Novel electron accelerator techniques can be used to create free electron lasers in. A freeelectron laser consists of an electron beam propagating through a periodic magnetic field. 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. Freeelectron lasers driven by laser plasma accelerators. Introduction the use of lasers for material processing was recognized fairly early, but their. Twocolor freeelectron laser via two orthogonal undulators. The first two techniques are able to produce radiation pulses in the femtosecond time domain and in the soft x. Free electron lasers fels have been built ranging in wavelength from longwavelength oscillators using partial wave guiding through ultraviolet through hard xray that are either seeded or start from noise sase. Among the different possible gain media, the free electron lasers fel uses free electrons in the period permanent magnetic field of an undulator, covering wavelengths from far infra red to xray. High harmonic generation in the undulators for free electron. High averagepower freeelectron lasers may be useful for pumping high peakpower solidstate laseramplifiers.
Synchrotron radiation sources and free electron lasers. 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. Whereas an undulator alone would cause the electrons to radiate. High averagepower free electron lasers may be useful for pumping high peakpower solidstate laseramplifiers. 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.
In the case of free electron lasers the time average brightness should increase from 10 19 aps undulator a to 10 26 tesla, figure 2. 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. 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. The wavelengths of two dierent colors can be changed by. In modern highgain freeelectron lasers, ultrafast photon pulses designed for. Freeelectron lasers sources for scientific applications. Freeelectron lasers as pumps for highenergy solidstate lasers. The effects on ifel acceleration with respect to the variation of the laser electric field, the input.
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. Read scientific assessment of highpower freeelectron. Freeelectron lasers as pumps for highenergy solidstate. We present an introduction to the operating principles of freeelectron lasers, discussing the amplification process, and the requirements on the electron beam necessary to achieve desired performance. Freeelectron lasers sources for scientific applications m. Freeelectron laser wikipedia, the free encyclopedia.
Freeelectron lasers oscillators we can achieve coherence through lowgain operation and a cavity, as in a traditional laser can use low energy e beams to make visiblemicrowave radiation requires re. Pdf a freeelectron laser consists of an electron beam propagating through a periodic magnetic field. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. Towards a free electron laser based on laser plasma. The underlying principle of the intense pulses from the xray laser liesin the principle of self amplified spontaneous emission sase, which leads to the microbunching. 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.
We can now obtain accurate results, accounting for a variety of losses. Freeelectron laser, high average power laser, materials processing, ultrafast lasers 1. At very high peakpowers, the pump source for solidstate lasers is nontrivial. Lasers, freeelectron 3 undulator electron beam optical cavity mirror partial mirror radiation field outcoupled field fig. Pdf twocolor freeelectron laser with two orthogonal. For the planar undulators above a period of 45mm was chosen to enable tuning over the photon energy range 10100ev. High harmonic generation in the undulators for free. The fel also provides ultraviolet laser light, including vacuum ultraviolet light, and is also a source of terahertz light. May 25, 2017 the results of theoretical examination and comparative analysis of synchrotron radiation sources specifically, undulators and xray free electron lasers fels are presented. The advantages and disadvantages of single pass and of multipass designs are. 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. The undulators tuning the fel is achieved by varying the undulator gap and by changing the electron beam energy between 750950mev.
Threedimensional, timedependent simulation of freeelectron. Physics of the freeelectron laser lasers, photonics, and. Rp photonics encyclopedia free electron lasers, fel. 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. The physics and properties of free electron lasers samuel krinsky brookhaven national laboratory, upton, ny 11973 abstract. Electron injectors chapter chapter chapter chapter chapter chapter chapter. Particle accelerator school august 112, 1988 are presented. The problem of generation of shorter radiation pulses is prioritized. The free electron laser fel uses a high quality relativistic beam of electrons passing. We present an introduction to the operating principles of freeelectron. Ort ga lure, b timent 209 d, universit paris sud, 91405 orsay cedex, france abstract. Even with lpa energy spreads typically at the percent level, the ebeam brightness can be excellent, due to the low normalized emittance free electron laser xfel at stanford university. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of terahertz radiation sources and upcoming brilliant light sources driven by laserplasma accelerators. Phasemerging enhanced harmonic generation freeelectron.
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. A simplified description of xray freeelectron lasers. Different form the standardhghg, a transverse gradient undulator. In addition, fels that produce different polarizations of the output radiation ranging from linear through elliptic to. Experimental and numerical studies of the inverse free electron laser using a gwlevel 10. It can have the optical properties characteristic of conventional lasers such as high spatial coherence and a near diffraction limited radiation beam. Undulators for short pulse xray selfamplified spontaneous. Basic physical processes and principles of free electron lasers fels dagnachew w. The synchrotron radiation of relativistic electrons in undulator magnets and the.
For the planar undulators above a period of 45mm was chosen to. These reduce both the undulator length to centimeters and the electron energy e. Free electron laser fel theory is extended to explain several effects associated with high. The peak undulator field strength is usually several kg and can be constructed. High average power freeelectron lasers a new laser. Workie department of physics university of cincinnati cincinnati, ohio 45221 november 26, 01 abstract a. Among the different possible gain media, the free electron lasers fel uses free electrons in the period permanent magnetic field of an undulator, covering wavelengths from far infra. Freeelectron laser an overview sciencedirect topics. It can have the optical properties characteristic of conventional lasers such as. Properties and prospects1 gunnar ingelman and kai siegbahn uppsala university abstract. Their development received a strong impetus from radar development during world war ii. Laserplasma accelerators lpas have the potential to drive compact freeelectron lasers fels.
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. Discusses basic physical concepts, along with detailed derivations of the relevant particle dynamics for both. Main fel schemes, useful for generation of high frequency radiation, extending to xrays, are presented. Phasemerging enhanced harmonic generation freeelectron laser chao feng, haixiao deng 1, dong wang, and zhentang zhao shanghai institute of applied physics, chinese academy of sciences. These tubes are still successful and useful sources of coherent radiation with wavelengths ranging from. Even with lpa energy spreads typically at the percent level, the ebeam brightness can be excellent, due to. The theory of synchrotron radiation and of the free electron laser, design examples and the technology basis are presented. Proposal for an xray free electron laser oscillator arxiv. Basic physical processes and principles of free electron.
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. Indeed, for the double frequency undulator with n150 periods, k2, h5, d0. Provides a complete and comprehensive discussion of the physics of freeelectron lasers. Jefferson labs freeelectron laser is the worlds highestpower tunable infrared laser and was developed using the labs expertise in superconducting radiofrequency srf accelerators. Freeelectron lasers fels have been built ranging in wavelength from longwavelength oscillators using partial wave guiding through ultraviolet through hard xray that are either seeded or. The freeelectron laser ofelo has proven to be an invaluable source of radiation in the uv to far infrared spectral ranges. An ampli er free electron laser fel including two orthogonal polarized undulators with dierent periods and eld intensities is able to emit two color radiations with different frequency and polarization while. In later developments, stemming from this, single pass gain of circularly polarized radiation was experimentally demonstrated by means of a twister structure and an optical cavity, obtained by adding mirrors to the magnet assembly, was used to achieve buildup of the radiation in an oscillator device known as the freeelectron laser. The ucsb free electron lasers provide tunable, coherent, kilowatt level radiation for scientific research in the far infrared portion of the spectrum 2. The undulator shown is a permanentmagnet planar undulator. Peak brilliance of xray fels and undulators for spontaneous.
We discuss a twocolor selfamplified spontaneous emission freeelectron laser fel amplifier where the emission is obtained from two orthogonally polarized undulators with different periods and field intensities. Due to the coherent emission, very large intensities. Undulators and generation of xray pulses in freeelectron. The results of theoretical examination and comparative analysis of synchrotron radiation sources specifically, undulators and xray freeelectron lasers fels are presented. Introduction to free electron lasers and fourthgeneration. An ampli er free electron laser fel including two orthogonal polarized undulators with dierent periods and eld intensities is able to emit two color radiations with different frequency and polarization while the total length of device does not change respect to usual single color fels. 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.
The first sources of powerful coherent radiation were the microwave tubes invented earlier in this century. Laur 0901205 12 us particle acceus particle accelerator school. 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. Novel electron accelerator techniques can be used to create free electron lasers in a wide wave length interval extending to the xray region, i. Optical undulators for free electron lasers james lawler, joseph bisognano, robert bosch, michael green, kenneth jacobs, deniz yavuz, univ of wisconsin, madison free electron lasers fels in the xray region are opening new research directions in amo physics and other. The light is emitted as the electron beam bunches into many very thin. Relation to scientific free electron lasers the scientific opportunities presented by free electron lasers and other advanced coherent light sources were studied in a 1994 report by the committee on free electron lasers and other advanced coherent light sources, organized by the board on chemical sciences and technology and the board on physics. Xray sources modern high intensity sources are based on synchrotron radiation from high energy electrons propagating through an undulator this talk will. 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. Threedimensional, timedependent simulation of free. The underlying principle of the intense pulses from the xray laser liesin the principle of self amplified spontaneous emission sase, which leads to the. Free electron lasers are laser devices where light amplification occurs by interaction with fast electrons in an undulator. Read scientific assessment of highpower freeelectron laser. 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.
The electrons are bound to atomic, molecular or solidstate levels, so one may call this a. A free electron laser generates tunable, coherent, high power radiation, currently spanning wavelengths from millimeter to xray. Pelligrini, introduction to the physics of the free electron laser, laser handbook, vol. Today such lasers are used for research in materials science, chemical technology, biophysical science, medical applications, surface studies, and solidstate physics. A freeelectron laser fel is a kind of laser whose lasing medium consists of veryhighspeed. The handbook presents advanced concepts like seeding and harmonic. More importantly, the peak brightness, which is a key parameter for many laser applications, leaps from 10 2225 with present thirdgeneration source undulators to 10 34 at tesla. In this paper the physical process of new type of coherent. Relation to scientific freeelectron lasers the scientific opportunities presented by freeelectron lasers and other advanced coherent light sources were studied in a 1994 report by the committee on. Apr 24, 2015 among the different possible gain media, the free electron lasers fel uses free electrons in the period permanent magnetic field of an undulator, covering wavelengths from far infra red to xray. The freeelectron laser fel principle has been known since the early. Phasemerging enhanced harmonic generation freeelectron laser.
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