%0 Conference Paper %F Oral %T Observations of longitudinal and transverse self-injections in laser-plasma wakefield accelerators %+ Laboratoire d'optique appliquée (LOA) %A Thaury, Cédric %A Corde, Sébastien %A Lifschitz, Agustin %A Lambert, Guillaume %A Ta Phuoc, Kim %A Davoine, X. %A Lehe,, R. %A Douillet, D. %A Rousse, Antoine %A Malka, Victor %< avec comité de lecture %B Conference on Laser Acceleration of Electrons, Protons, and Ions II; and Medical Applications of Laser-Generated Beams of Particles II; and Harnessing Relativistic Plasma Waves III %C Prague, Czech Republic %8 2013-04-15 %D 2013 %R 10.1117/12.2017422 %K Laser-plasma accelerator %K self-injection %K stability %K transverse injection %K longitudinal injection %Z Physics [physics]/Physics [physics]/Optics [physics.optics] %Z Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph]Conference papers %X One of the key ingredients of laser-plasma accelerators is their injector, which defines how electrons are trapped into the laser-driven plasma wave. The stability and control of laser-plasma electron bunches strongly depends on this injection stage. Self-injection is a convenient way to achieve the electron trapping and is the most widely used injector. Here we demonstrate, by using a variable length gas cell, that injection can be achieved by either longitudinal or transverse self-injection, giving rise to very different electron beam features. The results are supported by 3 dimensional particle-in-cell simulations. %G English %L hal-01402024 %U https://hal-ensta-paris.archives-ouvertes.fr/hal-01402024 %~ X %~ ENSTA %~ CNRS %~ X-LOA %~ X-DEP %~ X-DEP-PHYS %~ ENSTA_LOA