Channel Fields and Transverse Ion Acceleration from High-Intensity Laser Interactions with Underdense Plasma on OMEGA EP

Experiments were performed at the OMEGA EP laser facility wherein a laser pulse was focused into a helium gas jet, forming an electron depleted channel through the underdense plasma. The charge separation in this channel creates a strong transverse electric field that accelerates ions radially through a Coulomb explosion. With proton deflectometry measurements, we aim to understand the scale and strength of these channel fields. The transversely accelerated helium ions, measured with a Thomson Parabola Ion Energy (TPIE) spectrometer, provide a complementary measurement for understanding these same electric field strengths. The work presented here is relevant to investigating the channel formation during direct laser acceleration (DLA) experiments as it is the same radial channel field, along with the electron beam-generated azimuthal magnetic field, that facilitates DLA.



This work is supported by the Department of Energy / NNSA under Award Number DE-NA0004203 and DE-SC0021057 . The experiment was conducted at the Omega Laser Facility at the University of Rochester’s Laboratory for Laser Energetics with the beam time through the National Laser Users Facility (NLUF) program. The OSIRIS Consortium (UCLA and IST, Lisbon, Portugal) is acknowledged for providing access to the OSIRIS 4.0 framework. Work supported by NSF ACI-1339893.