Principles, properties and applications claudio pellegrini, ucla, and joachim stohr, ssrl 1. Moreover, we point out the necessity of a rigorous quantum theory for. Free electron laser fel theory is extended to explain several effects associated with high. A free electron laser utilizes a laser beam which is. The free electron laser fel will be an outstanding tool for research and industrial application. In the onedimensional fel theory the dependencies on the transverse. In fact fel is based on the stimulated emission of virtual photons by a relativistic. Sommerfeld theory of metals arnold sommerfeld 18681951 ece 407 spring 2009 farhan rana cornell university does not say anything about the electron energy distribution in metalsare all electrons moving around with about the same energy. On the theory of the free electron laser springerlink skip to main content.
N 1 to achieve the condition of population inversion between e 2 and e 1 at moderate pumping. Classical free electron theory of metals this theory was developed by drude and lorentz and hence is also known as drudelorentz theory. Andreas ringwald fundamental physics at free electron lasers, psi20, 812 september 20 page 11 pair creation from electron beam crossed with laser beam slac e144 studied nonlinear compton and stimulated pair production in the collision of a 46. All present realizations of a free electron laser fel can be solely described by classical physics. A selfconsistent theory of the free electron laser instability is developed for a hollow electron beam propagating through an undulator multiple mirror magnetic field. Introduction to free electron lasers and fourthgeneration light sources. Freeelectron laser a motivation and introduction c experimental realization challenges b theoretical approach. Recent results concerning the intrinsic linewidth and photon statistics of the free electron laser are also presented. The free electron laser was invented by john madey in 1971 at stanford university. Free electron lasers produced by the resonant interaction of a relativistic electron beam with a photon beam in an undulator tunable, powerful, coherent radiation sources 1977 first operation of a freeelectron laser at stanford university today 22 freeelectron lasers operating worldwide 19 fels proposed or in construction. The theory was originally proposed in 1900 to describe and correlate the electrical and thermal properties of metals. Colson institute of theoretical physics, department of physics, stanford university, stanford, california 94305, usa received 23 august 1976 radiation from electrons traveling through a static transverse periodic magnetic field is studied using classical, semiclassical.
In the following description of the fel theory we will consider the. Fel 2017 will focus on recent advances in free electron laser theory, experiments, electron beam, photon beam and undulator technologies, and some applications of free electron lasers. The helium neon laser the first continuouswave laser, the semiconductor diode laser, and aircooled ion lasers have found broad oem application. Threedimensional theory of the smithpurcell freeelectron laser.
January 3, 2018 abstract the e ect of electron phonon coupling in materials can be interpreted as a dressing of the electronic structure by the lattice vibration, leading to vibrational replicas and hybridization of electronic states. Lectures on the free electron laser theory and related topics. The process of harmonic generation in a seeded, single pass, free electron laser, are studied in the timefrequency domain following the evolution of the harmonics within a self consistent time. Kasparc zweites physikalisches institut aps april meeting 2006, dallas,tx thin film or functional coating.
A free electron model is the simplest way to represent. A short introduction to free electron lasers andy wolski the cockcroft institute, and the university of liverpool, uk cas general accelerator physics granada, spain, november 2012. Oscillator fel uses a combination of lowcurrent electron beam and an optical cavity to trap the optical pulse in several passes through the wiggler. Choosing the required parameters laser resonators for fels. A motivation and introduction b theoretical approach c. Recent advances in free electron laser theory nuclear instruments and methods in physics research section a. Handout 2 sommerfeld model for metals free fermion gas in this lecture you will learn. Free electron lasers free electron lasers fels are sources of synchrotron. Free electron laser continuous phase space high gain theory microbunching fel gain low gain theory. Free electron lasers an overview sciencedirect topics. The amplitude of the electric and magnetic elds in the radiation produced by the. In this thesis we developed a three dimensional 3d quantum theory for a fel with a laser wiggler, based on a discrete wigner function formalism taking into account the longitudinal momentum quantization.
Each electron emits a wave train with n u cycles 1n u n u. Pelligrini, introduction to the physics of the free electron laser, laser handbook, vol. The linear theory of a free electron laser based on a sheet beam propagating in a narrow gap is developed. You need an ereader or compatible software to experience the benefits of the epub3 file format.
The free electron laser was developed in 1971 and has slightly different operating mechanisms to other lasers. We look forward to welcoming you to beautiful santa fe, new mexico, usa. The classical theory of fels is an extension of the theory of the ubitron. Radiation from an oscillating electric charge consider a single oscillating electron.
Because of the wavelength scaling, the freeelectron laser is capable of producing very. The essential features of the theory of the free electron laser fel are given in some detail. It is a gas laser built by ali javan at mit, with a wavelength of 632. Dynamic theory of freeelectron laser with a reversed. A basic understanding of how a laser operates helps in understanding the hazards when using a laser device. The history of xray freeelectron lasers slac stanford university. The free electron laser fel has the most advantages, but a chemical laser proposed by trw is ready for installation on existing ships. Introduction creating matter from the vacuum, taking an atomic scale motion picture of a chemical. Free electron laser a motivation and introduction c experimental realization challenges. In basic terms, the free electron laser utilizes a laser. The freeelectron laser is tunable and has the widest frequency range of any laser type, currently ranging in wavelength from microwaves, through terahertz radiation and infrared, to the visible spectrum, ultraviolet, and xray. In this paper we consider the main reasons why a quantum theory of the freeelectron laser is of interest, and summarize and compare a number of different approaches, and their main results.
A schematic representation of an ray freeelectron laser, consisting typically of a x linear accelerator followed by an undulator magnet is shown in figure 2. Theory of a free electron laser harvard university. Relativistic spacecharge wave theory is developed systematically, and is for the first time used to establish the linear theory of the free electron laser fel. Initial testing of issues related to directed energy use at sea can be conducted with the chemical. Fel, free electron laser, attosecond, european xfel, xleap, dch some. A freeelectron laser fel is a kind of laser whose lasing medium consists of veryhighspeed. This theory is called quantum free electron theory. Pdf introduction to the physics of free electron laser and. Each pass involves a new electron bunch interacting with the optical field and undergoing microbunching at the end of the wiggler.
In this paper the physical process of new type of coherent. The free electron laser has been around since 1971 and has slightly different operating mechanisms to other lasers. Based on desired quantum fel properties, as well as current. The treatment of a metal as containing a gas of electrons completely free to move within it. Handout 2 sommerfeld model for metals free fermion gas. Beginning with an explanation of the basic gain mechanism, the lectures continue with a discussion. The theoretical treatment throughout this book is fully developed by means of the usual threedimensional vector calculus. The effects on ifel acceleration with respect to the variation of the laser electric field, the input. Center for free electron laser science, 22761 hamburg. Since 6qa x bx is parallel to the z direction it can be deduced from eq. The free electrons traverse a series of alternating magnets, called a wiggler, and radiate light at wavelengths depending on electrons energy, wiggler period and magnetic field. Theory and simulations predicts third harmonic reaches up. A fully selfconsistent theory of the free electron laser is derived in the collective regime which includes all transverse variations in the wiggler field as well as the effects of a finite waveguide geometry.
His current research interests include the theory and design of novel optical resonators for highresolution free electron laser spectroscopy, xray generation and highfield physics. The free electron laser utilizes technology developed by hans motz and his coworkers, who built an undulator at stanford in 1953, using the wiggler magnetic configuration which is one component of a free electron laser. A freeelectron laser consists of an electron beam propagating through a periodic magnetic field. Physica 123c 1984 225237 northholland, amsterdam theory of the free electron laser hiroshi takahashi brookhaven national laboratory, upton, ny 11973, usa received 29 october 1980 revised august 1981 rerevised 20 april 1983 photon propagation in a relativistic electron beam, interacting with a static helical magnetic field b, is described by using the quantum mechanical twotime green. A freeelectron laser fel is a kind of laser whose lasing medium consists of veryhighspeed electrons moving freely through a magnetic structure, hence the term free electron. Introduction to freeelectron lasers neil thompson astec. Experimental and numerical studies of the inverse free electron laser using a gwlevel 10. Free electron lasers free electron lasers fels are sources of synchrotron radiation that can produce radiation with peak power and brightness orders of magnitude larger than the radiation produced by conventional sources such as dipoles and wigglers. Classical relativistic electrodynamics theory of light. This book describes the physical fundamentals on the basis of classical mechanics, electrodynamics, and the kinetic theory of charged particle beams, and will be suitable for graduate students and scientists alike.
Introduction creating matter from the vacuum, taking an. Andrews, department of physic s and astronomy, vanderbilt university, nashville, tn 37235, u. The new quantum mechanics, when applied to the problem of the structure of the atom with pointcharge electrons, does not give results in agreement with experiment. A short introduction to free electron lasers andy wolski. The stability analysis is carried out within the framework of the linearized vlasovmaxwell equations. But quantum free electron theory permits only a fraction of electrons to gain energy. It is assumed that the beam is thin, with radial thickness much smaller. Basic physical processes and principles of free electron. Laser fundamentals federation of american scientists. Fundamentals, types, and operations n n e 0 e e 1 e 3 e 0 e e 1 2 fast decay fast decay fast decay pumping pumping lasing lasing a b figure 1. C experimental realization challenges free electron laser linac coherent light source lcls scales challenges rf gun. A theory for optical wavelength control in short pulse. Pdf this report is a primer introduction on the sources of coherent syncrotron. Workie department of physics university of cincinnati cincinnati, ohio 45221 november 26, 01 abstract a tunable coherent and high peak power sources have been very usefull in many applications.
List of fel 17 participants pdf on behalf of the international executive committee of the fel conference series, we are pleased to announce the 38th international free electron laser conference fel2017, to be held at the santa fe community convention center sfccc in santa fe, new mexico, usa from august 20th to august 25th, 2017. Today such lasers are used for research in materials science, chemical technology, biophysical science, medical applications, surface studies, and solidstate physics. Threedimensional theory of the raman freeelectron laser. Atomic selectrons are delocalised due to overlap of outer orbits. The term laser originated as an acronym for light amplification by stimulated emission of radiation. Classical free electron theory permits all electrons to gain energy. Figure 2 shows that electromagnetic radiation is emitted whenever a charged particle such as an electron gives up energy. The realization of a free electron laser fel operating in the quantum regime could provide a compact and monochromatic xray source. Introduction to free electron lasers and fourthgeneration. Laser emission is studied vs interaction time with a varied number of electrons. Threedimensional nonlinear theory of the free electron laser. On the theory of the free electron laser springerlink.
It reveals the physical essentials of the electron bunching process and the particlewave interaction mechanisms in fels. In this thesis, however, we are dealing with a parameter regime in which quantum effects become important. Shaoen jiang dynamic theory of freeelectron laser with a reversed axialguide magnetic field, proc. Basic physical processes and principles of free electron lasers fels dagnachew w. Introduction the availability of free electron lasers fels operating in the short wavelength regime 15 has tremendously increased the research. A 1d theory of a sasefel, describing all the basic properties of a. Classical, semiclassical, and quantum field theories are used to investigate the possibility of a laser based on stimulated emission from relativistic free electrons traveling through a static, transverse, periodic magnetic field. In 1998 he joined the faculty of the university of hawaii where he is currently an associate professor of physics. According to this theory, a metal consists of electrons which are free to move about in the crystal like molecules of a gas in a container. In a freeelectron laser fel the lasing medium is a highenergy beam of. To understand the properties of the radiation emitted consider initially the simple case of only one electron propagating through the undulator. Classical theory of freeelectron lasers book iopscience. Pdf a freeelectron laser consists of an electron beam propagating through a periodic magnetic field. Accelerators, spectrometers, detectors and associated equipment, vol.
The free electron laser fel differs from conventional lasers in having a gain medium consisting of free electrons. Takahashi theory of the free electron laser diagonal term of the matrix crl a2, which accounts for the nonspin flip electronphoton interaction process, becomes the. Freeelectron theory of metals article about freeelectron. W 1000 photoeffect from the quantum vacuum positive energy states negative energy states dirac sea production of electron positron pairs according to emc2 from laser photons possible, if h. Specifically, it provides readers with the basics of advanced electromagnetic theory and relativistic electrodynamics, guiding them step by step through the theory of free electron lasers. Center for free electron laser science, 22761 hamburg, germany dated.
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