We report the first experimental results on a highgain harmonicgeneration hghg free electron laser fel operating in the ultraviolet. 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. The fel also provides ultraviolet laser light, including vacuum ultraviolet light, and is also a source of terahertz light. Thus, the emitted wavelength in the electron reference frame is l.
The upgraded jlab free electron laser fel is online as a wavelengthtunable, subpicosecond, 10 kw infrared light source offering a combination of high repetition rate and high power per pulse. 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. Due to the coherent emission, very large intensities. Laser europeen a electrons libres et a rayons x wikipedia. The free electron laser fel will be an outstanding tool for research and industrial application. The free electron laser felix at the radboud university, nijmegen, netherlands. We report the first experimental results on a highgain harmonicgeneration hghg freeelectron laser fel operating in the ultraviolet. Fels were developed from the work on free electron beams. 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. Novel electron accelerator techniques can be used to create free electron lasers in a wide wave length interval extending to the xray region, i. Also compare the wavelengths associated with these two particles. How do we ensure continuous energy transfer over length of undulator.
History of freeelectron laser fel the fel is the result of many years of theoretical and experimental work on the generation of radiation from relativistic electron beams. 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. Metastable means that the electron will hang around for a little while before going back to the ground state. Le laser europeen a electrons libres et a rayons x anglais. The optical resonator with macroscopic dimensions that could store significant optical power at short wavelengths was crucial to the invention of the laser. The light is emitted as the electron beam bunches into many very thin. Motz showed in 1951 that an electron beam propagating through an undulator magnet.
Jun 18, 2014 compare the minimum uncertainty in the positions of a baseball mass 140 gm and an electron, each with a speed of 91. 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. Basic physical processes and principles of free electron. The freeelectron laser felix at the radboud university, nijmegen, netherlands. 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. Laser dans lequel lemission laser provient du rayonnement synchrotron dun faisceau delectrons acceleres.
A simplified description of xray freeelectron lasers. The jlab fel operates in regimes unattainable by subpicosecond tabletop lasers, even at a specific wavelength. The freeelectron laser is tunable and has the widest frequency range of any laser. Introduction to free electron lasers and fourthgeneration. Definition laser a electrons libres lel futura sciences. However, seen in the laboratory reference frame fig. Synchrotron radiation sources and free electron lasers. The upgraded jlab freeelectron laser fel is online as a wavelengthtunable, subpicosecond, 10 kw infrared light source offering a combination of high repetition rate and high power per pulse. Compare the minimum uncertainty in the positions of a baseball mass 140 gm and an electron, each with a speed of 91. In this paper the physical process of new type of coherent. A freeelectron laser consists of an electron beam propagating through a periodic magnetic field. When a photon of energy disturbs an electron in a metastable state figure \\pageindex1\, the electron drops to the lowerenergy level and emits an addition photon, and the two photons proceed off together.
In most cases, the electron is in an unstable state, and it will quickly move to a lower state. 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. Laser material has to have a metastable state corresponding to a useful energy. The active medium is a collection of atoms, or molecules that can undergo stimulated emission.
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. Laser light is produced by an active medium, or gain medium inside the laser optical cavity. Highresolution laser spectroscopy chemistry libretexts. 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 free electron laser fel is a natural alternative as a radiation source national research council, 1982. Firstly, the scattering of an electron by a potential in the presence of a laser field is considered. Jefferson labs freeelectron laser is the worlds highestpower tunable infrared laser and was developed using the labs expertise in superconducting radiofrequency srf accelerators.
Ce projet est europeen et international avec 12 pays participants. The free electron laser is tunable and has the widest frequency range of any laser. Today such lasers are used for research in materials science, chemical technology, biophysical. This wave causes the electron to oscillate and to emit waves of equal wavelength. A free electron laser consists of an electron beam propagating through a periodic magnetic field. The periodic undulator magnetic field produces a transverse component of the electron velocity that. Lasers a electrons libres, principe du laser a electrons. Laser operation and components chemistry libretexts. Session cookies created by the elettrasincrotrone trieste s. The process of light stimulated emission is fundamental to laser operation. Free electron lasers are laser devices where light amplification occurs by interaction with fast electrons in an undulator.
An incident photon of frequency f causes a cascade of photons of the same frequency. The electron, therefore, sees the undulator as an electromagnetic wave fig. The fel 5 is based on a resonant interaction between an electromagnetic wave and an electron beam traveling along the axis of an undulator magnet. Rp photonics encyclopedia free electron lasers, fel. Le premier jet laser a ete produit en mai 2017 2, 3, les operations nominales debutant en septembre 2017 4. Basic physical processes and principles of free electron lasers fels dagnachew w. Properties and prospects1 gunnar ingelman and kai siegbahn uppsala university abstract. The wiggler induces transverse sinusoidal velocity in electron beam energy exchange occurs between the transverse electron current and transverse electric field of a copropagating light beam depending on the phase of the light beam with the electrons wiggling motion, some electrons gain energy while others lose energy energy modulation. 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. How fibre lasers work optoelectronics research centre.
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