC) experiments is a long standing project for atomic collision physicists. Whereas such experiments are currently performed by high energy physicists, ion ion collisions for atomic physics have so far been performed only in the case of slow ions, in the context of magnetically confined plasmas. Besides the fundamental interest in understanding the mec...

We use Hamiltonian optics to design and analyze beam propagation in two-dimensional (2D) periodic structures with slowly varying nonuniformities. We extend a conventional Hamiltonian method, adding equations for calculating the width of a beam propagating in such structures, and quantify the range of validity of the extended Hamiltonian equations. For calculating the beam width, the equations a...

Neutralized drift compression offers an effective method for particle beam focusing and current amplification. In neutralized drift compression, a linear transverse and a longitudinal velocity tilt are applied to the beam pulse, so that the beam pulse compresses as it drifts in the drift-compression section. The beam intensity can increase more than a factor of 100 in both the radial and longit...

Introduction BNCT is an effective method to destroy brain tumoral cells while sparing the healthy tissues. The recommended flux for epithermal neutrons is 10 n/cms, which has the most effectiveness on deep-seated tumors. In this paper, it is indicated that using D-T neutron source and optimizing of Beam Shaping Assembly (BSA) leads to treating brain tumors in a reasonable time where all IAEA re...

The unwanted zero-order diffraction is still an issue in beam shaping using pixelated spatial light modulators. In this paper, we report a new approach for free by designing asymmetric triangle reflector and introducing digital blazed grating lens to the phase hologram addressed onto modulator. By adding previously reported complex-amplitude coding algorithms, realized generation of complex bea...