Um programa de ginástica para coronariopatas Coletânea de Exercícios Sugeridos

The acceleration of super-heavy ions (SHIs) from plasmas driven by ultrashort (tens of femtoseconds) laser pulses is a challenging topic waiting for breakthrough. The detecting and controlling of the ionization process, and the adoption of the optimal acceleration scheme are crucial for the generation of highly energetic SHIs. Here, we report the experimental results on the generation of deeply ionized super-heavy ions (Au) with unprecedented energy of 1.2 GeV utilizing ultrashort laser pulses (22 fs) at the intensity of 10^22 W/cm2. A novel self-calibrated diagnostic method was developed to acquire the absolute energy spectra and charge state distributions of Au ions abundant at the charge state of 51+ and reaching up to 61+. The measured charge state distributions supported by 2D particle-in-cell simulations serves as an additional tool to inspect the ionization dynamics associated with SHI acceleration, revealing that the laser intensity is the crucial parameter for the acceleration of Au ions over the pulse duration. The use of double-layer targets results in a prolongation of the acceleration time without sacrificing the strength of acceleration field, which is highly favorable for the generation of high-energy super heavy ions

Laser Filament Interaction with Aerosols and Clouds

A high powered ultrashort laser pulse can propagate as a diffraction-free self-channeled structure called a filament, created by a combination of nonlinear processes. With its ability to convey extremely high intensity beams to distant targets, many applications such as remote sensing, cloud seeding, and discharge guiding are potentially possible. However, one of the main challenges of outdoor field applications is the laser propagation through the atmosphere where pressure fluctuations and concentrations of aerosols may be present. The rationale behind the work presented in this dissertation is to evaluate the robustness of the filamentation, measure the interaction losses as well as understanding the modifications to (i) filament length (ii) supercontinuum generation, and (iii) the beam profile along propagation through perturbed media. Detailed studies of the interaction of a single filament with a single water droplet are presented. In addition, preliminary results on filament propagation through a cloud of aerosols are discussed. The effect of pressure on the beam profile along propagation and on the supercontinuum generated by the filament is studied. This document provides valuable insight into the complex nonlinear processes affecting the formation, propagation and post propagation of filaments under adverse atmospheric conditions

Filament Interaction With Micro-Water Droplets

The interaction of a laser filament with micro-sized water droplets was studied to further understand the energy dissipation of filaments in aerosol media. The analysis of the shockwave formation allows the quantification of the energy balance during the interaction and discuss the survival of filaments in perturbed propagation media. © 2014 OSA

Filament Interaction with Micro-Water Droplets

The interaction of a laser filament with micro-sized water droplets was studied to further understand the energy dissipation of filaments in aerosol media. The analysis of the shockwave formation allows the quantification of the energy balance during the interaction and discuss the survival of filaments in perturbed propagation media

Path integral formulation of light propagation in a static collisionless plasma, and its application to dynamic plasma

© 2020 OSA - The Optical Society. All rights reserved.In many studies on the laser impinging on a plasma surface, an assumption is made that the reflection of a laser pulse propagating to a plasma surface takes place only at the turning point, at which the plasma density exceeds the critical one. A general reflection amplitude of light R from an arbitrary inhomogeneous medium can be obtained by solving a Riccati-type integral equation, which can be solved analytically in low-reflection conditions, i.e., jRj2_1. In this work, we derive an intuitive analytic solution for the reflection amplitude of light R from a plasma surface by integrating all possible reflection paths given by the Fresnel equation. In the low-reflection condition, reflection paths having only one reflection event can be used. By considering the higher-order reflection paths, our analytic expression can describe reflection in the high-reflection condition. We show the results of a one-dimensional particle-in-cell simulation to support our discussions. Since our model derived for static plasmas is well corroborated by the simulation results, it can be a useful tool for analyzing light reflection from dynamically varying plasma

Interaction Of A Single Laser Filament With A Single Water Droplet

Time-resolved shock-wave studies allow the direct measurement of the energy dissipated during the interaction of a single laser filament in air with a water droplet. We show that the filament loses ∼40 μJ in energy for ∼50 μm diameter aerosols leaving sufficient residual energy for the formation of a fresh filament downstream

Spatial Dependence Of The Interaction Between A Single Aerosol And A Laser Filament On Its Reformation

The analysis of the filament destruction and reformation as a single aerosol is positioned along the radial and longitudinal axes of the filament provides more understanding of the propagation of filaments in aerosol-containing media

Interaction Between A Single Water Droplet And A Laser Filament

The analysis of the destruction and reformation of a single laser filament interacting with a single micro-sized water droplet allows a better understanding of filament propagation through atmospheric aerosols

Spatial Dependence Of The Interaction Between A Single Aerosol And A Laser Filament On Its Reformation

The analysis of the filament destruction and reformation as a single aerosol is positioned along the radial and longitudinal axes of the filament provides more understanding of the propagation of filaments in aerosol-containing media. © OSA 2015

Laser Induced Filament Propagation Through Adverse Conditions

Experimental studies of laser induced filament propagation through atmospheric conditions have been done to understand the interaction of filaments with its propagating medium as they propagate at different pressures and through aerosols