Proton, electron and K-alpha emission from micro-scale copper cone targets

Summary form only given. Results from experiments performed at the recently commissioned LANL 200 TW Trident short-pulse laser at ~5??10¹⁹ W/cm² (80-100 J and ~600 fs) are presented. We have conducted laser-ion acceleration experiments comparing flat foils and new Cu micro-cone targets in three separate geometries (flat-top, funnel, and snub-nose) to elucidate the production of hot electrons and ions in these cones, which have been shown to produce higher proton energies and conversion efficiencies than flat foils at lower laser intensity and energy (~1??10¹⁹ W/cm², 20 J). Data from a Cu K?? 2D imaging crystal, an X-ray single hit CCD, proton beam images on RCF film stacks, and an electron/proton spectrometer are presented and compared, showing the importance of not just generating hot electrons, but efficiently propagating these hot electrons to the accelerating "tip", where they can then be efficiently converted to ion energy.