Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 ± 50 MeV quasi-monoenergetic electrons with a divergence of [Delta][theta] = 2.85 ± 0.15 mRad. While maintaining a nearly constant plasma density (3 x 1018 cm−3), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr}> 4 and saturates around 100 pC for P/P{sub cr}> 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.
Measurements of the Critical Power for Self-injection of Electrons in a Laser Wakefield Accelerator
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 ± 50 MeV quasi-monoenergetic electrons with a divergence of [Delta][theta] = 2.85 ± 0.15 mRad. While maintaining a nearly constant plasma density (3 x 1018 cm−3), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr}> 4 and saturates around 100 pC for P/P{sub cr}> 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 ± 50 MeV quasi-monoenergetic electrons with a divergence of [Delta][theta] = 2.85 ± 0.15 mRad. While maintaining a nearly constant plasma density (3 x 1018 cm−3), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr}> 4 and saturates around 100 pC for P/P{sub cr}> 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.
Free Electron Lasers
Author: Sandor Varro
Publisher: BoD – Books on Demand
ISBN: 9535102796
Category : Technology & Engineering
Languages : en
Pages : 263
Book Description
Free Electron Lasers consists of 10 chapters, which refer to fundamentals and design of various free electron laser systems, from the infrared to the xuv wavelength regimes. In addition to making a comparison with conventional lasers, a couple of special topics concerning near-field and cavity electrodynamics, compact and table-top arrangements and strong radiation induced exotic states of matter are analyzed as well. The control and diagnostics of such devices and radiation safety issues are also discussed. Free Electron Lasers provides a selection of research results on these special sources of radiation, concerning basic principles, applications and some interesting new ideas of current interest.
Publisher: BoD – Books on Demand
ISBN: 9535102796
Category : Technology & Engineering
Languages : en
Pages : 263
Book Description
Free Electron Lasers consists of 10 chapters, which refer to fundamentals and design of various free electron laser systems, from the infrared to the xuv wavelength regimes. In addition to making a comparison with conventional lasers, a couple of special topics concerning near-field and cavity electrodynamics, compact and table-top arrangements and strong radiation induced exotic states of matter are analyzed as well. The control and diagnostics of such devices and radiation safety issues are also discussed. Free Electron Lasers provides a selection of research results on these special sources of radiation, concerning basic principles, applications and some interesting new ideas of current interest.
Accelerator Physics
Author: Ishaq Ahmad
Publisher: BoD – Books on Demand
ISBN: 9535138359
Category : Science
Languages : en
Pages : 209
Book Description
Scientists are continuously improving the accelerator and light source technologies to observe the secret of matter as well as the origin of nature which create new opportunities for accelerator physics research. This book provides a glance view on phase space dynamics of electron beam, motion of relativistic electrons in three-dimensional ideal undulator magnetic field, numerical simulation of electron multi-beam linear accelerator EVT, nuclear safety design of high energy accelerator facilities, and radiation safety aspects of operation of electron linear accelerators. The determination of the structure of biomolecules is presently among the best examples of the application of synchrotron radiation. This book also covers synchrotron-based X-ray diffraction study of mammalian connective tissues and related disease. Furthermore, an overview of the versatile applications of ion beam and synchrotron radiation techniques in hair elemental profiling in biomedical studies is also incorporated in this book.
Publisher: BoD – Books on Demand
ISBN: 9535138359
Category : Science
Languages : en
Pages : 209
Book Description
Scientists are continuously improving the accelerator and light source technologies to observe the secret of matter as well as the origin of nature which create new opportunities for accelerator physics research. This book provides a glance view on phase space dynamics of electron beam, motion of relativistic electrons in three-dimensional ideal undulator magnetic field, numerical simulation of electron multi-beam linear accelerator EVT, nuclear safety design of high energy accelerator facilities, and radiation safety aspects of operation of electron linear accelerators. The determination of the structure of biomolecules is presently among the best examples of the application of synchrotron radiation. This book also covers synchrotron-based X-ray diffraction study of mammalian connective tissues and related disease. Furthermore, an overview of the versatile applications of ion beam and synchrotron radiation techniques in hair elemental profiling in biomedical studies is also incorporated in this book.
Self Injection and Radiation Production in Laser Wakefield Accelerators
Author: Matthew Philip Tooley
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The laser wakefield accelerator (LWFA) is a nascent electron acceleration technology characterised by extremely large (100s GV/m) accelerating fields and compact (~ cm) scale. Self-injection is a key mechanism in the production of electron beams from the laser wakefield accelerator (LWFA), where background plasma electrons spontaneously enter the accelerating field region. Self-injection is routinely exploited but a fully self-consistent model for the process is still lacking,as are reliable methods for the control of the self-injection process. In this thesis a model for control of self-injection using plasma density gradients or laser intensity evolution is presented. The model is validated using particle-in-cell (PIC) simulations and injection of sub-femtosecond electron bunches is demonstrated. This control is further exploited to demonstrate injection of a train of multiple electron bunches into the LWFA.An additional characteristic of the LWFA is the strong transverse focusing fields, which cause electrons to undergo betatron motion and emit broadband XUV and X-ray radiation. The previously demonstrated bunching is investigated as a source of tuneable coherent emission. Analytic and numerical models demonstrate coherent enhancement at the bunching wavelength. Finally the stability of the scheme is considered with respect to energy and spatial bunch spreads and found to be viable for tuneable XUV radiation production with current state of the art LWFA bunch parameters.
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The laser wakefield accelerator (LWFA) is a nascent electron acceleration technology characterised by extremely large (100s GV/m) accelerating fields and compact (~ cm) scale. Self-injection is a key mechanism in the production of electron beams from the laser wakefield accelerator (LWFA), where background plasma electrons spontaneously enter the accelerating field region. Self-injection is routinely exploited but a fully self-consistent model for the process is still lacking,as are reliable methods for the control of the self-injection process. In this thesis a model for control of self-injection using plasma density gradients or laser intensity evolution is presented. The model is validated using particle-in-cell (PIC) simulations and injection of sub-femtosecond electron bunches is demonstrated. This control is further exploited to demonstrate injection of a train of multiple electron bunches into the LWFA.An additional characteristic of the LWFA is the strong transverse focusing fields, which cause electrons to undergo betatron motion and emit broadband XUV and X-ray radiation. The previously demonstrated bunching is investigated as a source of tuneable coherent emission. Analytic and numerical models demonstrate coherent enhancement at the bunching wavelength. Finally the stability of the scheme is considered with respect to energy and spatial bunch spreads and found to be viable for tuneable XUV radiation production with current state of the art LWFA bunch parameters.
LASER WAKEFIELD ACCELERATION BEYOND 1 GeV USING IONIZATION INDUCED INJECTION*
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Book Description
A series of laser wake field accelerator experiments leading to electron energy exceeding 1 GeV are described. Theoretical concepts and experimental methods developed while conducting experiments using the 10 TW Ti:Sapphire laser at UCLA were implemented and transferred successfully to the 100 TW Callisto Laser System at the Jupiter Laser Facility at LLNL. To reach electron energies greater than 1 GeV with current laser systems, it is necessary to inject and trap electrons into the wake and to guide the laser for more than 1 cm of plasma. Using the 10 TW laser, the physics of self-guiding and the limitations in regards to pump depletion over cm-scale plasmas were demonstrated. Furthermore, a novel injection mechanism was explored which allows injection by ionization at conditions necessary for generating electron energies greater than a GeV. The 10 TW results were followed by self-guiding at the 100 TW scale over cm plasma lengths. The energy of the self-injected electrons, at 3 x 1018 cm−3 plasma density, was limited by dephasing to 720 MeV. Implementation of ionization injection allowed extending the acceleration well beyond a centimeter and 1.4 GeV electrons were measured.
Publisher:
ISBN:
Category :
Languages : en
Pages : 7
Book Description
A series of laser wake field accelerator experiments leading to electron energy exceeding 1 GeV are described. Theoretical concepts and experimental methods developed while conducting experiments using the 10 TW Ti:Sapphire laser at UCLA were implemented and transferred successfully to the 100 TW Callisto Laser System at the Jupiter Laser Facility at LLNL. To reach electron energies greater than 1 GeV with current laser systems, it is necessary to inject and trap electrons into the wake and to guide the laser for more than 1 cm of plasma. Using the 10 TW laser, the physics of self-guiding and the limitations in regards to pump depletion over cm-scale plasmas were demonstrated. Furthermore, a novel injection mechanism was explored which allows injection by ionization at conditions necessary for generating electron energies greater than a GeV. The 10 TW results were followed by self-guiding at the 100 TW scale over cm plasma lengths. The energy of the self-injected electrons, at 3 x 1018 cm−3 plasma density, was limited by dephasing to 720 MeV. Implementation of ionization injection allowed extending the acceleration well beyond a centimeter and 1.4 GeV electrons were measured.
An Exploration on Electron Bunching of Ionization Induced Self-injection in Laser Wakefield Accelerators
Author: Deyun Li (M.A.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 84
Book Description
Plasma-based wakefield accelerator is attractive for generating quasi-monoenergetic electron beams using the bubble regime. The bubble is formed by an intense driver, which propagates through the plasma and expels all electrons transversely, creating a cavity free of cold plasma electrons that trailing behind the driver. Self-injection is applicable in the bubble regime, which can produce bunches of quasi-monoenergetic electrons. (1) Such electron bunching structure can be diagnosed with coherent transition radiation and may be exploited to generate powerful high frequency radiation [16].This thesis focuses on electron bunching phenomenon through WAKE simulations and theoretical analysis. The simulation is completed under laser-driven field ionization wakefield acceleration. The code is improved by taking into consideration the high frequency property of laser driver in wakefield acceleration. Finer grid size is introduced to the ionization injection part of WAKE, for increasing simulation accuracy without much sacrifice of programming efficiency. Various conditions for optimal bunching in the trapped electrons are explored computationally and analytically.
Publisher:
ISBN:
Category :
Languages : en
Pages : 84
Book Description
Plasma-based wakefield accelerator is attractive for generating quasi-monoenergetic electron beams using the bubble regime. The bubble is formed by an intense driver, which propagates through the plasma and expels all electrons transversely, creating a cavity free of cold plasma electrons that trailing behind the driver. Self-injection is applicable in the bubble regime, which can produce bunches of quasi-monoenergetic electrons. (1) Such electron bunching structure can be diagnosed with coherent transition radiation and may be exploited to generate powerful high frequency radiation [16].This thesis focuses on electron bunching phenomenon through WAKE simulations and theoretical analysis. The simulation is completed under laser-driven field ionization wakefield acceleration. The code is improved by taking into consideration the high frequency property of laser driver in wakefield acceleration. Finer grid size is introduced to the ionization injection part of WAKE, for increasing simulation accuracy without much sacrifice of programming efficiency. Various conditions for optimal bunching in the trapped electrons are explored computationally and analytically.
Laser Wakefield Electron Acceleration
Author: Karl Schmid
Publisher: Springer Science & Business Media
ISBN: 364219950X
Category : Science
Languages : en
Pages : 169
Book Description
This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams.
Publisher: Springer Science & Business Media
ISBN: 364219950X
Category : Science
Languages : en
Pages : 169
Book Description
This thesis covers the few-cycle laser-driven acceleration of electrons in a laser-generated plasma. This process, known as laser wakefield acceleration (LWFA), relies on strongly driven plasma waves for the generation of accelerating gradients in the vicinity of several 100 GV/m, a value four orders of magnitude larger than that attainable by conventional accelerators. This thesis demonstrates that laser pulses with an ultrashort duration of 8 fs and a peak power of 6 TW allow the production of electron energies up to 50 MeV via LWFA. The special properties of laser accelerated electron pulses, namely the ultrashort pulse duration, the high brilliance, and the high charge density, open up new possibilities in many applications of these electron beams.
Laser Wakefield Acceleration at Reduced Density in the Self-Guided Regime
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 13
Book Description
Experiments conducted using a 200TW 60 fs laser have demonstrated up to 720 MeV electrons in the self-guided laser wakefield regime using pure Helium gas jet targets. Charge and energy of the accelerated electrons was measured using an electron spectrometer with a 0.5T magnet and charge callibrated image plates. The self-trapped charge in a helium plasma was shown to fall off with decreasing electron density with a threshold at 2.5 x 1018 (cm−3) below which no charge is trapped. Self-guiding however is shown to continue below this density limitation over distances of 14 mm with an exit spot size of 25[mu]m. Simulations show that injection of electrons at these densities can be assisted through ionization induced trapping in a mix of Helium with 3% Oxygen.
Publisher:
ISBN:
Category :
Languages : en
Pages : 13
Book Description
Experiments conducted using a 200TW 60 fs laser have demonstrated up to 720 MeV electrons in the self-guided laser wakefield regime using pure Helium gas jet targets. Charge and energy of the accelerated electrons was measured using an electron spectrometer with a 0.5T magnet and charge callibrated image plates. The self-trapped charge in a helium plasma was shown to fall off with decreasing electron density with a threshold at 2.5 x 1018 (cm−3) below which no charge is trapped. Self-guiding however is shown to continue below this density limitation over distances of 14 mm with an exit spot size of 25[mu]m. Simulations show that injection of electrons at these densities can be assisted through ionization induced trapping in a mix of Helium with 3% Oxygen.
Laser-plasma Electron Accelerators and Nonlinear, Relativistic Optics
Author: Robert Loren Wagner
Publisher:
ISBN:
Category :
Languages : en
Pages : 488
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 488
Book Description
Laser Triggered Injection of Electrons in a Laser Wakefield Accelerator with the Colliding Pulse Method
Author: C. B. Schroeder
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
An injection scheme for a laser wakefield accelerator that employs a counter propagating laser (colliding with the drive laser pulse, used to generate a plasma wake) is discussed. The threshold laser intensity for electron injection into the wakefield was analyzed using a heuristic model based on phase-space island overlap. Analysis shows that the injection can be performed using modest counter propagating laser intensity a{sub 1}
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
An injection scheme for a laser wakefield accelerator that employs a counter propagating laser (colliding with the drive laser pulse, used to generate a plasma wake) is discussed. The threshold laser intensity for electron injection into the wakefield was analyzed using a heuristic model based on phase-space island overlap. Analysis shows that the injection can be performed using modest counter propagating laser intensity a{sub 1}