Single-shot Diagnostics of Laser Driven Plasma Accelerators

Single-shot Diagnostics of Laser Driven Plasma Accelerators PDF Author: Yen-Yu Chang
Publisher:
ISBN:
Category :
Languages : en
Pages : 206

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Book Description
We demonstrated single shot diagnostics of laser-plasma accelerators (LPAs). We observed the structure and the evolving process of the blow-out region, the nonlinear waves (plasma bubble) induced by the driving beam using the Faraday rotation diagnostic. We obtained the evolution of the plasma bubble in single shot using Faraday rotation diagnostic with multiple probe beams. The diameter of the bubble changed from 300 [micrometer] to 50 [micrometer] in 2 cm, which revealed the transition of the acceleration stages from ”bubble expanding mode” to ”bubble stabilizing mode”. Moreover, we demonstrated the broad bandwidth frequency domain streak camera (B-FDSC), which can resolve the dynamics of LPAs in single shot. We improved the temporal resolution of B-FDSC to 10 fs by broadening the bandwidth of the probe beam to 100 nm using supercontinuum generation, and we performed a prototype experiment to show that B-FDSC was capable of resolving the evolution of pulse self-steepening and temporal splitting in a single shot.

Single-shot Diagnostics of Laser Driven Plasma Accelerators

Single-shot Diagnostics of Laser Driven Plasma Accelerators PDF Author: Yen-Yu Chang
Publisher:
ISBN:
Category :
Languages : en
Pages : 206

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Book Description
We demonstrated single shot diagnostics of laser-plasma accelerators (LPAs). We observed the structure and the evolving process of the blow-out region, the nonlinear waves (plasma bubble) induced by the driving beam using the Faraday rotation diagnostic. We obtained the evolution of the plasma bubble in single shot using Faraday rotation diagnostic with multiple probe beams. The diameter of the bubble changed from 300 [micrometer] to 50 [micrometer] in 2 cm, which revealed the transition of the acceleration stages from ”bubble expanding mode” to ”bubble stabilizing mode”. Moreover, we demonstrated the broad bandwidth frequency domain streak camera (B-FDSC), which can resolve the dynamics of LPAs in single shot. We improved the temporal resolution of B-FDSC to 10 fs by broadening the bandwidth of the probe beam to 100 nm using supercontinuum generation, and we performed a prototype experiment to show that B-FDSC was capable of resolving the evolution of pulse self-steepening and temporal splitting in a single shot.

Laboratory Visualization of Laser-driven Plasma Accelerators in the Bubble Regime

Laboratory Visualization of Laser-driven Plasma Accelerators in the Bubble Regime PDF Author: Peng Dong
Publisher:
ISBN:
Category :
Languages : en
Pages : 258

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Book Description
Accurate single-shot visualization of laser wakefield structures can improve our fundamental understanding of plasma-based accelerators. Previously, frequency domain holography (FDH) was used to visualize weakly nonlinear sinusoidal wakes in plasmas of density n[subscript e] 0.6 x 1019/cm3 that produced few or no relativistic electrons. Here, I address the more challenging task of visualizing highly nonlinear wakes in plasmas of density n[subscript e] ~ 1 to 3 x 1019/cm3 that can produce high-quality relativistic electron beams. Nonlinear wakes were driven by 30 TW, 30 fs, 800 nm pump pulses. When bubbles formed, part of a 400 nm, co-propagating, overlapping probe pulse became trapped inside them, creating a light packet of plasma wavelength dimensions--that is, an optical "bullet"--That I reconstruct by FDH methods. As ne increased, the bullets first appeared at 0.8 x 1019/cm3, the first observation of bubble formation below the electron capture threshold. WAKE simulations confirmed bubble formation without electron capture and the trapping of optical bullets at this density. At n[subscript]1 x 1019/cm3, bullets appeared with high shot-to-shot stability together with quasi-monoenergetic relativistic electrons. I also directly observed the temporal walk-off of the optical bullet from the beam-loaded plasma bubble revealed by FDH phase shift data, providing unprecedented visualization of the electron injection and beam loading processes. There are five chapters in this thesis. Chapter 1 introduces general laser plasma- based accelerators (LPA). Chapter 2 discusses the FDH imaging technique, including the setup and reconstruction process. In 2006, Dr. N.H. Matlis used FDH to image a linear plasma wakefield. His work is also presented in Chapter 2 but with new analyses. Chapter 3, the main part of the thesis, discusses the visualization of LPAs in the bubble regime. Chapter 4 presents the concept of frequency domain tomography. Chapter 5 suggests future directions for research in FDH.

Investigations of the Plasma and Structure Based Accelerators

Investigations of the Plasma and Structure Based Accelerators PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
The objective of our research during the reported period was three-fold: (a) theoretical investigation of novel mechanisms of injection into laser wake field accelerators; (b) theoretical investigation of single-shot frequency domain diagnostics of relativistic plasma wakes, specifically in the context of spatio-temporal evolution of the plasma bubble;(c) experimental and theoretical investigation of laser-driven accelerating structure, specifically in the context of the Surface Wave Accelerator Based on SiC (SWABSIC).

Diagnostics for the Texas Petawatt Laser-plasma Accelerator

Diagnostics for the Texas Petawatt Laser-plasma Accelerator PDF Author: Dongsu Du
Publisher:
ISBN:
Category :
Languages : en
Pages : 204

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Book Description
Since 2004, table-top laser-plasma accelerators (LPAs) driven by ~30fs terwatt laser pulses have produced colimated, nearly mono-energetic eletron bunches with energy up to 1 GeV in laboratories around the world. Large-scale computer simulations show that LPAs can scale to higher energy while retaining high beam quality, but will require laser pulses of higher energy and longer duration than current LPAs. The group of Prof. Mike Downer, in collaboration with the Texas Petawatt (TPW) laser team headed by Prof. Todd Ditmire, is setting up an experiment that uses the TPW laser (1.1 PW, 150 fs) to drive the world's first multi-GeV LPA. This thesis provides a general overview of the TPW-LPA project, including several diagnostic systems for the beam, plasma and laser pulse. Special attention is given to three of the diagnostic systems: (1)A transverse interferometry diagnostic of the plasma density profile created by the TPW laser pulse; (2)A Thomson scattering diagnostic of the self-guided path of the TPW laser pulse through the plasma; (3)An optical transition radiation diagnostic of the accelerated electron bunch exiting the plasma. In each case, basic principles, theoretical background, calculation and simulation results, and preliminary experimental results will be presented.

Laser Wakefield Acceleration

Laser Wakefield Acceleration PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

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Book Description
Particle accelerators enable scientists to study the fundamental structure of the universe, but have become the largest and most expensive of scientific instruments. In this project, we advanced the science and technology of laser-plasma accelerators, which are thousands of times smaller and less expensive than their conventional counterparts. In a laser-plasma accelerator, a powerful laser pulse exerts light pressure on an ionized gas, or plasma, thereby driving an electron density wave, which resembles the wake behind a boat. Electrostatic fields within this plasma wake reach tens of billions of volts per meter, fields far stronger than ordinary non-plasma matter (such as the matter that a conventional accelerator is made of) can withstand. Under the right conditions, stray electrons from the surrounding plasma become trapped within these "wake-fields", surf them, and acquire energy much faster than is possible in a conventional accelerator. Laser-plasma accelerators thus might herald a new generation of compact, low-cost accelerators for future particle physics, x-ray and medical research. In this project, we made two major advances in the science of laser-plasma accelerators. The first of these was to accelerate electrons beyond 1 gigaelectronvolt (1 GeV) for the first time. In experimental results reported in Nature Communications in 2013, about 1 billion electrons were captured from a tenuous plasma (about 1/100 of atmosphere density) and accelerated to 2 GeV within about one inch, while maintaining less than 5% energy spread, and spreading out less than 1/2 milliradian (i.e. 1/2 millimeter per meter of travel). Low energy spread and high beam collimation are important for applications of accelerators as coherent x-ray sources or particle colliders. This advance was made possible by exploiting unique properties of the Texas Petawatt Laser, a powerful laser at the University of Texas at Austin that produces pulses of 150 femtoseconds (1 femtosecond is 10-15 seconds) in duration and 150 Joules in energy (equivalent to the muzzle energy of a small pistol bullet). This duration was well matched to the natural electron density oscillation period of plasma of 1/100 atmospheric density, enabling efficient excitation of a plasma wake, while this energy was sufficient to drive a high-amplitude wake of the right shape to produce an energetic, collimated electron beam. Continuing research is aimed at increasing electron energy even further, increasing the number of electrons captured and accelerated, and developing applications of the compact, multi-GeV accelerator as a coherent, hard x-ray source for materials science, biomedical imaging and homeland security applications. The second major advance under this project was to develop new methods of visualizing the laser-driven plasma wake structures that underlie laser-plasma accelerators. Visualizing these structures is essential to understanding, optimizing and scaling laser-plasma accelerators. Yet prior to work under this project, computer simulations based on estimated initial conditions were the sole source of detailed knowledge of the complex, evolving internal structure of laser-driven plasma wakes. In this project we developed and demonstrated a suite of optical visualization methods based on well-known methods such as holography, streak cameras, and coherence tomography, but adapted to the ultrafast, light-speed, microscopic world of laser-driven plasma wakes. Our methods output images of laser-driven plasma structures in a single laser shot. We first reported snapshots of low-amplitude laser wakes in Nature Physics in 2006. We subsequently reported images of high-amplitude laser-driven plasma "bubbles", which are important for producing electron beams with low energy spread, in Physical Review Letters in 2010. More recently, we have figured out how to image laser-driven structures that change shape while propagating in a single laser shot. The latter techniques, which use t ...

Electron-beam Diagnostics for a Laser-driven Plasma Wakefield Accelerator in the Framework of FLASHForward

Electron-beam Diagnostics for a Laser-driven Plasma Wakefield Accelerator in the Framework of FLASHForward PDF Author: Jan-Patrick Schwinkendorf
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Laser-Plasma Interactions

Laser-Plasma Interactions PDF Author: Dino A. Jaroszynski
Publisher: CRC Press
ISBN: 1584887796
Category : Science
Languages : en
Pages : 454

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Book Description
A Solid Compendium of Advanced Diagnostic and Simulation ToolsExploring the most exciting and topical areas in this field, Laser-Plasma Interactions focuses on the interaction of intense laser radiation with plasma. After discussing the basic theory of the interaction of intense electromagnetic radiation fields with matter, the book covers three ap

Charge Diagnostics for Laser Plasma Accelerators

Charge Diagnostics for Laser Plasma Accelerators PDF Author:
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Languages : en
Pages :

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Book Description
The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. The sensitivity of the Lanex Fast decreased by 1percent per 100 MeV increase of the energy. The linear response of the screen against the charge was verified with charge density and intensity up to 160 pC/mm2 and 0.4 pC/ps/mm2, respectively. For electron beams from the laser plasma accelerator, a comprehensive study of charge diagnostics has been performed using a Lanex screen, an integrating current transformer, and an activation based measurement. The charge measured by each diagnostic was found to be within +/-10 percent.

Summary Report of Working Group 1

Summary Report of Working Group 1 PDF Author:
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Category :
Languages : en
Pages :

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Book Description
Advances in and physics of the acceleration of particles using underdense plasma structures driven by lasers were the topics of presentations and discussions in Working Group 1 of the 2010 Advanced Accelerator Concepts Workshop. Such accelerators have demonstrated gradients several orders beyond conventional machines, with quasi-monoenergetic beams at MeV-GeV energies, making them attractive candidates for next generation accelerators. Workshop discussions included advances in control over injection and laser propagation to further improve beam quality and stability, detailed diagnostics and physics models of the acceleration process, radiation generation as a source and diagnostic, and technological tools and upcoming facilities to extend the reach of laser-plasma accelerators.

Applications of Laser-Driven Particle Acceleration

Applications of Laser-Driven Particle Acceleration PDF Author: Paul Bolton
Publisher: CRC Press
ISBN: 042981710X
Category : Science
Languages : en
Pages : 388

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Book Description
The first book of its kind to highlight the unique capabilities of laser-driven acceleration and its diverse potential, Applications of Laser-Driven Particle Acceleration presents the basic understanding of acceleration concepts and envisioned prospects for selected applications. As the main focus, this new book explores exciting and diverse application possibilities, with emphasis on those uniquely enabled by the laser driver that can also be meaningful and realistic for potential users. It also emphasises distinction, in the accelerator context, between laser-driven accelerated particle sources and the integrated laser-driven particle accelerator system (all-optical and hybrid versions). A key aim of the book is to inform multiple, interdisciplinary research communities of the new possibilities available and to inspire them to engage with laser-driven acceleration, further motivating and advancing this developing field. Material is presented in a thorough yet accessible manner, making it a valuable reference text for general scientific and engineering researchers who are not necessarily subject matter experts. Applications of Laser-Driven Particle Acceleration is edited by Professors Paul R. Bolton, Katia Parodi, and Jörg Schreiber from the Department of Medical Physics at the Ludwig-Maximilians-Universität München in München, Germany. Features: Reviews the current understanding and state-of-the-art capabilities of laser-driven particle acceleration and associated energetic photon and neutron generation Presents the intrinsically unique features of laser-driven acceleration and particle bunch yields Edited by internationally renowned researchers, with chapter contributions from global experts