Control of Focusing Forces and Emittances in Plasma-based Accelerators Using Near-hollow Plasma Channels

Control of Focusing Forces and Emittances in Plasma-based Accelerators Using Near-hollow Plasma Channels PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A near-hollow plasma channel, where the plasma density in the channel is much less than the plasma density in the walls, is proposed to provide independent control over the focusing and accelerating forces in a plasma accelerator. In this geometry the low density in the channel contributes to the focusing forces, while the accelerating fields are determined by the high density in the channel walls. The channel also provides guiding for intense laser pulses used for wakefield excitation. Both electron and positron beams can be accelerated in a nearly symmetric fashion. Near-hollow plasma channels can effectively mitigate emittance growth due to Coulomb scattering for high energy physics applications.

Control of Focusing Forces and Emittances in Plasma-based Accelerators Using Near-hollow Plasma Channels

Control of Focusing Forces and Emittances in Plasma-based Accelerators Using Near-hollow Plasma Channels PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A near-hollow plasma channel, where the plasma density in the channel is much less than the plasma density in the walls, is proposed to provide independent control over the focusing and accelerating forces in a plasma accelerator. In this geometry the low density in the channel contributes to the focusing forces, while the accelerating fields are determined by the high density in the channel walls. The channel also provides guiding for intense laser pulses used for wakefield excitation. Both electron and positron beams can be accelerated in a nearly symmetric fashion. Near-hollow plasma channels can effectively mitigate emittance growth due to Coulomb scattering for high energy physics applications.

Tapered Plasma Channels to Phase-lock Accelerating and Focusing Forces in Laser-plasma Accelerators

Tapered Plasma Channels to Phase-lock Accelerating and Focusing Forces in Laser-plasma Accelerators PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

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Book Description
Tapered plasma channels are considered for controlling dephasing of a beam with respect to a plasma wave driven by a weakly-relativistic, short-pulse laser. Tapering allows for enhanced energy gain in a single laser plasma accelerator stage. Expressions are derived for the taper, or longitudinal plasma density variation, required to maintain a beam at a constant phase in the longitudinal and/or transverse fields of the plasma wave. In a plasma channel, the phase velocities of the longitudinal and transverse fields differ, and, hence, the required tapering differs. The length over which the tapered plasma density becomes singular is calculated. Linear plasma tapering as well as discontinuous plasma tapering, which moves beams to adjacent plasma wave buckets, are also considered. The energy gain of an accelerated electron in a tapered laser-plasma accelerator is calculated and the laser pulse length to optimize the energy gain is determined.

Phase Space Dynamics in Plasma Based Wakefield Acceleration

Phase Space Dynamics in Plasma Based Wakefield Acceleration PDF Author: Xinlu Xu
Publisher: Springer Nature
ISBN: 9811523819
Category : Science
Languages : en
Pages : 138

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Book Description
This book explores several key issues in beam phase space dynamics in plasma-based wakefield accelerators. It reveals the phase space dynamics of ionization-based injection methods by identifying two key phase mixing processes. Subsequently, the book proposes a two-color laser ionization injection scheme for generating high-quality beams, and assesses it using particle-in-cell (PIC) simulations. To eliminate emittance growth when the beam propagates between plasma accelerators and traditional accelerator components, a method using longitudinally tailored plasma structures as phase space matching components is proposed. Based on the aspects above, a preliminary design study on X-ray free-electron lasers driven by plasma accelerators is presented. Lastly, an important type of numerical noise—the numerical Cherenkov instabilities in particle-in-cell codes—is systematically studied.

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator

Properties of Trapped Electron Bunches in a Plasma Wakefield Accelerator PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Plasma-based accelerators use the propagation of a drive bunch through plasma to create large electric fields. Recent plasma wakefield accelerator (PWFA) experiments, carried out at the Stanford Linear Accelerator Center (SLAC), successfully doubled the energy for some of the 42 GeV drive bunch electrons in less than a meter; this feat would have required 3 km in the SLAC linac. This dissertation covers one phenomenon associated with the PWFA, electron trapping. Recently it was shown that PWFAs, operated in the nonlinear bubble regime, can trap electrons that are released by ionization inside the plasma wake and accelerate them to high energies. These trapped electrons occupy and can degrade the accelerating portion of the plasma wake, so it is important to understand their origins and how to remove them. Here, the onset of electron trapping is connected to the drive bunch properties. Additionally, the trapped electron bunches are observed with normalized transverse emittance divided by peak current, [epsilon]{sub N, x}/I{sub t}, below the level of 0.2 [mu]m/kA. A theoretical model of the trapped electron emittance, developed here, indicates that the emittance scales inversely with the square root of the plasma density in the non-linear 'bubble' regime of the PWFA. This model and simulations indicate that the observed values of [epsilon]{sub N, x}/I{sub t} result from multi-GeV trapped electron bunches with emittances of a few [mu]m and multi-kA peak currents. These properties make the trapped electrons a possible particle source for next generation light sources. This dissertation is organized as follows. The first chapter is an overview of the PWFA, which includes a review of the accelerating and focusing fields and a survey of the remaining issues for a plasma-based particle collider. Then, the second chapter examines the physics of electron trapping in the PWFA. The third chapter uses theory and simulations to analyze the properties of the trapped electron bunches. Chapters four and five present the experimental diagnostics and measurements for the trapped electrons. Next, the sixth chapter introduces suggestions for future trapped electron experiments. Then, Chapter seven contains the conclusions. In addition, there is an appendix chapter that covers a topic which is extraneous to electron trapping, but relevant to the PWFA. This chapter explores the feasibility of one idea for the production of a hollow channel plasma, which if produced could solve some of the remaining issues for a plasma-based collider.

Demonstration of the Hollow Channel Plasma Wakefield Accelerator

Demonstration of the Hollow Channel Plasma Wakefield Accelerator PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 192

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Book Description
A plasma wakefield accelerator is a device that converts the energy of a relativistic particle beam into a large-amplitude wave in a plasma. The plasma wave, or wakefield, supports an enormous electricfield that is used to accelerate a trailing particle beam. The plasma wakefield accelerator can therefore be used as a transformer, transferring energy from a high-charge, low-energy particle beam into a high-energy, low-charge particle beam. This technique may lead to a new generation of ultra-compact, high-energy particle accelerators. The past decade has seen enormous progress in the field of plasma wakefield acceleration with experimental demonstrations of the acceleration of electron beams by several gigaelectron-volts. The acceleration of positron beams in plasma is more challenging, but also necessary for the creation of a high-energy electron-positron collider. Part of the challenge is that the plasma responds asymmetrically to electrons and positrons, leading to increased disruption of the positron beam. One solution to this problem, first proposed over twenty years ago, is to use a hollow channel plasma which symmetrizes the response of the plasma to beams of positive and negative charge, making it possible to accelerate positrons in plasma without disruption. In this thesis, we describe the theory relevant to our experiment and derive new results when needed. We discuss the development and implementation of special optical devices used to create long plasma channels. We demonstrate for the first time the generation of meter-scale plasma channels and the acceleration of positron beams therein.

Theoretical Investigations of Plasma-Based Accelerators and Other Advanced Accelerator Concepts

Theoretical Investigations of Plasma-Based Accelerators and Other Advanced Accelerator Concepts PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
Theoretical investigations of plasma-based accelerators and other advanced accelerator concepts. The focus of the work was on the development of plasma based and structure based accelerating concepts, including laser-plasma, plasma channel, and microwave driven plasma accelerators.

Plasma-based Accelerator Structures

Plasma-based Accelerator Structures PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 106

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Book Description
Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

Cells in Space

Cells in Space PDF Author: Jean D. Sibonga
Publisher:
ISBN:
Category : Bioreactors
Languages : en
Pages : 340

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Book Description
Discussions and presentations addressed three aspects of cell research in space: the suitability of the cell as a subject in microgravity experiments, the requirements for generic flight hardware to support cell research, and the potential for collaboration between academia, industry, and government to develop these studies in space. Synopses are given for the presentations and follow-on discussions at the conference and papers are presented from which the presentations were based. An Executive Summary outlines the recommendations and conclusions generated at the conference.

Applications of Closed-cycle Cryocoolers to Small Superconducting Devices

Applications of Closed-cycle Cryocoolers to Small Superconducting Devices PDF Author: United States. National Bureau of Standards
Publisher:
ISBN:
Category : Refrigeration and refrigerating machinery
Languages : en
Pages : 264

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Book Description


Policies to Support the Development of Indonesia’s Manufacturing Sector during 2020–2024

Policies to Support the Development of Indonesia’s Manufacturing Sector during 2020–2024 PDF Author:
Publisher: Asian Development Bank
ISBN: 9292614894
Category : Business & Economics
Languages : en
Pages : 470

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Book Description
Indonesia's gross domestic product growth rate declined significantly after the Asian financial crisis (AFC) of 1997–1998. The country's potential and balance-of-payments growth rates are only about 5.5% and 3%, respectively. One important reason is that the country's industrialization pace declined after the AFC. Today, Indonesia is still exporting many unprocessed natural resources and simple manufactures (not complex products) with a low income elasticity of demand. This report analyzes how Indonesia's manufacturing sector could diversify and upgrade during 2020–2024 and beyond. This is essential if Indonesia is to attain upper middle-income status as soon as possible. Policy makers and the private sector need to collaborate to identify the coordination failures that hamper the discovery of those products that Indonesia could successfully produce and export. These must be complex products with a high income elasticity of demand. The report proposes a number of policies to expedite this process.