The effect of target thickness, molecular composition and pulse length on the proton beam flux and conversion efficiency

Summary form only given. We report on recent experimental studies on the variations in proton conversion efficiency as a function of target thickness, molecular composition and laser pulse length. Experiments were carried out on the Titan laser at LLNL at laser intensities (10¹⁸-10²⁰) and pulse lengths (0.7-5 ps). Erbium hydride was added to the rear surface of the target to study the effect of the molecular composition on the proton beam flux and conversion efficiency. The erbium hydride is a high-Z material that minimizes depletion and increases conversion efficiency. Three different targets thicknesses were used to determine the optimal target thickness to maximize conversion efficiency. Each thickness was analyzed with and without erbium hydride. Experimental results and LSP (large-scale plasma) modeling will be discussed.