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Laser-Produced Plasmas for Particle Acceleration

Svensson, Kristoffer LU (2012)
Abstract
This thesis describes experimental studies that aim to stabilise

and optimise laser-based particle accelerators. The technique is

called laser wakefield acceleration, where electric fields of the order of 102 GV/m accelerate electrons to high energies (⇠102 MeV)

over mm-distances in laser-produced plasmas.

Among the prerequisites for this acceleration technique to produce

electron beams are laser intensities higher than 1018W/cm2 and sub-ps laser-pulse durations, both of which have seen rapid development since the invention of chirped pulse amplification.

The laser is focused in a gas, which instantly ionises. In the created plasma, the propagating laser pulse creates a wave,... (More)
This thesis describes experimental studies that aim to stabilise

and optimise laser-based particle accelerators. The technique is

called laser wakefield acceleration, where electric fields of the order of 102 GV/m accelerate electrons to high energies (⇠102 MeV)

over mm-distances in laser-produced plasmas.

Among the prerequisites for this acceleration technique to produce

electron beams are laser intensities higher than 1018W/cm2 and sub-ps laser-pulse durations, both of which have seen rapid development since the invention of chirped pulse amplification.

The laser is focused in a gas, which instantly ionises. In the created plasma, the propagating laser pulse creates a wave, which

can accelerate injected electrons. Under the right experimental

conditions, the injection mechanism is automatic, and is called

self-injection. The conditions required for self-injection to occur

are experimentally explored and presented in the thesis. In addition

to the accelerated electrons, collimated beams of x-rays,

called betatron radiation, are produced during the interaction.

The thesis also discusses several ways to enhance important

parameters, such as relative energy spread and divergence, of the

resulting particle beams, which is important for future applications.

By using smart target designs, it is possible to reduce both

the spectral and spatial spread of laser wakefield accelerated electrons.

In the experiment where density-downramp injection was

implemented, relative energy spreads as low as 1% were achieved.

During the experiment when the target consisted of a gas-filled

capillary, the x-ray fluence was increased by a factor of ten when

compared to betatron radiation generated in a supersonic gas jet.

It is also shown in the thesis that the choice of gas is important,

and increased stability is achieved if hydrogen is used as target

gas instead of helium. (Less)
Please use this url to cite or link to this publication:
author
supervisor
organization
publishing date
type
Thesis
publication status
published
subject
pages
74 pages
publisher
Division of Atomic Physics, Department of Physics, Faculty of Engineering, LTH, Lund University
language
English
LU publication?
yes
id
95bebfb0-be7b-4fec-a554-768d427fd765 (old id 2544684)
date added to LUP
2012-05-25 13:40:28
date last changed
2016-09-19 08:44:51
@misc{95bebfb0-be7b-4fec-a554-768d427fd765,
  abstract     = {This thesis describes experimental studies that aim to stabilise<br/><br>
and optimise laser-based particle accelerators. The technique is<br/><br>
called laser wakefield acceleration, where electric fields of the order of 102 GV/m accelerate electrons to high energies (⇠102 MeV)<br/><br>
over mm-distances in laser-produced plasmas.<br/><br>
Among the prerequisites for this acceleration technique to produce<br/><br>
electron beams are laser intensities higher than 1018W/cm2 and sub-ps laser-pulse durations, both of which have seen rapid development since the invention of chirped pulse amplification.<br/><br>
The laser is focused in a gas, which instantly ionises. In the created plasma, the propagating laser pulse creates a wave, which<br/><br>
can accelerate injected electrons. Under the right experimental<br/><br>
conditions, the injection mechanism is automatic, and is called<br/><br>
self-injection. The conditions required for self-injection to occur<br/><br>
are experimentally explored and presented in the thesis. In addition<br/><br>
to the accelerated electrons, collimated beams of x-rays,<br/><br>
called betatron radiation, are produced during the interaction.<br/><br>
The thesis also discusses several ways to enhance important<br/><br>
parameters, such as relative energy spread and divergence, of the<br/><br>
resulting particle beams, which is important for future applications.<br/><br>
By using smart target designs, it is possible to reduce both<br/><br>
the spectral and spatial spread of laser wakefield accelerated electrons.<br/><br>
In the experiment where density-downramp injection was<br/><br>
implemented, relative energy spreads as low as 1% were achieved.<br/><br>
During the experiment when the target consisted of a gas-filled<br/><br>
capillary, the x-ray fluence was increased by a factor of ten when<br/><br>
compared to betatron radiation generated in a supersonic gas jet.<br/><br>
It is also shown in the thesis that the choice of gas is important,<br/><br>
and increased stability is achieved if hydrogen is used as target<br/><br>
gas instead of helium.},
  author       = {Svensson, Kristoffer},
  language     = {eng},
  note         = {Licentiate Thesis},
  pages        = {74},
  publisher    = {Division of Atomic Physics, Department of Physics, Faculty of Engineering, LTH, Lund University},
  title        = {Laser-Produced Plasmas for Particle Acceleration},
  year         = {2012},
}