Recent Progress on Laser Produced Positron Research At LLN*

We report the recent results on laser-produced relativistic electron-positron plasma jets. This includes: the prepulse [1] and material dependence of pair generation [2]; time dependent positron acceleration [3] and maximum achieved pair density [4]. We will highlight the results from recent experiments on the Omega EP laser testing nanostructured target to increase pair yield.~ ~We will also report on a newly commissioned platform using the NIF ARC lasers which was developed for efficient pair creation using 10 ps laser duration at near relativistic laser intensity. [1] Jaebum Park \textit{et a}l., High Power Laser Science and Engineering\textbf{ 4} 26 (2016) [2] G. Jackson Williams \textit{et a}l,, Physics of Plasmas\textbf{ 2}3, 123109 (2016) [3] Shaun Kerr \textit{et al}., this conference. [4] Brandon Edghill \textit{et al}., this conference.