A short history of electron sources for and the operating characteristics of the free. Due to their wide range tunabilty and high brghtness they have a growing applications. Handout 2 sommerfeld model for metals free fermion gas. Freeelectron laser a motivation and introduction c experimental realization challenges b theoretical approach.
Phasemerging enhanced harmonic generation freeelectron laser. Va, and a major upgrade underway to a 10kw class device, freeelectron lasers fel must now be considered a serious option for military directed energy weapon dew. Free electron laser continuous phase space high gain theory microbunching fel gain low gain theory longitudinal equation of motion. Free electron laser fel a due to oscillation in undulator field, electron velocity receives transverse component parallel to electric field vector of e. Free electron laser a motivation and introduction c experimental realization challenges b theoretical approach. 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 heart of fel is so called undulator or wiggler a magnetic structure, creating spacealternating but constant in time magnetic field see fig. Freeelectron laser continuous phase space high gain theory microbunching fel gain low gain theory longitudinal equation of motion. Today such lasers are used for research in materials science, chemical technology, biophysical. Simulation of laserelectron beam interaction in the optical. From the general concept, several free electron laser con.
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. Research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described. 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. Novel electron accelerator techniques can be used to create free electron lasers in a wide wave length interval extending to the xray region, i. Colson w b 1990 classical free electron laser theory laser handbook vol 6, ed w b colson et al. The center for freeelectron 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 the three partners join forces to explore structural changes of atoms, molecules, condensed, biological, or warm dense matter on. A simplified description of xray freeelectron lasers. Physics of the freeelectron laser lasers, photonics, and.
Atomic selectrons are delocalised due to overlap of outer orbits. Introduction to free electron lasers and fourthgeneration. Sasefreeelectron laser short pulse sasefreeelectron laser wavelength range, nm 10. Each electron emits a wave train with n u cycles 1n u n u. Fels based on jefferson labs superconducting electronaccelerating technology are being developed to process plastics. Free electron lasers lecture i brian mcneil, university of strathclyde, glasgow, scotland. Radiation from an oscillating electric charge consider a single oscillating electron. Physics of the freeelectron 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. Fels based on jefferson labs superconducting electronaccelerating technology are being developed to process plastics, synthetic fibers, advanced materials, and metals as. The essential features of the theory of the free electron laser fel are given in some detail. The free electron laser fel will be an outstanding tool for research and industrial application.
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. Because of the wavelength scaling, the freeelectron laser is capable of producing very high. Laser mode laser field laser action free electron laser moving frame these keywords were added by machine and not by the authors. The light is emitted as the electron beam bunches into many very thin. On the theory of the free electron laser springerlink. Today such lasers are used for research in materials science, chemical technology, biophysical science, medical applications, surface studies, and solidstate physics. The laser is a device which is today used in a wide list of fields. Physics of the freeelectron laser the freeelectron laser can produce intense, coherent light as the result of the interaction between an electron beam and an electric field of light. Rp photonics encyclopedia free electron lasers, fel. 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. A free electron laser is a generator of tunable, coherent, high power radiation from millimeter through ultraviolet wavelengths.
In 1998 he joined the faculty of the university of hawaii where he is currently an associate professor of physics. The inverse free electron laser experiment at the neptune laboratory at ucla accelerated electrons from 14. Free electron laser page of the world wide web virtual library this is a collection of web resources. A free electron laser consists of an electron beam propagating through a periodic magnetic field. Electron free electron laser laser wavelength range, nm 10. 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. The free electron laser fel is a natural alternative as a radiation source national research council, 1982. The optical resonator with macroscopic dimensions that could store significant optical power at short wavelengths was crucial to the invention of the 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.
Electron freeelectron laser laser wavelength range, nm 10. 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. The analytical theory of the phasemerging effect and the physical. So we can write the full quantum state of the electron as follows. The wiggler and the radiation combine to produce a beat wave, which is essentially an interference. Pdf a freeelectron laser consists of an electron beam propagating through a periodic magnetic field. Synchrotron radiation sources and free electron lasers. Introduction to free electron lasers the nature of light gaussian beam laser beam emittance. A new spectrum of opportunities for manufacturing and for basic research. To maintain the resonant condition with the accelerating.
A free electron laser fel is a linear accelerator that is designed to produce very fast bursts of light with extremely high peak brightness. How a quantum laser works an external source of energy excites electrons from the ground state to an. Choosing the required parameters laser resonators for fels fel output characteristics fel vs conventional laser current trends. Lectures on the free electron laser theory and related topics g. For a certain combination of parameters, this effect is stationary. Experimental and numerical studies of the inverse free electron laser using a gwlevel 10.
Relativistic electron beam magnetic field laser beam following section describes interaction of the electron beam with either magnetic field, laser beam or both references. Introduction to freeelectron lasers the nature of light gaussian beam laser beam emittance. Lectures on the free electron laser theory and related. In particular, this code has been used to simulate the laser electron beam interaction in an optical klystron. 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. A short introduction to free electron lasers andy wolski the cockcroft institute, and the university of liverpool, uk. Freeelectron lasers which are also called ubitrons when applied to microwaves millimeter waves consist of an electron beam propagating through a periodic transverse magnetic field called a wiggler or undulator that induces motion perpendicular to the axis of symmetry. A free electron laser is a relatively exotic type of laser where the optical amplification is achieved in an undulator, fed with high energy relativistic electrons from an electron accelerator. Freeelectron laser fel a due to oscillation in undulator field, electron velocity receives transverse component parallel to electric field vector of e. 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. Introduction to freeelectron lasers neil thompson astec. Free electron lasers are very ixible sources of coherent radiation. Free electron lasers an overview sciencedirect topics. A motivation and introduction b theoretical approach c.
Free electron lasers with higher average power and shorter wavelengths are under development. A free electron laser fel operating in the quantum regime can provide a compact and monochromatic xray source. Jefferson labs freeelectron laser is the worlds highestpower tunable infrared laser and was developed using the labs expertise in superconducting radiofrequency srf accelerators. Pelligrini, introduction to the physics of the free electron laser, laser handbook, vol. Free electron lasers 2002 proceedings of the 24th international free electron laser conference and the 9th fel users workshop, argonne, illinois, u. Pdf with intensities 1081010 times greater than other laboratory sources, x ray.
Properties and prospects1 gunnar ingelman and kai siegbahn uppsala university abstract. Simulation of laserelectron beam interaction in the. The freeelectron laser fel principle has been known since the early 1970s. In a fel the optical amplification takes place in an undulator which is fed with high energy electrons from an electron. Theory and practice of free electron lasers particle accelerator school day 1 dinh nguyen, steven russell. 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 effects on ifel acceleration with respect to the variation of the laser electric field, the input.
Beginning with an explanation of the basic gain mechanism, the lectures continue with a discussion. Freeelectron laser fel is a unique laser technology, enabling creation of tunable highpower sources. The fel also provides ultraviolet laser light, including vacuum ultraviolet light, and is also a source of terahertz light. 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 practice of freeelectron lasers particle accelerator school day 1 dinh nguyen, steven russell. Freeelectron lasers fels have operated over virtually the entire electromagnetic spectrum from microwaves through the ultraviolet and up to average power levels of 2 kw. Due to the coherent emission, very large intensities.
State of the art xray free electron laser facilities currently provide the brightest xray pulses available, typically with mj energy and several hundred femtosecond duration. Sase free electron laser short pulse sase free electron laser wavelength range, nm 10. Pdf an introduction to the theory of free electron lasers. Highpower freeelectron lasers technology and future. Flash the freeelectron laser in hamburg desy flash. A freeelectron laser fel operating in the quantum regime can provide a compact and monochromatic xray source. This process is experimental and the keywords may be updated as the learning algorithm improves. Successful freeelectron based light sources can be developed along the the lines described by einstein, schawlow and townes based solely on transition rates the con. Freeelectron lasers fels offer substantial cost and capability advantages including advantages for highvolume materials processing over other manufacturing tools. The classical theory of fels is an extension of the theory of the ubitron developed by phillips 3, 4. Phasemerging enhanced harmonic generation freeelectron. The free electron lasers fels was invented by by j.
Freeelectron lasers with higher average power and shorter wavelengths are. Free electron laser fel theory is extended to explain several effects associated with high. The power radiated by a single electron interacting with the laser beam is 0 2 0 2 21. Basic physical processes and principles of free electron.
At the first glance, this phasemerging phenomenon is very similar with the electron beam energy spread cooling. Microbunching as a result of the interaction of the electron bunch with an electromagnetic pulse is. In the field of freeelectron lasers fels, however, classical physics is sufficient to. Laser is an acronim for light amplification by stimulated emission of radiation. Classical theory of freeelectron lasers book iopscience. Fels make some of the most brilliant light sources ever made by humankind.
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