Gas-dispersed active medium for high-energy HF/DF laser systems based on a photon-branched chain reaction

2007 ◽  
Author(s):  
Renat R. Letfullin ◽  
Thomas F. George
Keyword(s):  
Active Medium ◽  
High Energy ◽  
Chain Reaction ◽  
Laser Systems ◽  
Branched Chain

scholarly journals Laser-Induced Photon-Branched Chain Reaction in a Chemically-Active Gas-Dispersed Medium

2008 ◽  
Vol 2008 ◽  
pp. 1-10
Author(s):  
Renat R. Letfullin ◽  
Thomas F. George ◽  
Galen C. Duree
Keyword(s):  
Active Medium ◽  
High Energy ◽  
Extensive Study ◽  
Chain Process ◽  
Chain Reaction ◽  
Two Phase ◽  
Dispersed Medium ◽  
Branched Chain ◽  
Short Time ◽  
Promising Avenue

A promising avenue in the development of high-energy pulsed chemical HF/DF lasers and amplifiers is the utilization of a photon-branched chain reaction initiated in a two-phase active medium, that is, a medium containing a laser working gas and ultradispersed passivated metal particles. These particles are evaporated under the action of IR laser radiation which results in the appearance of free atoms, their diffusion into the gas, and the development of a photon-branching chain process, which involves photons as both reactants and products. The key obstacle here is the formation of a relatively large volume (in excess of 103 cm3) of the stable active medium and filling this volume homogeneously for a short time with a submicron monodisperse metal aerosol, which has specified properties. In this paper, results are presented for an extensive study of laser initiation of a photon-branched chain reaction in a gas-dispersed H2–F2 medium.

State-of-the-art Laser Ceramics for the Next-generation Solid-state Laser

2021 ◽  
Vol 30 (10) ◽  
pp. 22-27
Author(s):  
Ho Jin MA ◽  
Ha-Neul KIM
Keyword(s):  
Solid State ◽  
Mechanical Characteristics ◽  
High Energy ◽  
Solid State Lasers ◽  
Laser Ceramics ◽  
Host Materials ◽  
Laser Systems ◽  
Energy Laser ◽  
High Energy Laser ◽  
Gain Media

Solid-state lasers have aroused many researchers’ interests for a variety of applications in military and industrial fields. Because of the preference for increased output power, Nd:YAG single crystals, which are the most widely used gain media, should be replaced by other more suitable candidates. Polycrystalline sesquioxide ceramics show great potential for use as gain media because their thermal and mechanical characteristics are suitable for use with high-energy laser systems. Recently, novel concepts of the gain media were also introduced. Herein, while briefly looking back on the progress of polycrystalline laser ceramics, we will discuss new interests in host materials and systems.

Yb:YAG disc for high energy laser systems

2017 ◽  
Author(s):  
Karel Nejezchleb ◽  
Jan Kubát ◽  
Jan Šulc ◽  
Helena Jelínková
Keyword(s):  
High Energy ◽  
Laser Systems ◽  
Energy Laser ◽  
High Energy Laser

scholarly journals On the explosion of chain-thermal reactions

1982 ◽  
Vol 24 (2) ◽  
pp. 194-202 ◽  
Author(s):  
R. O. Ayeni
Keyword(s):  
Activation Energy ◽  
Asymptotic Analysis ◽  
Upper Bound ◽  
Homogeneous Model ◽  
Chain Reaction ◽  
Isothermal Reaction ◽  
Thermal Reactions ◽  
Spatially Homogeneous ◽  
Branched Chain ◽  
A Chain

AbstractA chain reaction of oxygen (reactant) and hydrogen (active intermediary) with mtrosyl chloride (sensitizer) as a catalyst may be modelled mathematically as a non-isothermal reaction. In this paper we present an asymptotic analysis of a spatially homogeneous model of a non-isothermal branched-chain reaction. Of particular interest is the so-called explosion time and we provide an upper bound for it as a function of the activation energy which can vary over all positive values. We also establish a bound on the temperature when the activation energy is finite.

Linear model predictive control for vision-based UAV pursuit

2020 ◽  
Vol 8 (4) ◽  
pp. 334-363 ◽  
Author(s):  
Christopher C. Surma ◽  
Martin Barczyk
Keyword(s):  
Model Predictive Control ◽  
Linear Model ◽  
Predictive Control ◽  
High Energy ◽  
Aerial Videography ◽  
Combined Control ◽  
Communication Devices ◽  
Laser Systems ◽  
Commercial Off The Shelf ◽  
Set Up

This article develops and implements a vision-based unmanned aerial vehicle (UAV)-to-UAV pursuit system using a commercial off-the-shelf Parrot AR.Drone 2.0 quadrotor. This technology is intended as a countermeasure to rogue drones carrying out activities such as flying in restricted airspace, performing unauthorized aerial videography, transporting contraband and other criminal activities, or being used as improvised weapons. The proposed approach offers benefits over other current solutions, such as wide-area radio-frequency jamming that interferes with regular communication devices or high-energy military laser systems that are expensive and time consuming to set up. A linear dynamics model of the AR.Drone 2.0 vehicle stabilized by its onboard feedback control system is derived, and its parameters are experimentally identified. A linear model predictive control is developed to track specified flight trajectories, then implemented and validated in hardware flight tests. Detection and ranging of the target UAV from the pursuer UAV’s onboard monocular camera are performed using the YOLO v2 convolutional neural network algorithm. The combined control and vision design is implemented in hardware and tested quantitatively in flight experiments.

Control of pulse format in high energy per pulse all-fiber erbium/ytterbium laser systems

2017 ◽  
Author(s):  
Michael Klopfer ◽  
Matthew K. Block ◽  
James Deffenbaugh ◽  
Zak G. Fitzpatrick ◽  
Michael T. Urioste ◽  
...  
Keyword(s):  
High Energy ◽  
Laser Systems
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