Speaker
Aaron Alejo
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P5.2017.pdf
Characterisation of laser-driven positron beams
for injection in secondary stages
A. Alejo1, G. Sarri1
1 Centre for Plasma Physics, Queen’s University Belfast, United Kingdom
The generation of high-quality relativistic positron beams has gained significant attention in
experimental physics, due to their potential relevance in a wide range of scientific and
engineering areas, ranging from fundamental science to practical applications.
Optimising the spectral and spatial quality of these beams is crucial not only for these
applications, but also for the possibility of using these laser-driven sources as injectors for
further stages of acceleration, being them plasma-based or radio-frequency.
Here we report on experimental and numerical results on determining and optimising the
emittance of these beams, whilst preserving high peak current. This work is justified by the
necessity of generating small-scale and rather inexpensive positron beam accelerators with
superior spatial and spectral qualities. For instance, these results indicate that ultra-relativistic
and high-current positron beams with geometrical emittance below 0.1mm·mrad can be
generated using already existing technology. This value is already comparable to the emittance
in more conventional radio-frequency positron accelerators, such as the LEP injector (0.2
mm·mrad), indicating the possibility of direct injection without the necessity of beam
manipulation and storage.
These results are of central importance for the development of laser-driven particle sources
and, in perspective, for the construction of an all-optical electron-positron collider, main
interest of several national and international projects world-wide, such as the European-funded
EuPRAXIA.
References:
[1] G. Sarri et al., Phys. Rev. Lett. 110, 255002 (2013).
[2] G. Sarri et al., Plasma Physics Controlled Fusion 59, 014015 (2016).
[3] G. Sarri et al., Plasma Physics Controlled Fusion 55, 124017 (2013).
[4] A. Alejo and G. Sarri, Plasma Physics Controlled Fusion, to be submitted (2018).
[5] EuPRAXIA: http://www.eupraxia-project.eu/
