Theory of coherent radiatio n from a gratingwaveguide free electron laser yuanyao lin and yenchieh huang institute of photonics technologies, nati onal tsinghua university, hsinchu 30043, taiwan abstract a gratingwaveguide free electron laser can function as a mirrorless distributedfeedback oscillator near the bragg resonance, as well as a. Classical theory of freeelectron lasers book iopscience. This process is experimental and the keywords may be updated as the learning algorithm improves. The free electron laser fel will be an outstanding tool for research and industrial application.
Free electron lasers are laser devices where light amplification occurs by interaction with fast electrons in an undulator. Introduction to free electron lasers and fourthgeneration. Pdf highgain freeelectron laser theory, introduction. Treating the nearly free electron model using degenerate perturbation theory has been shown on the blackboard during lectures 3. Scheme of a conventional laser bound electron laser. A selfconsistent theory of the free electron laser instability is developed for a hollow electron beam propagating through an undulator multiple mirror magnetic field. The free electron laser instability for a solid relativistic electron beam propagating in combined transverse helical wiggler and uniform axial guide fields is investigated within the framework of. On the theory of the free electron laser springerlink.
For example, in the ir region, a pulsed optical parametric oscillator tunable over the 1,4501,800 cm. The stability analysis is carried out within the framework of the linearized vlasovmaxwell equations. Freeelectron lasers in the ultraviolet and xray regime. Were fast approaching the limits of our ability to hit maneuvering pieces of metal. The analysis continues on the basis of the similarity between undulator fel and other devices, based on the radiative emission from electrons, in order to give a feeling of the wealth of experimental and theoretical methods involved in the research on free electron laser. The nps institutional archive theses and dissertations thesis collection 199206 theory for a high power free electron laser and tactical applications. Photon quantum of energy outline light as waves light as particles. An electron trajectory jj j dmv ee v b dt the lorentz force equation for the jth electron is written. The free electron laser is one of the navys highestpriority weapons programs, and its not hard to see why. The freeelectron laser fel principle has been known since the early 1970s but. In the lectures we have derived two simple rules, which are away from brillouinzone boundaries the electronic bands i.
Simulation of input electron noise in the freeelectron laser. Theory for a high power free electron laser and tactical. Today such lasers are used for research in materials science, chemical technology, biophysical. The bohrs theory was making a simple, but efficient, assumption. Jefferson labs freeelectron laser is the worlds highestpower tunable infrared laser and was developed using the labs expertise in superconducting radiofrequency srf accelerators.
The treatment of a metal as containing a gas of electrons completely free to move within it. 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 free electron laser at stanford university today 22 free electron lasers operating worldwide 19 fels proposed or in construction. Unexpectedly, navys superlaser blasts away a record wired. Fel, the onedimensional theory of the highgain fel is developed in a systematic way. Classical theory of free electron lasers a text for students and researchers eric b szarmes chapter 1 introduction and overview 1. The fel also provides ultraviolet laser light, including vacuum ultraviolet light, and is also a source of terahertz light. The laser is a device which is today used in a wide list of fields. Experimental and numerical studies of the inverse free electron laser using a gwlevel 10. Va introduction to the physics of free electron laser. The nearlyfree electron model university of oxford.
In particular, this code has been used to simulate the laser electron beam interaction in an optical klystron. Lasers are used as research aides in many departments at princeton university. The term free electron laser fel will be used, in this paper, to indicate a wide collection of devices aimed at providing coherent electromagnetic radiation from a beam of free electrons. A motivation and introduction b theoretical approach c. The spent electron beams still have 99% of the initial energy. A free electron laser fel, is a type of laser whose lasing medium consists of veryhighspeed electrons moving freely through a magnetic structure, hence the term free electron. Laser mode laser field laser action free electron laser moving frame these keywords were added by machine and not by the authors. Physics of the free electron laser the free electron laser can produce intense, coherent light as the result of the interaction between an electron beam and an electric field of light. The center for free electron laser science as a joint enterprise of desy, the max planck society mpg, and the university of hamburg is designed to advance science with next generation light sources and lasers.
Theory of coherent radiation from a gratingwaveguide free. 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. 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. Pdf introduction to the physics of free electron laser. The very first electromagnetic radiation amplifier was built with ammonia in the range of microwaves and was called maser, for microwave amplification by stimulated emission of radiation. The free electron laser fel is a natural alternative as a radiation source national research council, 1982.
Electron injectors chapter chapter chapter chapter chapter chapter chapter. In an appendix a somewhat similar model for the photon, based on a virtual circular dielectric rod concept, is suggestedas a very speculative possibility, where the general theory of relativity may play a role. In physics, a quantum is the minimum unit of any physical entity involved in an interaction. Pelligrini, introduction to the physics of the free electron laser, laser handbook, vol. Pdf an introduction to the theory of free electron lasers. A free electron laser consists of an electron beam propagating through a periodic magnetic field. Rp photonics encyclopedia free electron lasers, fel. The term laser is an acronym for light amplification by. A high energy laser hel weapon system is an excellent candidate to fulfill this diverse role. If you want to obtain moving images of highspeed molecular processes at an atomic scale, one of the best facilities in the world is the xray free electron laser xfel at stanford university. We describe femtosecond xray diffraction data sets of viruses and nanoparticles collected at the linac coherent light source. The realization of a free electron laser fel operating in the quantum regime could provide a compact and monochromatic xray source. His current research interests include the theory and design of novel optical resonators for highresolution free electron laser spectroscopy, xray generation and highfield physics. Basic physical processes and principles of free electron lasers fels dagnachew w.
Free electron lasers lecture i brian mcneil, university of strathclyde, glasgow, scotland. 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. It is a gas laser built by ali javan at mit, with a wavelength of 632. In the second part the main elements of laser beam characterization are compiled with a. Fels based on jefferson labs superconducting electronaccelerating technology are being developed to process plastics, synthetic fibers, advanced materials, and metals as. 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. This chapter provides a detailed introduction to the 1d theory of highgain free electron laser fel and a brief overview of the 3d scaling function for fel gain. It is convenient to change the independent variable to z to get.
The light is emitted as the electron beam bunches into many very thin. Most of the ultrafast laser heating analysis to date has been accomplished with a constant electronphonon coupling factor g. The optical resonator with macroscopic dimensions that could store significant optical power at short wavelengths was crucial to the invention of the laser. E r,t 2 em wave is faster than electron, but periodic interaction if wave electron slippage is one wavelength per undulator period v s c u l u. Freeelectron laser an overview sciencedirect topics. In 1997 the navy distanced itself from supporting the free electron laser as a tool that could shoot. Fundamentals of light microscopy and electronic imaging. Physics of the freeelectron laser lasers, photonics, and. A brief discussion looks at highgain collective effects, short pulse effects, harmonics, energy spread and emittance, transverse diffraction, and noise.
The physics of free electron lasers by saldin, schneidmiller and yurkov and to. A free electron laser fel operating in the quantum regime can provide a compact and monochromatic xray source. Universal electron flood theory replaces standard models. Basic theory of free electron laser 1 low gain approximation we assume an initial, external e. Lectures on the free electron laser theory and related topics g. Losses in optical resonator of novosibirsk terahertz free. In this document, the word laser will be limited to electromagnetic radiationemitting devices using light amplification by stimulated emission of radiation at wavelengths from 180 nanometers to 1 millimeter. A free electron 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. Dumping the highpower electron beam is wasteful and creates radiation hazards e dump is beam energy before the beam dump. Accordingly, the cover shows the conjugate field and aperture planes of the light microscope under the title fundamentals of light microscopy and electronic imaging. Given its simplicity, it is surprisingly successful in. Freeelectron lasers in the ultraviolet and xray regime physical. Gover department of physical electronics, faculty of engineering, telaviv university, ramataviv, 69978 telaviv, israel received 15 february 1996. Sase free electron laser short pulse sase free electron laser wavelength range, nm 10.
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. E r,t 2 em wave is faster than electron, but periodic interaction if waveelectron slippage is one wavelength per undulator period v s c u l u. Sasefree electron laser short pulse sasefree electron laser wavelength range, nm 10. The essential features of the theory of the free electron laser fel are given in some detail. One electron volt is the energy gained by an electron when it has been accelerated by a potential difference of 1 volt, so that 1 ev 1. Path to understanding nobel symposium on free electron laser research june 14 18, 2015 sigtuna, sweden john m. The free electron 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. In 1998 he joined the faculty of the university of hawaii where he is currently an associate professor of physics. In the ultraviolet and x ray region one has to rely on the mechanism of self amplied spontaneous emission where the laser gain is achieved in a single passage of a very long.
Laser is an acronim for light amplification by stimulated emission of radiation. Wave fronts, propagating from points of the electron trajectory with maximum. 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. In solidstate physics, the free electron model is a simple model for the behaviour of charge carriers in a metallic solid. It is assumed that the beam is thin, with radial thickness much smaller. Because of a combination of theoretical, experimental, and technological advances, it is now possible to have xray freeelectron lasers. Highgain freeelectron lasers fels are being developed as extremely bright sources for a nextgeneration xray facility. The independent variable of the electron trajectory here is t, and only t. The central question addressed in this thesis is how to make the freeelectron laser fel more efficient. The effects on ifel acceleration with respect to the variation of the laser electric field, the input. Osa femtosecond freeelectron laser xray diffraction data. Basic physical processes and principles of free electron.
In recent years the use of diodepumped solidstate dpss lasers in oem applications has been growing rapidly. Introduction the word laser is an acronym for light amplification by stimulated emission of radiation. The role of electronphonon coupling in ultrafast laser. Due to the significant changes in the electron and lattice temperature caused by highpower laser heating, g could be temperature dependent. Theory and simulation of transverse supermode evolution in. Free electron laser a motivation and introduction c experimental realization challenges b theoretical approach v1. Simulation of laserelectron beam interaction in the optical. The atomic model can only work if neutrons were replaced with negative particles and light is one of those particles and has mass and then 100% works in all. How a quantum laser works an external source of energy excites electrons from the ground state to an. We proposed a novel type of free electron laser called the standingwave free electron laser for use as a power source in generating high accelerating gradients in next generation accelerators.
Extensions of the lorentzmaxwell theory are straight forward and can be solved analytically, or on a small computer. The theory was originally proposed in 1900 to describe and correlate the electrical and thermal properties of metals. In the onedimensional fel theory the dependencies on the transverse. N 1 to achieve the condition of population inversion between e 2 and e 1 at moderate pumping. Since the electron model is based directly on the special theory of relativity, it may also be used as an illustration of that theory. Theory and simulation of transverse supermode evolution in a free electron laser oscillator y. Microbunching as a result of the interaction of the electron bunch with an electromagnetic pulse is. In the following we sketch the fully classical theory following atomicmolecular laser theory based on the coupled maxwellbloch theory as it was first published in 1976.
The data establish the first large benchmark data sets for coherent diffraction methods freely available to the public, to bolster the development of algorithms that are essential for developing this novel approach as a useful imaging technique. The question of a classical theory of fel operation was very much in the air in the early days 19731976. Free electron laser fel theory is extended to explain several effects associated with high. Freeelectron lasers fels offer substantial cost and capability advantages including advantages for highvolume materials processing over other manufacturing tools. For visible or infrared light an optical resonator can be used. The free electron laser is tunable and has the widest frequency range of any laser type, 3 currently ranging in wavelength from microwaves, through terahertz. It was developed in 1927, principally by arnold sommerfeld, who combined the classical drude model with quantum mechanical fermidirac statistics and hence it is also known as the drudesommerfeld model. Each electron emits a wave train with n u cycles 1n u n u. The linac coherent light source free electron laser has now achieved coherent xray generation down to a wavelength of 1. 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. 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.
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