Journal of Directed Energy
Volume 1, Number 1
The papers listed below constitute Volume 1, Number 1 of the Journal of Directed Energy.
Print copies of this, and other issues of the Journal of Directed Energy are available through the
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Enjoy access to the complete technical paper(s) through links in the paper titles.
Welcome to a New Forum for Directed Energy Research and Technology
P.M. Sforza and H. Zmuda, DEPS
A peer-reviewed, archival Journal for communications within the Directed Energy community is inaugurated.
KEYWORDS: Journal of Directed Energy
High Energy Laser Weapons for the Fleet
R.D. McGinnis and A. Skolnick, Naval Sea Systems Command and other affiliations
A historical retrospective of Navy high-energy laser (HEL) development is combined with a comprehensive discussion
of mission-related motivations for ultimate operational usage of HEL weapons in the Fleet. Discussion is provided
that highlights the changed circumstances over the past two decades that have renewed Navy interest
in directed energy weapon opportunities. The unique characteristics of HELs relative to both today's
operational needs and future Navy requirements are reviewed. Current status and future prospects for particular
laser device development paths as well as special technology challenges (beam control) facing the eventual delivery
of practical and useful weapon systems are discussed. These issues are all addressed from the perspective of the
authors, sea-experienced naval officers and seasoned program managers, who have held or currently hold full
accountability for Navy directed energy weapon progress.
KEYWORDS: Directed energy weapons, Future prospects for Navy laser weapons, High-energy lasers, History and status of Navy laser weapons
Virtual Prototyping of Radio Frequency Weapons
K.L. Cartwright, A.D. Greenwood, P.J. Mardahl, T. Murphy, and M.D. Haworth; Air Force Research Laboratory
This paper explains how radio frequency (RF) systems, from pulsed power through to antennas, can be virtually
prototyped with the ICEPIC (Improved Concurrent Electromagnetic Particle-in-Cell) code. ICEPIC simulates
from first principles (Maxwell's equations and Lorenz's force law) the electrodynamics and charged-particle
dynamics of the RF-producing part of the system. We discuss features such as multiprocessing on distributed
memory machines, dynamic load balancing, and the mitigation of numerical Cerenkov radiation in the field solve.
Simulations focus on gigawatt-class sources; shown as an example will be the magnetically insulated line
oscillator (MILO). Such simulations require enormous computational resources. Our simulations successfully
expose undesirable features of these sources and have helped us to suggest improvements.
KEYWORDS: FTDT, Parallel PIC, Plasma simulation
Tactical High Energy Laser
J. Shwartz and others, Northrup Grumman Space Technology and other affiliations
The tactical high energy laser (THEL) is a ground-based stationary laser weapon demonstrator jointly developed
by the U.S. Army and the Israel Ministry of Defense (IMoD). Its specific mission was to engage and destroy artillery
rockets and similar ballistic threats. By now this demonstrator has shot down 28 artillery rockets and 5 artillery
projectiles under a wide range of engagement scenarios, clearly demonstrating the feasibility of using a laser
weapon to defend against such threats. Following the success of the THEL program, the U.S. Army and IMoD
embarked on a System Engineering and Trade Study (SETS) program to define concepts for a mobile THEL (or MTHEL)
that will be a fully operational and militarized laser weapon capable of defending against a wide range of
aerial threats, as well as short-range ballistic threats. Several concepts were developed and are being
fleshed out and traded to help decide which one will best serve the requirements of the U.S. Army and IMoD.
This paper starts with a brief overview of the THEL history and then provides a detailed description of the
THEL system. The live-fire tests performed with THEL at the U.S. Army's White Sands Missile Range, in New Mexico,
are briefly reviewed, and a MTHEL concept is also described in some detail. The paper concludes with a summary
that highlights the significance of the THEL development and test program as a pathfinder for introducing a
revolutionary air defense capability that can potentially change the face of the battlefield.
KEYWORDS: Lasers for Air Defense, Laser Weapon Demonstrator, Tactical Lasers
Compact Pulsed Power for Directed Energy Weapons
D. Price and others, Titan Corporation
The Titan Corporation has been developing directed energy technologies since the early 1980s. Over this time Titan has
provided advanced power supplies for electromagnetic gun and laser research while making broader contributions in
the field of high-power microwaves (HPM). Titan's HPM work expanded from initial efforts fielding and operating
the fist gigawatt-level oscillators for susceptibility test applications, to research and development maximizing
the peak and average output powers and overall efficiency realized from such systems. As interest in HPM technology
has spread globally, Titan has leveraged this core competency and provided the HPM equipment for nearly all of the
major European effects test facilities. Titan's current interests focus on compact, efficient and reliable directed
energy weapon systems and the advanced subsystems and components that enable the same. Specific subsystems of
interest include pulse-forming networks and intermediate energy storage and power conditioning elements
(electronically reconfigurable batteries and power ride-thru subsystems). These subsystems are designed for
reduced size and weight while still meeting severe service, platform integration, lifetime, and thermal management
constraints. Specific components under development at Titan include laser-gated solid-state switches and both high
peak and high average power, frequency-agile, HPM oscillators. Status and recent results from this research are
KEYWORDS: Electronically reconfigurable batteries, High-power microwaves, Laser-gated solid-state switches, Magnetron, Power-ride thru. Pulsed power, Relatron
Propagation of Short, High-Intensity Laser Pulses in Air
P. Sprangle, J.R. Penano, A. Ting, B. Hafizi, and D.F. Gordon; Naval Research Laboratory
The atmospheric propagation of high-intensity, high-average-power laser beams is important for a number of directed energy
applications. Linear as well as nonlinear processes affect atmospheric propagation of short, intense laser pulses.
A set of equations for modeling the three-dimensional atmospheric propagation of intense short laser pulses is presented
and discussed. The equations account for the linear propagation effects of dispersion, absorption, scattering, and
turbulence. The nonlinear propagation effects included are transient thermal blooming, bound electron anharmonicity
(optical Kerr effect), stimulated Raman scattering, ionization, plasma response (wakefields), and relativistic quiver
motion. In many applications nonlinear effects, turbulence, and dispersion are important because of the short laser
pulse durations and high peak intensities. The equations are used to study the propagation of a single laser pulse with
peak power in the gigawatt range. Examples illustrate several important processes that would be associated with directed
energy applications of intense laser beams, such as a free-electron laser with peak (average) power in the gigawatt
KEYWORDS: Atmospheric propagation, Blooming, Free-electron laser, Turbulence
Journal of Directed Energy, Volume 1, Number 1