An electron-injector for laser-plasma accelerators
Date Issued
2005
Date
2005
Author(s)
Chien, Ting-Yei
DOI
zh-TW
Abstract
acceleration of electrons in a plasma has the potential of
becoming the next-generation particle
accelerator. The acceleration gradient of the
plasma wave can reach several GeV/cm for 1x10^19 cm^-3
plasma density, which is about three orders of magnitude larger than
the conventional radio-frequency linac. Such a large gradient holds
the promise of a compact high-energy electron source.
The first chapter of this thesis gives an introductory
to the history of the development of laser-wakefield accelerators.
The second chapter contains the physical background on plasma wave excitation
and electron acceleration.
The design of electron injectors for laser-wakefield accelerators is aimed
at producing high quality electron beam. To obtain an electron beam with small energy spread and short
duration, electrons must be injected in a single bucket of the
plasma wave at a spatially localized position, which is difficult to
achieve with a radio-frequency electron gun. Several proposed electron injector
schemes are disscussed in chapter 3. The methods of injection of electrons by using a transient
laser-induced plasma density ramp and injection of electrons by a transverse
plasma waveguide are used in our experiment.
The experimental results are discussed in chapter 4.
An electron-injector scheme for laser-wakefield accelerators is demonstrated by
using a laser-induced transient plasma density ramp.
Number of injected electrons reaches 1.7x10^8.
The advantage of this ramp-injection scheme is that it's less sensitive to spatial/ temporal fluctuations
of the laser system and requires less laser energy compared
with most of other proposed injection schemes.
Electron injection in this scheme is spatially localized and can be combined
with the technique of generating a single bucket plasma wave to produce
high quality electron beam. Injection of electrons with comparable efficiency is also demonstrated
by using a transverse plasma waveguide.
Future work based on this ramp injection scheme is proposed in chapter 5.
Subjects
電漿波
電子加速器
plasma wave
high power laser
electron accelerator
Type
thesis