Advanced

Transverse expansion of the electron sheath during laser acceleration of protons

Svensson, K. LU ; Mackenroth, F.; Senje, L. LU ; Gonoskov, A.; Harvey, C.; Aurand, B. LU ; Hansson, M. LU ; Higginson, A.; Dalui, M. LU and Lundh, O. LU , et al. (2017) In Physics of Plasmas 24(12).
Abstract

The transverse expansion of the electrostatic sheath during target normal sheath acceleration of protons is investigated experimentally using a setup with two synchronized laser pulses. With the pulses spatially separated by less than three laser spot diameters, the resulting proton beam profiles become elliptical. By introducing a small intensity difference between the two pulses, the ellipses are rotated by a certain angle, except if the spatial separation of the two laser pulses is in the plane of incidence. The rotation angle is shown to depend on the relative intensity of the two pulses. The observed effects are found to require high temporal contrasts of the laser pulses. A simple model describing how the transverse shape of the... (More)

The transverse expansion of the electrostatic sheath during target normal sheath acceleration of protons is investigated experimentally using a setup with two synchronized laser pulses. With the pulses spatially separated by less than three laser spot diameters, the resulting proton beam profiles become elliptical. By introducing a small intensity difference between the two pulses, the ellipses are rotated by a certain angle, except if the spatial separation of the two laser pulses is in the plane of incidence. The rotation angle is shown to depend on the relative intensity of the two pulses. The observed effects are found to require high temporal contrasts of the laser pulses. A simple model describing how the transverse shape of the electron sheath on the rear of the target depends on the relative intensity between the foci is presented. The model assumptions are verified, and the unknown dependence of the transverse extents of the sheaths are estimated self-consistently through a series of high resolution, two-dimensional particle-in-cell simulations. The results predicted by the model are also shown to be consistent with those obtained from the experiment.

(Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physics of Plasmas
volume
24
issue
12
publisher
American Institute of Physics
external identifiers
  • scopus:85038441415
ISSN
1070-664X
DOI
10.1063/1.5010173
language
English
LU publication?
yes
id
302f5bd3-6817-49f5-9151-5b0325dabae3
date added to LUP
2018-01-04 08:10:56
date last changed
2018-01-05 07:04:41
@article{302f5bd3-6817-49f5-9151-5b0325dabae3,
  abstract     = {<p>The transverse expansion of the electrostatic sheath during target normal sheath acceleration of protons is investigated experimentally using a setup with two synchronized laser pulses. With the pulses spatially separated by less than three laser spot diameters, the resulting proton beam profiles become elliptical. By introducing a small intensity difference between the two pulses, the ellipses are rotated by a certain angle, except if the spatial separation of the two laser pulses is in the plane of incidence. The rotation angle is shown to depend on the relative intensity of the two pulses. The observed effects are found to require high temporal contrasts of the laser pulses. A simple model describing how the transverse shape of the electron sheath on the rear of the target depends on the relative intensity between the foci is presented. The model assumptions are verified, and the unknown dependence of the transverse extents of the sheaths are estimated self-consistently through a series of high resolution, two-dimensional particle-in-cell simulations. The results predicted by the model are also shown to be consistent with those obtained from the experiment.</p>},
  articleno    = {123109},
  author       = {Svensson, K. and Mackenroth, F. and Senje, L. and Gonoskov, A. and Harvey, C. and Aurand, B. and Hansson, M. and Higginson, A. and Dalui, M. and Lundh, O. and McKenna, P. and Persson, A. and Marklund, M. and Wahlström, C. G.},
  issn         = {1070-664X},
  language     = {eng},
  month        = {12},
  number       = {12},
  publisher    = {American Institute of Physics},
  series       = {Physics of Plasmas},
  title        = {Transverse expansion of the electron sheath during laser acceleration of protons},
  url          = {http://dx.doi.org/10.1063/1.5010173},
  volume       = {24},
  year         = {2017},
}