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Toward Creating a Coherent, Next-Generation Light Source with special emphasis on nonlinear harmonic generation in single-pass, high-gain free-electron lasers

Biedron, Sandra G. LU (2001)
Abstract (Swedish)
Popular Abstract in Swedish

De mest briljanta ljuskällor som finns idag är de så kallade synkrotronljuskällorna som kan generera ljus över ett mycket brett våglängdsspectrum, från synligt ljus ända till mycket korta våglängder - röntgenstrålar. Det existerar många sådana faciliteter runt om i världen och de används dagligen i olika experiment för att öka våra kunskaper om material på en mikrospopisk nivå inom ett flertal forskningsområden relaterade till fysik, biologi och kemi.



Fastän dessa källor är väldigt ljusstarka, kräver en del experiment i framtiden ännu intensivare ljus som dessutom har laserliknande egenskaper med en varierbar våglängd - ner till röntgenvåglängder. Det pågår därför runt om i... (More)
Popular Abstract in Swedish

De mest briljanta ljuskällor som finns idag är de så kallade synkrotronljuskällorna som kan generera ljus över ett mycket brett våglängdsspectrum, från synligt ljus ända till mycket korta våglängder - röntgenstrålar. Det existerar många sådana faciliteter runt om i världen och de används dagligen i olika experiment för att öka våra kunskaper om material på en mikrospopisk nivå inom ett flertal forskningsområden relaterade till fysik, biologi och kemi.



Fastän dessa källor är väldigt ljusstarka, kräver en del experiment i framtiden ännu intensivare ljus som dessutom har laserliknande egenskaper med en varierbar våglängd - ner till röntgenvåglängder. Det pågår därför runt om i världen en intensiv forskning för att öka vår förståelse om hur en sådan ljuskälla ska kunna byggas. Detta arbete undersöker denna nya typ av ljuskälla.



I det här arbetet rapporterar vi om både teori och experiment och diskuterar också resultat från datorsimuleringar. Vi beskriver också hur en sådan ljuskälla kan byggas i praktiken. Vi har dragit nytta av kunskaper från många ämnesområden inom fysiken, speciellt från teorier om partikelacceleratorer och lasrar. Slutligen presenterar vi hur det är möjligt att använda så kallade högre övertoner av den fundamentala frekvensen för att nå rikigt korta våglängder. (Less)
Abstract
There is a strong desire for short wavelength (~1 Å), short pulsewidth (<100 fs), high-brightness, transverse and longitudinally coherent light pulses for use by the synchrotron radiation community. These requirements exceed the limits achievable by existing, so-called, "third-generation" light sources, such as the Advanced Photon Source (APS) at Argonne National Laboratory (ANL), USA, the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, and SPring-8 in Harima Science Garden City, Japan.



Single-pass, high-gain free-electron laser (FEL) methods have the ability to fulfill these requirements and have been proposed as the next-generation light source. Such arrangements include, but are not limited to,... (More)
There is a strong desire for short wavelength (~1 Å), short pulsewidth (<100 fs), high-brightness, transverse and longitudinally coherent light pulses for use by the synchrotron radiation community. These requirements exceed the limits achievable by existing, so-called, "third-generation" light sources, such as the Advanced Photon Source (APS) at Argonne National Laboratory (ANL), USA, the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, and SPring-8 in Harima Science Garden City, Japan.



Single-pass, high-gain free-electron laser (FEL) methods have the ability to fulfill these requirements and have been proposed as the next-generation light source. Such arrangements include, but are not limited to, straight amplifier configurations, self-amplified spontaneous emission (SASE), the two-undulator harmonic generation amplifier scheme (TUHGS), and high-gain harmonic generation (HGHG). These single-pass, high-gain FELs typically employ planar undulators and can all generate nonlinear spectral harmonics with significant power levels. Of notable interest is the combination of the accelerator and traditional lasers, since existing laser technologies may be used for seeding the amplifier, TUHGS, and HGHG cases.



This work examines single-pass, high-gain free-electron lasers analytically, via numerical simulations, and experimentally. An existing code, MEDUSA, was further developed to simulate relevant mechanisms as will be described. Along with a review of the respective theories, a three-step SASE FEL experiment at the APS, a two-step FEL experiment at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL) involving both the SASE and HGHG methods, and the characteristics of nonlinear harmonic generation in both of these experiments are discussed. Finally, a modular approach to the next-generation light source is described.



The above proof-of-principle experiments represent necessary steps toward achieving the next-generation light source. The ATF experiment tests the SASE and HGHG theories at a mid-infrared wavelength, while the APS experiment examines the SASE theory first at visible and then at ultraviolet wavelengths. The extension from the visible/ultraviolet wavelengths to the x-ray wavelength regime is not trivial, and there still remains much work before achieving the final goal based on the single-pass, high-gain free-electron laser theories and experiments.



Of the topics elucidated within this manuscript, nonlinear harmonic generation in single-pass, high-gain FELs is perhaps the most significant. Although there is a reduction, compared to the fundamental wavelength, in the resultant output photon power when using the nonlinear harmonics to achieve shorter wavelengths, the harmonics do permit the use of an electron bunch of both lower energy and lesser quality. Therefore, smaller, less expensive machines could be developed, allowing many more facilities to be constructed and ultimately benefit from these bright, coherent, next-generation light sources. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Dr Poole, Michael, CLRC Daresbury Laboratory, Warrington, United Kingdom
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Visible and Ultraviolet Sources, Intense Particle Beams and Radiation Sources, Frequency Conversion, Free-Electron Lasers, Harmonic Generation, Physics, Fysik
pages
500 pages
publisher
MAX-lab, Lund University
defense location
Sal B, E-huset
defense date
2001-12-14 13:00
external identifiers
  • Other:ISRN:LUNDTDX
ISBN
91-7874-167-X
language
English
LU publication?
yes
id
a08fe6d0-7c6e-4a1b-967c-a06ff618cd05 (old id 42149)
date added to LUP
2007-10-14 16:27:55
date last changed
2016-09-19 08:45:11
@misc{a08fe6d0-7c6e-4a1b-967c-a06ff618cd05,
  abstract     = {There is a strong desire for short wavelength (~1 Å), short pulsewidth (&lt;100 fs), high-brightness, transverse and longitudinally coherent light pulses for use by the synchrotron radiation community. These requirements exceed the limits achievable by existing, so-called, "third-generation" light sources, such as the Advanced Photon Source (APS) at Argonne National Laboratory (ANL), USA, the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, and SPring-8 in Harima Science Garden City, Japan.<br/><br>
<br/><br>
Single-pass, high-gain free-electron laser (FEL) methods have the ability to fulfill these requirements and have been proposed as the next-generation light source. Such arrangements include, but are not limited to, straight amplifier configurations, self-amplified spontaneous emission (SASE), the two-undulator harmonic generation amplifier scheme (TUHGS), and high-gain harmonic generation (HGHG). These single-pass, high-gain FELs typically employ planar undulators and can all generate nonlinear spectral harmonics with significant power levels. Of notable interest is the combination of the accelerator and traditional lasers, since existing laser technologies may be used for seeding the amplifier, TUHGS, and HGHG cases.<br/><br>
<br/><br>
This work examines single-pass, high-gain free-electron lasers analytically, via numerical simulations, and experimentally. An existing code, MEDUSA, was further developed to simulate relevant mechanisms as will be described. Along with a review of the respective theories, a three-step SASE FEL experiment at the APS, a two-step FEL experiment at the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL) involving both the SASE and HGHG methods, and the characteristics of nonlinear harmonic generation in both of these experiments are discussed. Finally, a modular approach to the next-generation light source is described.<br/><br>
<br/><br>
The above proof-of-principle experiments represent necessary steps toward achieving the next-generation light source. The ATF experiment tests the SASE and HGHG theories at a mid-infrared wavelength, while the APS experiment examines the SASE theory first at visible and then at ultraviolet wavelengths. The extension from the visible/ultraviolet wavelengths to the x-ray wavelength regime is not trivial, and there still remains much work before achieving the final goal based on the single-pass, high-gain free-electron laser theories and experiments.<br/><br>
<br/><br>
Of the topics elucidated within this manuscript, nonlinear harmonic generation in single-pass, high-gain FELs is perhaps the most significant. Although there is a reduction, compared to the fundamental wavelength, in the resultant output photon power when using the nonlinear harmonics to achieve shorter wavelengths, the harmonics do permit the use of an electron bunch of both lower energy and lesser quality. Therefore, smaller, less expensive machines could be developed, allowing many more facilities to be constructed and ultimately benefit from these bright, coherent, next-generation light sources.},
  author       = {Biedron, Sandra G.},
  isbn         = {91-7874-167-X},
  keyword      = {Visible and Ultraviolet Sources,Intense Particle Beams and Radiation Sources,Frequency Conversion,Free-Electron Lasers,Harmonic Generation,Physics,Fysik},
  language     = {eng},
  pages        = {500},
  publisher    = {ARRAY(0xa739980)},
  title        = {Toward Creating a Coherent, Next-Generation Light Source with special emphasis on nonlinear harmonic generation in single-pass, high-gain free-electron lasers},
  year         = {2001},
}