A megawatt (MW)class Free Electron Laser (FEL) as a point defense weapon system may lead to a revolution in anti-ship missile defense. Deep magazine low cost per shot proportional engagement capability and speed of light energy delivery provide the FEL with unmatched advantages over kinetic energy weapon systems. Before an FEL is made feet deployable stability system parameter optimization and operational utility all interest be taken into account. A short Rayleigh length FEL design is being considered in order to reduce system size and mitigate resonator minor damage. A short Rayleigh length thought can lead to vibrational sensitivities which must be studied. This thesis demonstrates that utilizing currently available technology and properly defined parameters a short Rayleigh length FEL should be able to achieve a MW of power. This thesis will also establish the viability of the FEE as a fleet deployable point defense weapon system through the development of a Concept of Operations (CONOPS) which draws from current naval warfare doctrine.

A megawatt (MW) class Free Electron Laser (FEL) shows promise as a new weapon for anti-ship cruise missile defense. An FEL weapon system delivers energy at the speed of light at controllable energy levels, giving the war fighter new engagement options. Considerations for this weapon system include employment, design, and stability. In order to reach a MW class laser, system parameters must be optimized and the high power optical beam must be appropriately managed. In a high power FEL, the optical beam could heat and ultimately damage the optical cavity mirrors. One proposed solution is a short Rayleigh length design, which lowers the intensity on the mirrors, but increases sensitivity to vibrations. This thesis shows a that short Rayleigh length FEL will remain stable using current technology and can be designed to achieve a MW of power. Scenarios are then presented to explore some of the engagement options associated with this weapon system.

The free electron laser (FEL) is among the latest technologies of interest to the U.S. military, in particular, the Navy. In naval applications, FEL laser would serve as a self-defense weapon system, protecting the ship from an array of threats including anti-surface cruise missiles and small boats. This system's potential range and deep magazine makes it ideal as point defense against incoming missiles. Its inexpensive cost of only a few dollars per engagement and multi-mission capability makes this future weapon system superior to the short-range missile-defense systems employed today. The most powerful FEL is currently located in Jefferson Lab, operating at 10 kW, two orders of magnitude short of the 1 MW power level required for weapons application. This thesis will describe the components and theory of operation of the FEL, as well as analyze two competing designs for the next step in the evolution of the future weapon system, the 100 kW FEL, proposed by Brookhaven and Los Alamos National Labs. Due to advances in NPS simulation techniques for the amplifier configuration, a more in depth analysis including the effects of electron beam tilt and shift is performed for the first time on these proposed designs.

This book presents a scientific assessment of free-electron-laser technology for naval applications. The charge from the Office of Naval Research was to assess whether the desired performance capabilities are achievable or whether fundamental limitations will prevent them from being realized. The present study identifies the highest-priority scientific and technical issues that must be resolved along the development path to achieve a megawatt-class free-electron laser. In accordance with the charge, the committee considered (and briefly describes) trade-offs between free-electron lasers and other types of lasers and weapon systems to show the advantages free-electron lasers offer over other types of systems for naval applications as well as their drawbacks. The primary advantages of free-electron lasers are associated with their energy delivery at the speed of light, selectable wavelength, and all-electric nature, while the trade-offs for free-electron lasers are their size, complexity, and relative robustness. Also, Despite the significant technical progress made in the development of high-average-power free-electron lasers, difficult technical challenges remain to be addressed in order to advance from present capability to megawatt-class power levels.

In order to improve ship self-defense against sea-skimming missiles, several concepts, such as the free electron laser, high-power microwaves, and the Phalanx gun system are reviewed and evaluated in this thesis. Phalanx computer simulations show that Phalanx is an inadequate means of protection. High-power microwaves are found to damage electronics, but calculations show limitations due to diffraction and the possibility of shielding. This thesis evaluates several damage mechanisms caused by the free electron laser's ultra- short picosecond pulse. Theories and experiments predicting the laser damage from short picosecond pulses are reviewed and applied to the fel weapon design. It is found that there may be a significant advantage to the ultra-short pulse format of an FEL weapon; as a result, new experiments are planned. As MW FELs are not yet a reality, this thesis uses computer simulations to explore FEL operation for many values of the electron pulse length, peak current and cavity desynchronism in order to explain recent Thomas Jefferson National Accelerator Facility (TJNAF) experimental observations of high average power.

The development of a high average power FEL for military applications, whether shipboard or not, represents a significant advancement in technology over present weapons systems design. The FEL has significant advantages over conventional kinetic systems and other classical high-energy laser systems. The rapid response, wavelength tunability, and infinite magazine make the FEL a highly desirable shipboard weapon system. The initial pan of this thesis examines the advantages of a FEL over a conventional kinetic weapon. Section II explores the atmospheric phenomenan that affects the propagation of a laser beam enroute to its target. Section III presents the Boeing FEL proposal followed by the theory of the FEL. Lastly, in Sections V, VI, simulations are conducted to analyze the FEL's feasibility.